Effects of work hour reduction on residents' lives: a systematic review

Context  The Accreditation Council for Graduate Medical Education implemented mandatory work hour limitations in July 2003, partly out of concern for residents’ well-being in the setting of sleep deprivation. These limitations are likely to also have an impact on other aspects of the lives of residents. Objective  To summarize the literature regarding the effect of interventions to reduce resident work hours on residents’ education and quality of life. Data Sources  We searched the English-language literature about resident work hours from 1966 through April 2005 using MEDLINE, EMBASE, and Current Contents, supplemented with hand-search of additional journals, reference list review, and review of abstracts from national meetings. Study Selection  Studies were included that assessed a system change designed to counteract the effects of resident work hours, fatigue, or sleep deprivation; included an outcome directly related to residents; and were conducted in the United States. Data Extraction  For each included study, 2 investigators independently abstracted data related to study quality, subjects, interventions, and findings using a standard data abstraction form. Data Synthesis  Fifty-four articles met inclusion criteria. The interventions used to decrease resident work hours varied but included night and day float teams, extra cross-coverage, and physician extenders. Outcomes included measures of resident education (operative experience, test scores, satisfaction) and quality of residents’ lives (amount of sleep, well-being). Interventions to reduce resident work hours resulted in mixed effects on both operative experience and on perceived educational quality but generally improved residents’ quality of life. Many studies had major limitations in their design or conduct. Conclusions  Past interventions suggest that residents’ quality of life may improve with work hour limitations, but interpretation of the outcomes of these studies is hampered by suboptimal study design and the use of nonvalidated instruments. The long-term impact of reducing resident work hours on education remains unknown. Current and future interventions should be evaluated with more rigorous methods and should investigate links between residents’ quality of life and quality of patient care.      

Resident burnout

Intense work demands, limited control, and a high degree of work-home interference abound in residency training programs and should strongly predispose resident physicians to burnout as they do other health care professionals. This article reviews studies in the medical literature that address the level of burnout and associated personal and work factors, health and performance issues, and resources and interventions in residents. MEDLINE and PubMed databases were searched for peer-reviewed, English-language studies reporting primary data on burnout or dimensions of burnout among residents, published between 1983 and 2004, using combinations of the Medical Subject Heading terms burnout, professional, emotional exhaustion, cynicism, depersonalization and internship and residency, housestaff, intern, resident, or physicians in training and by examining reference lists of retrieved articles for relevant studies. A total of 15 heterogeneous articles on resident burnout were thus identified. The studies suggest that burnout levels are high among residents and may be associated with depression and problematic patient care. However, currently available data are insufficient to identify causal relationships and do not support using demographic or personality characteristics to identify at-risk residents. Moreover, given the heterogeneous nature and limitations of the available studies, as well as the importance of having rigorous data to understand and prevent resident burnout, large, prospective studies are needed.      

Excessive Daytime Sleepiness and Sudden-Onset Sleep in Parkinson Disease: A Survey by the Canadian Movement Disorders Group

Context  Somnolence is a recognized adverse effect of dopamine agonists. Two new dopamine agonists, pramipexole and ropinirole, have been reported to cause sudden-onset sleep spells in patients with Parkinson disease (PD) while they were driving. The frequency of these spells and whether driving should be restricted has yet to be established. Objective  To determine the frequency of and predictors for sudden-onset sleep and, particularly, episodes of falling asleep while driving among patients with PD. Design, Setting, and Participants  Prospective survey conducted between January and April 2000 in 18 clinics directed by members of the Canadian Movement Disorders Group; 638 consecutive highly functional PD patients without dementia were enrolled, of whom 420 were currently drivers. Main Outcome Measures  Excessive daytime sleepiness and sudden-onset sleep as assessed by the Epworth Sleepiness Scale and the Inappropriate Sleep Composite Score. The latter score, designed for this study, addressed falling asleep in unusual circumstances. The 2 scales were combined in 3 separate formats: dozing off, sudden unexpected sleep, and sudden blank spells. Results  Excessive daytime sleepiness was present overall in 327 (51%) of the 638 patients and in 213 (51%) of the 420 drivers. Patients taking a variety of different dopamine agonists had no differences in Epworth sleepiness scores, in the composite score, or in the risk of falling asleep while driving. Sixteen patients (3.8%) had experienced at least 1 episode of sudden onset of sleep while driving (after the diagnosis of PD); in 3 (0.7%), it occurred without warning. The 2 risk factors associated with falling asleep at the wheel were the Epworth Sleepiness Scale score (odds ratio [OR], 1.14; 95% confidence interval [CI], 1.06-1.24) and the Inappropriate Sleep Composite Score (OR, 2.54; 95% CI, 1.76-3.66). A standard Epworth Sleepiness Scale score of 7 or higher predicted 75% of episodes of sleep behind the wheel at a specificity of 50% (exclusion of the question related to driving provided 70% sensitivity and 52% specificity), whereas a score of 1 on the Inappropriate Sleep Composite Score generated a sensitivity of 52% and specificity of 82%. Conclusions  Excessive daytime sleepiness is common even in patients with PD who are independent and do not have dementia. Sudden-onset sleep without warning is infrequent. The Epworth score has adequate sensitivity for predicting prior episodes of falling asleep while driving and its specificity can be increased by use of the Inappropriate Sleep Composite Score. It is unknown if routinely performing these assessments could be more effective in predicting future risk for these rare sleep attacks. Patients should be warned not to drive if they doze in unusual circumstances.      

Preparedness for clinical practice: reports of graduating residents at academic health centers

Context  Medical educators are seeking improved measures to assess the clinical competency of residents as they complete their graduate medical education. Objective  To assess residents' perceptions of their preparedness to provide common clinical services during their last year of graduate medical education. Design, Setting, and Participants  A 1998 national survey of residents completing their training in 8 specialties (internal medicine, pediatrics, family practice, obstetrics/gynecology, general surgery, orthopedic surgery, psychiatry, and anesthesiology) at academic health centers in the United States. A total of 2626 residents responded (response rate, 65%). Main Outcome Measures  Residents' reports of their preparedness to perform clinical and nonclinical tasks relevant to their specialties. Results  Residents in all specialties rated themselves as prepared to manage most of the common conditions they would encounter in their clinical career. However, more than 10% of residents in each specialty reported that they felt unprepared to undertake 1 or more tasks relevant to their disciplines, such as caring for patients with human immunodeficiency virus/acquired immunodeficiency syndrome or substance abuse (family practice) or nursing home patients (internal medicine); performance of spinal surgery (orthopedic surgery) or abdominal aortic aneurysm repair (general surgery); and management of chronic pain (anesthesiology). Conclusions  Overall, residents in their last year of training at academic health centers rate their clinical preparedness as high. However, opportunities for improvement exist in preparing residents for clinical practice.      

Longitudinal study of moderate weight change and sleep-disordered breathing

Context  Excess body weight is positively associated with sleep-disordered breathing (SDB), a prevalent condition in the US general population. No large study has been conducted of the longitudinal association between SDB and change in weight. Objective  To measure the independent longitudinal association between weight change and change in SDB severity. Design  Population-based, prospective cohort study conducted from July 1989 to January 2000. Setting and Participants  Six hundred ninety randomly selected employed Wisconsin residents (mean age at baseline, 46 years; 56% male) who were evaluated twice at 4-year intervals for SDB. Main Outcome Measures  Percentage change in the apnea-hypopnea index (AHI; apnea events + hypopnea events per hour of sleep) and odds of developing moderate-to-severe SDB (defined by an AHI 15 events per hour of sleep), with respect to change in weight. Results  Relative to stable weight, a 10% weight gain predicted an approximate 32% (95% confidence interval [CI], 20%-45%) increase in the AHI. A 10% weight loss predicted a 26% (95% CI, 18%-34%) decrease in the AHI. A 10% increase in weight predicted a 6-fold (95% CI, 2.2-17.0) increase in the odds of developing moderate-to-severe SDB. Conclusions  Our data indicate that clinical and public health programs that result in even modest weight control are likely to be effective in managing SDB and reducing new occurrence of SDB.      

Claims of sex differences: an empirical assessment in genetic associations

Context  Many studies try to probe for differences in risks between men and women, and this is a major challenge in the expanding literature of associations between genetic variants and common diseases or traits. Objective  To evaluate whether prominently claimed sex differences for genetic effects have sufficient internal and external validity. Data Sources  We searched PubMed through July 6, 2007, for genetic association studies claiming sex-related differences in the articles' titles. Titles and abstracts and, if necessary, the full text of the article were assessed for eligibility. Study Selection  Two hundred fifteen articles were retrieved by the search. We considered eligible all retrieved association studies that claimed different genetic effects across sexes of 1 or more gene variants for any human disease or phenotype. We considered both biallelic and multiallelic markers (including haplotypes) and both binary and continuous phenotypes and traits. We excluded non–English-language studies; studies evaluating only 1 sex; studies in which sex was treated only as an independent predictor of disease; studies that did not address any association of the investigated genetic variant with a disease or trait; studies not involving humans; and studies in which the authors did not claim any sex difference. Data Extraction  Two evaluators independently extracted data with a third evaluator arbitrating their discrepancies. Data evaluation included whether analyses were stated to have been specified a priori; whether sex effects were evaluated in the whole study or subgroups thereof; and whether the claims were appropriately documented, insufficiently documented, or spurious. For appropriately and insufficiently documented claims we performed the calculations for gene-sex interaction whenever raw data were available. Finally, we compared the sex-difference claims with the best internal validity against the results of other studies addressing the same interaction. Results  We appraised 432 sex-difference claims in 77 eligible articles. Authors stated that sex comparisons were decided a priori for 286 claims (66.2%), while the entire sample size was used in 210 (48.6%) claims. Appropriate documentation of gene-sex interaction was recorded in 55 claims (12.7%); documentation was insufficient for 303 claims and spurious for the other 74. Data for reanalysis of claims were available for 188 comparisons. Of these, 83 (44.1%) were nominally statistically significant at a P = .05 threshold, and more than half of them (n = 44) had modest P values between .01 and .05. Of 60 claims with seemingly the best internal validity, only 1 was consistently replicated in at least 2 other studies. Conclusion  In this sample of highly prominent claims of sex-related differences in genetic associations, most claims were insufficiently documented or spurious, and claims with documented good internal and external validity were uncommon.      

Efficacy of a hip protector to prevent hip fracture in nursing home residents: the HIP PRO randomized controlled trial

Context  Past studies of the efficacy of hip protectors to prevent hip fracture in nursing home residents have had conflicting results, possibly due to potential biases from clustered randomization designs and modest adherence to intervention. Objective  To determine whether an energy-absorbing and energy-dispersing hip protector would reduce the risk of hip fracture when worn by nursing home residents. Design, Setting, and Participants  Multicenter, randomized controlled clinical trial in which 37 nursing homes were randomly assigned to having residents wear a 1-sided hip protector on the left or right hip. Participants were 1042 nursing home residents (mean [SD] aged 85 [7] years; 79% women) who consented and adhered to the hip protector use during a 2-week run-in period and were enrolled. Participating facilities were in greater Boston, Massachusetts, St Louis, Missouri, and Baltimore, Maryland from October 2002 to October 2004. Mean duration of participation for nursing home residents was 7.8 months. None were withdrawn because of adverse effects. Intervention(s)  Undergarments with a 1-sided hip protector made of a 0.32-cm outer layer of polyethylene (2.7 kg/m³) backed by a hard high-density polyethylene shield (0.95 cm) that was backed by 0.9 kg/m³ of 1.27-kg ethylene vinyl acetate foam. Each facility was visited 3 times per week to assess adherence and provide staff support. Main Outcome Measure  Adjudicated hip fracture occurrences on padded vs unpadded hips. Results  After a 20-month follow-up (676 person-years of observation), the study was terminated due to a lack of efficacy. The incidence rate of hip fracture on protected vs unprotected hips did not differ (3.1%; 95% confidence interval [CI], 1.8%-4.4% vs 2.5%; 95% CI, 1.3%-3.7%; P = .70). For the 334 nursing home residents with greater than 80% adherence to hip protector use, the incidence rate of hip fracture on protected vs unprotected hips did not differ (5.3%; 95% CI, 2.6%-8.8% vs 3.5%; 95% CI, 1.3%-5.7%; P = .42). Overall adherence was 73.8%. Conclusions  In this clinical trial of an energy-absorbing/shunting hip protector conducted in US nursing homes, we were unable to detect a protective effect on the risk of hip fracture, despite good adherence to protocol. These results add to the increasing body of evidence that hip protectors, as currently designed, are not effective for preventing hip fracture among nursing home residents. Trial Registration  clinicaltrials.gov Identifier: NCT00058864      

Obstructive sleep apnea: implications for cardiac and vascular disease

Context  Obstructive sleep apnea (OSA) has been increasingly implicated in the initiation and progression of cardiovascular diseases. Objective  To systematically review the interactions of OSA with cardiovascular pathophysiology and diseases. Data Sources and Study Selection  The MEDLINE database from January 1966 to March 2003 was searched using the Medical Subject Headings sleep, sleep apnea, obesity, hypertension, heart failure, cardiac arrhythmia, coronary artery disease, stroke, sympathetic activity, endothelium, inflammation, and continuous positive airway pressure (CPAP) to identify peer-reviewed studies of OSA. Priority was given to large prospective cohort studies and to randomized controlled trials. Data Extraction  We identified 154 original investigations and reviews of sleep-related breathing disorders. Data from these studies were examined for relevance and extracted by one of the authors. Data Synthesis  Approximately 1 in 5 adults has at least mild OSA (apnea-hypopnea index [ie, the number of apneic and hypopneic events per hour], 5-15), and 1 in 15 adults has at least moderate OSA (apnea-hypopnea index, 15-30). Repetitive apneic events disrupt the normal physiologic interactions between sleep and the cardiovascular system. Such sleep fragmentation, as well as abnormalities evident in patients with OSA (eg, increased sympathetic activation, vascular endothelial dysfunction, increased oxidative stress, inflammation, increased platelet aggregability, metabolic dysregulation), may be implicated in the initiation and progression of cardiac and vascular disease. Persuasive data implicate OSA in the development of hypertension, and OSA also may contribute to cardiac ischemia, congestive heart failure, cardiac arrhythmias, and perhaps also to cerebrovascular disease and stroke. Conclusions  Obstructive sleep apnea is common, readily diagnosed, and usually treatable. It frequently coexists undiagnosed in patients with cardiovascular disease, activates disease mechanisms known to elicit cardiac and vascular damage, and may be implicated in progression of cardiovascular disease and resistance to conventional therapeutic strategies. In the absence of definitive evidence from large-scale trials and a better understanding of potential cost-effectiveness, the likely benefits of diagnosis and treatment of OSA are presently best appraised on an individualized patient basis.      

Effects of editorial peer review: a systematic review

Context  Editorial peer review is widely used to select submissions to journals for publication and is presumed to improve their usefulness. Sufficient research on peer review has been published to consider a synthesis of its effects. Methods  To examine the evidence of the effects of editorial peer-review processes in biomedical journals, we conducted electronic and full-text searches of private and public databases to June 2000 and corresponded with the World Association of Medical Editors, European Association of Science Editors, Council of Science Editors, and researchers in the field to locate comparative studies assessing the effects of any stage of the peer-review process that made some attempt to control for confounding. Nineteen of 135 identified studies fulfilled our criteria. Because of the diversity of study questions, methods, and outcomes, we did not pool results. Results  Nine studies considered the effects of concealing reviewer/author identity. Four studies suggested that concealing reviewer or author identity affected review quality (mostly positively); however, methodological limitations make their findings ambiguous, and other studies' results were either negative or inconclusive. One study suggested that a statistical checklist can improve report quality, but another failed to find an effect of publishing another checklist. One study found no evidence that training referees improves performance and another showed increased interrater reliability; both used open designs, making interpretation difficult. Two studies of how journals communicate with reviewers did not demonstrate any effect on review quality. One study failed to show reviewer bias, but the findings may not be generalizable. One nonrandomized study compared the quality of articles published in peer-reviewed vs other journals. Two studies showed that editorial processes make articles more readable and improve the quality of reporting, but the findings may have limited generalizability to other journals. Conclusions  Editorial peer review, although widely used, is largely untested and its effects are uncertain.      

Preparedness of internal medicine and family practice residents for treating common conditions

Context  Although both internal medicine (IM) and family practice (FP) physicians frequently provide care for the same common adult conditions, IM and FP residency programs differ in their training emphases. Objective  To assess differences in IM and FP residents' self-perceived preparedness to diagnose and treat common adult medical conditions. Design, Setting, and Participants  Cross-sectional analysis of a national survey administered in the spring of 1998 to residents in their final year of residency at US academic health centers. A total of 279 IM residents in 25 programs and 326 FP residents in 75 programs responded to the survey. Main Outcome Measures  Residents' self-rated preparedness to diagnose and treat 4 inpatient conditions (acute myocardial infarction, diabetic ketoacidosis, acute asthma, and acute renal failure) and 8 outpatient conditions (diabetes, hypertension, low back pain, vaginitis, headache, depression, upper respiratory tract infection, and hyperlipidemia), controlling for resident sex, race/ethnicity, US medical school graduate status, intent to subspecialize, and estimates of exposure to patients in inpatient and outpatient settings. Results  Internal medicine residents were more likely to report being very prepared for all 4 inpatient conditions (P.001), while FP residents were more likely to report being very prepared for 5 of 8 outpatient conditions (P.05). Differences between IM and FP residents persisted in multivariate analyses for all inpatient conditions and some outpatient conditions. Exposure to patients in inpatient and outpatient settings varied by specialty and was significantly associated with resident self-report of preparedness for a majority of conditions investigated. Conclusions  Internal medicine and FP residents report differences in preparedness to manage common adult conditions. These differences were consistent with the emphasis on an inpatient setting for IM residents and on office-based care for FP residents.      

US graduate medical education, 2003-2004

Context  Information about recent graduates of medical schools and the characteristics of physicians training in graduate medical education (GME) portends the size and composition of the US physician workforce of the near future. Objectives  To examine trends in training programs and career choices of graduating male and female residents and to monitor trends in the size of the entire residency population. Design, Setting, and Participants  The American Medical Association and Association of American Medical Colleges jointly surveyed residency programs during the academic year 2003-2004 about active, transferred, and graduated residents, as well as about program characteristics. The 8192 programs confirmed the status of 94.6% of residents. Nearly 86% of program directors (n = 7040) completed the accompanying program survey. Main Outcome Measures  Overall trends during the last 6 years in the number and characteristics of residents and programs, as well as the specialty of male and female graduating residents. Results  There were 99 964 active residents during the 2003-2004 academic year, the highest ever recorded by the National GME Census. The number of residents (n = 22 444) entering US graduate medical education programs for the first time is also the highest on record. In 1999, 28 773 physicians completed training, 10 546 (36.7%) of whom were women. In 2003, there were 29 745 graduates, 11 681 (39.3%) of whom were women, representing a 10.8% increase. The number of obstetrics/gynecology male graduates decreased 31.3%, while female graduates increased 18.2%. Other specialties that lost men and gained women were dermatology, family medicine, internal medicine, ophthalmology, pathology, psychiatry, and general surgery. The proportion of graduates who pursued additional training increased; percentages were 27.2% in 1999, 29.6% in 2001, and 32.1% in 2003. In 2000, 35.7% of programs provided opportunities to develop cultural competence; the percentage in 2003 was 50.7%. The percentage of programs with complementary/alternative medicine curriculum has held steady at 24%. Conclusions  The number of physicians in GME is at its highest, and nearly one third of physicians completing training in one program continue on in another. The choices of female residents parallel those of male residents in many respects, but there are important differences.      

What clinicians should know about the QT interval

Context  Of the several factors implicated in causing QT interval prolongation and torsades de pointes, errors in the use of medications that may prolong this interval deserve special attention. Objective  To systematically summarize the available clinical data on the QT interval and to offer improved recommendations for the use of QT-prolonging medications. Data Sources  We searched MEDLINE from 1966 through 2002 for all English-language articles related to the QT interval. Additional data sources included bibliographies of articles identified on MEDLINE, a survey of experts, and data presented at a meeting of experts on long QT syndrome. Study Selection  We selected for review registries and case series examining clinical outcomes of patients with prolonged QT interval and the effect of different methods of measurement of the QT interval on patient outcomes. Ten studies were identified, of which 6 were included in the analysis. Data Extraction  Data quality was determined by publication in the peer-reviewed literature. Data Synthesis  Optimal measurement of the QT interval is problematic because of lack of standardization and lack of data regarding the best way to adjust for heart rate. Reliable information on the proper use of QT-prolonging medications is scarce. Although a QT interval of at least 500 milliseconds generally has been shown to correlate with a higher risk of torsades de pointes, there is no established threshold below which prolongation of the QT interval is considered free of proarrhythmic risk. The risk of torsades de pointes should be assessed in patients who are about to begin taking a QT-prolonging medication. Although inadequate clinical studies preclude prediction of absolute risk for individual patients, particularly high-risk situations can be defined based on clinical variables. We propose recommendations on proper monitoring of the QT interval in patients receiving QT-prolonging medications. Conclusion  Although the use of QT-prolonging medications can predispose to torsades de pointes, there is a relative paucity of information that can help clinicians and patients make optimal informed decisions about how best to minimize the risk of this serious complication.      

Bariatric surgery: a systematic review and meta-analysis

Context  About 5% of the US population is morbidly obese. This disease remains largely refractory to diet and drug therapy, but generally responds well to bariatric surgery. Objective  To determine the impact of bariatric surgery on weight loss, operative mortality outcome, and 4 obesity comorbidities (diabetes, hyperlipidemia, hypertension, and obstructive sleep apnea). Data Sources and Study Selection  Electronic literature search of MEDLINE, Current Contents, and the Cochrane Library databases plus manual reference checks of all articles on bariatric surgery published in the English language between 1990 and 2003. Two levels of screening were used on 2738 citations. Data Extraction  A total of 136 fully extracted studies, which included 91 overlapping patient populations (kin studies), were included for a total of 22 094 patients. Nineteen percent of the patients were men and 72.6% were women, with a mean age of 39 years (range, 16-64 years). Sex was not reported for 1537 patients (8%). The baseline mean body mass index for 16 944 patients was 46.9 (range, 32.3-68.8). Data Synthesis  A random effects model was used in the meta-analysis. The mean (95% confidence interval) percentage of excess weight loss was 61.2% (58.1%-64.4%) for all patients; 47.5% (40.7%-54.2%) for patients who underwent gastric banding; 61.6% (56.7%-66.5%), gastric bypass; 68.2% (61.5%-74.8%), gastroplasty; and 70.1% (66.3%-73.9%), biliopancreatic diversion or duodenal switch. Operative mortality (30 days) in the extracted studies was 0.1% for the purely restrictive procedures, 0.5% for gastric bypass, and 1.1% for biliopancreatic diversion or duodenal switch. Diabetes was completely resolved in 76.8% of patients and resolved or improved in 86.0%. Hyperlipidemia improved in 70% or more of patients. Hypertension was resolved in 61.7% of patients and resolved or improved in 78.5%. Obstructive sleep apnea was resolved in 85.7% of patients and was resolved or improved in 83.6% of patients. Conclusions  Effective weight loss was achieved in morbidly obese patients after undergoing bariatric surgery. A substantial majority of patients with diabetes, hyperlipidemia, hypertension, and obstructive sleep apnea experienced complete resolution or improvement.      

The rational clinical examination. Is this patient hypovolemic?

Steven McGee, MD; William B. Abernethy III, MD; David L. Simel, MD, MHS

JAMA. 1999;281:1022-1029.

Objective  To review, systematically, the physical diagnosis of hypovolemia in adults.

Methods  We searched MEDLINE (January 1966-November 1997), personal files, and bibliographies of textbooks on physical diagnosis and identified 10 studies investigating postural vital signs or the capillary refill time of healthy volunteers, some of whom underwent phlebotomy of up to 1150 mL of blood, and 4 studies of patients presenting to emergency departments with suspected hypovolemia, usually due to vomiting, diarrhea, or decreased oral intake.

Results  When clinicians evaluate adults with suspected blood loss, the most helpful physical findings are either severe postural dizziness (preventing measurement of upright vital signs) or a postural pulse increment of 30 beats/min or more. The presence of either finding has a sensitivity for moderate blood loss of only 22% (95% confidence interval [CI], 6%-48%) but a much greater sensitivity for large blood loss of 97% (95% CI, 91%-100%); the corresponding specificity is 98% (95% CI, 97%-99%). Supine hypotension and tachycardia are frequently absent, even after up to 1150 mL of blood loss (sensitivity, 33%; 95% CI, 21%-47%, for supine hypotension). The finding of mild postural dizziness has no proven value. In patients with vomiting, diarrhea, or decreased oral intake, the presence of a dry axilla supports the diagnosis of hypovolemia (positive likelihood ratio, 2.8; 95% CI, 1.4-5.4), and moist mucous membranes and a tongue without furrows argue against it (negative likelihood ratio, 0.3; 95% CI, 0.1-0.6 for both findings). In adults, the capillary refill time and poor skin turgor have no proven diagnostic value.

Conclusions  A large postural pulse change (30 beats/min) or severe postural dizziness is required to clinically diagnose hypovolemia due to blood loss, although these findings are often absent after moderate amounts of blood loss. In patients with vomiting, diarrhea, or decreased oral intake, few findings have proven utility, and clinicians should measure serum electrolytes, serum blood urea nitrogen, and creatinine levels when diagnostic certainty is required.

     

Factors Associated With the Transition to Nonprone Sleep Positions of Infants in the United States: The National Infant Sleep Position Study

Context.— Studies have demonstrated strong associations between the prone sleep position (on the stomach) and sudden infant death syndrome (SIDS). In 1992, the American Academy of Pediatrics recommended that infants be placed to sleep laterally (on their side) or supine (on their back) to reduce SIDS risk, and in 1994, the national public education campaign "Back to Sleep" was launched. Objective.— To determine the typical sleep position of infants younger than 8 months in the United States, the changes that occurred after these recommendations, and the factors associated with the placement of infants prone or supine. Design.— Annual nationally representative telephone surveys. Setting.— The 48 contiguous states of the United States. Participants.— Nighttime caregivers of infants born within the last 7 months between 1992 and 1996. Approximately 1000 interviews were conducted per year. Main Outcome Measures.— The position the infant was usually placed in for sleep, and the position the infant was most commonly found in when checked during the night's sleep. Results.— Ninety-seven percent of respondents in each wave of the survey usually placed their infant to sleep in a specific position. Infants were placed in the prone position by 70% of caregivers in 1992, prior to the campaign, but only 24% in 1996. Supine and lateral placements increased during this time period, from 13% in 1992 to 35% in 1996 and from 15% in 1992 to 39% in 1996, respectively. Significant predictors of prone placement included maternal race reported as black (odds ratio [OR], 2.34; 95% confidence interval [CI], 1.68-3.26), mother's age 20 to 29 years (OR, 1.28; 95% CI, 1.09-1.50), region reported as the mid-Atlantic (OR, 1.41; 95% CI, 1.12-1.78) or southern states (OR, 1.47; 95% CI, 1.22-1.70), mothers with a previous child (OR, 1.68; 95% CI, 1.43-1.97), and infants younger than 8 weeks (OR, 0.63; 95% CI, 0.46-0.85). Infants aged 8 to 15 weeks were significantly more likely to be placed nonprone over time compared with the other age groups. Most of the risk factors for prone were significantly related in the opposite direction to supine placement. Conclusions.— The prevalence of infants placed in the prone sleep position declined by 66% between 1992 and 1996. Although causality cannot be proved, SIDS rates declined approximately 38% during this period. To achieve further reduction in prone sleeping, efforts to promote the supine sleep position should be aimed at groups at high risk for prone placement.      

Effects of Computer-Based Clinical Decision Support Systems on Physician Performance and Patient Outcomes: A Systematic Review

Context.— Many computer software developers and vendors claim that their systems can directly improve clinical decisions. As for other health care interventions, such claims should be based on careful trials that assess their effects on clinical performance and, preferably, patient outcomes. Objective.— To systematically review controlled clinical trials assessing the effects of computer-based clinical decision support systems (CDSSs) on physician performance and patient outcomes. Data Sources.— We updated earlier reviews covering 1974 to 1992 by searching the MEDLINE, EMBASE, INSPEC, SCISEARCH, and the Cochrane Library bibliographic databases from 1992 to March 1998. Reference lists and conference proceedings were reviewed and evaluators of CDSSs were contacted. Study Selection.— Studies were included if they involved the use of a CDSS in a clinical setting by a health care practitioner and assessed the effects of the system prospectively with a concurrent control. Data Extraction.— The validity of each relevant study (scored from 0-10) was evaluated in duplicate. Data on setting, subjects, computer systems, and outcomes were abstracted and a power analysis was done on studies with negative findings. Data Synthesis.— A total of 68 controlled trials met our criteria, 40 of which were published since 1992. Quality scores ranged from 2 to10, with more recent trials rating higher (mean, 7.7) than earlier studies (mean, 6.4) (P<.001). Effects on physician performance were assessed in 65 studies and 43 found a benefit (66%). These included 9 of 15 studies on drug dosing systems, 1 of 5 studies on diagnostic aids, 14 of 19 preventive care systems, and 19 of 26 studies evaluating CDSSs for other medical care. Six of 14 studies assessing patient outcomes found a benefit. Of the remaining 8 studies, only 3 had a power of greater than 80% to detect a clinically important effect. Conclusions.— Published studies of CDSSs are increasing rapidly, and their quality is improving. The CDSSs can enhance clinical performance for drug dosing, preventive care, and other aspects of medical care, but not convincingly for diagnosis. The effects of CDSSs on patient outcomes have been insufficiently studied.      

Prevalence and Predictors of the Prone Sleep Position Among Inner-city Infants

Context.— The prone sleep position is associated with an increased risk of sudden infant death syndrome (SIDS), but few studies have assessed factors associated with the choice of infant sleep position. Objectives.— To describe infant sleep position in a cohort of infants born to predominantly low-income, inner-city mothers and to identify predictors of the prone sleep position in this population. Design.— Prospective birth cohort study. Patients and Setting.— Three hundred ninety-four mother-infant dyads, systematically selected from 3 District of Columbia hospitals between August 1995 and September 1996. Mothers were interviewed shortly after delivery and again at 3 to 7 months postpartum. Main Outcome Measures.— Position in which infants were placed for sleep on the night prior to the 3- to 7-month interview. Results.— At 3 to 7 months of age, 157 infants (40%) were placed for sleep in the prone position. Independent predictors of prone sleep position included poverty (odds ratio [OR], 1.81; 95% confidence interval [CI], 1.10-2.99), black race (OR, 2.06; 95% CI, 1.05-4.04), presence of infant's grandmother in the home (OR, 1.83; 95% CI, 1.11-3.00), and intent, as measured shortly after delivery, to place the infant in the prone position (OR, 2.28; 95% CI, 1.44-3.60). Importantly, of the 43 mothers who observed their infants in the prone sleep position while in the hospital, 40 (93%) intended to place their infants prone at home. Conclusions.— A substantial proportion of infants in this predominantly low-income population were placed in the prone sleep position. Educational efforts should address both initial intentions and reinforcement of the correct sleep position, once initiated. Hospitals should ensure that healthy newborn infants are placed in the supine sleep position during the postpartum hospital stay.      

Improving the use of hospice services in nursing homes: a randomized controlled trial

Context  Hospice care may improve the quality of end-of-life care for nursing home residents, but hospice is underutilized by this population, at least in part because physicians are not aware of their patients’ preferences. Objective  To determine whether it is possible to increase hospice utilization and improve the quality of end-of-life care by identifying residents whose goals and preferences are consistent with hospice care. Design, Setting, and Participants  Randomized controlled trial (December 2003-December 2004) of nursing home residents and their surrogate decision makers (N=205) in 3 US nursing homes. Intervention  A structured interview identified residents whose goals for care, treatment preferences, and palliative care needs made them appropriate for hospice care. These residents’ physicians were notified and asked to authorize a hospice informational visit. Main Outcome Measures  The primary outcome measures were (1) hospice enrollment within 30 days of the intervention and (2) families’ ratings of the quality of care for residents who died during the 6-month follow-up period. Results  Of the 205 residents in the study sample, 107 were randomly assigned to receive the intervention, and 98 received usual care. Intervention residents were more likely than usual care residents to enroll in hospice within 30 days (21/107 [20%] vs 1/98 [1%]; P<.001 [Fisher exact test]) and to enroll in hospice during the follow-up period (27/207 [25%] vs 6/98 [6%]; P<.001). Intervention residents had fewer acute care admissions (mean: 0.28 vs 0.49; P = .04 [Wilcoxon rank sum test]) and spent fewer days in an acute care setting (mean: 1.2 vs 3.0; P = .03 [Wilcoxon rank sum test]). Families of intervention residents rated the resident’s care more highly than did families of usual care residents (mean on a scale of 1-5: 4.1 vs 2.5; P = .04 [Wilcoxon rank sum test]). Conclusion  A simple communication intervention can increase rates of hospice referrals and families’ ratings of end-of-life care and may also decrease utilization of acute care resources.      

Estrogen Therapy in Postmenopausal Women: Effects on Cognitive Function and Dementia

Context.— Several studies have suggested that estrogen replacement therapy in postmenopausal women improves cognition, prevents development of dementia, and improves the severity of dementia, while other studies have not found a benefit of estrogen use. Objective.— To determine whether postmenopausal estrogen therapy improves cognition, prevents development of dementia, or improves dementia severity. Data Sources.— We performed a literature search of studies published from January 1966 through June 1997, using MEDLINE, manually searched bibliographies of articles identified, and consulted experts. Study Selection.— Studies that evaluated biological mechanisms of estrogen's effect on the central nervous system and studies that addressed the effect of estrogen on cognitive function or on dementia. Data Extraction.— We reviewed studies for methods, sources of bias, and outcomes and performed a meta-analysis of the 10 studies of postmenopausal estrogen use and risk of dementia using standard meta-analytic methods. Data Synthesis.— Biochemical and neurophysiologic studies suggest several mechanisms by which estrogen may affect cognition: promotion of cholinergic and serotonergic activity in specific brain regions, maintenance of neural circuitry, favorable lipoprotein alterations, and prevention of cerebral ischemia. Five observational studies and 8 trials have addressed the effect of estrogen on cognitive function in nondemented postmenopausal women. Cognition seems to improve in perimenopausal women, possibly because menopausal symptoms improve, but there is no clear benefit in asymptomatic women. Ten observational studies have measured the effect of postmenopausal estrogen use on risk of developing dementia. Meta-analysis of these studies suggests a 29% decreased risk of developing dementia among estrogen users, but the findings of the studies are heterogeneous. Four trials of estrogen therapy in women with Alzheimer disease have been conducted and have had primarily positive results, but most have been small, of short duration, nonrandomized, and uncontrolled. Conclusions.— There are plausible biological mechanisms by which estrogen might lead to improved cognition, reduced risk for dementia, or improvement in the severity of dementia. Studies conducted in women, however, have substantial methodologic problems and have produced conflicting results. Large placebo-controlled trials are required to address estrogen's role in prevention and treatment of Alzheimer disease and other dementias. Given the known risks of estrogen therapy, we do not recommend estrogen for the prevention or treatment of Alzheimer disease or other dementias until adequate trials have been completed.      

Total Parenteral Nutrition in the Critically Ill Patient: A Meta-analysis

Context.— Nutritional support has become a standard of care for hospitalized patients, but whether total parenteral nutrition (TPN) affects morbidity and mortality is unclear. Objective.— To examine the relationship between TPN and complication and mortality rates in critically ill patients. Data Sources.— Computerized search of published research on MEDLINE from 1980 to 1998, personal files, and review of relevant reference lists. Study Selection.— We reviewed 210 titles, abstracts, and papers. Primary studies were included if they were randomized clinical trials of critically ill or surgical patients that evaluated the effect of TPN (compared with standard care) on complication and mortality rates. We excluded studies comparing TPN with enteral nutrition. Data Extraction.— Relevant data were abstracted on the methodology and outcomes of primary studies. Data were abstracted in duplicate, independently. Data Synthesis.— There were 26 randomized trials of 2211 patients comparing the use of TPN with standard care (usual oral diet plus intravenous dextrose) in surgical and critically ill patients. When the results of these trials were aggregated, TPN had no effect on mortality (risk ratio [RR], 1.03; 95% confidence interval [CI], 0.81-1.31). Patients who received TPN tended to have a lower complication rate, but this result was not statistically significant (RR, 0.84; 95% CI, 0.64-1.09). We examined several a priori hypotheses and found that studies including only malnourished patients were associated with lower complication rates but no difference in mortality when compared with studies of nonmalnourished patients. Studies published since 1989 and studies with a higher methods score showed no treatment effect, while studies published in 1988 or before and studies with a lower methods score demonstrated a significant treatment effect. Complication rates were lower in studies that did not use lipids; however, there was no difference in mortality rates between studies that did not use lipids and those studies that did. Studies limited to critically ill patients demonstrated a significant increase in complication and mortality rates compared with studies of surgical patients. Conclusions.— Total parenteral nutrition does not influence the overall mortality rate of surgical or critically ill patients. It may reduce the complication rate, especially in malnourished patients, but study results are influenced by patient population, use of lipids, methodological quality, and year of publication.