Cost-effectiveness analysis: an introductory guide for clinicians.

Economic analyses are becoming increasingly prevalent in the obstetrics and gynecology literature, and it is essential that clinicians have a basic comprehension of this research methodology. The purpose of this article is to provide an introduction to economic analysis, in particular cost-effectiveness analysis, and to summarize the basic principles and recently proposed standards for studies using these analytic methods. The fundamental principle of economic analysis is that choices will have to be made between alternative use of resources because there are not unlimited resources to provide all the medical care possible to each individual. These analyses can illustrate the tradeoffs involved in choosing among a variety of clinical interventions to improve health care, and ultimately inform decision making. With a basic understanding of the key concepts of economic analyses, clinicians and health service researchers will be better prepared to critically review these analyses and incorporate them into daily practice. TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians. LEARNING OBJECTIVES: After completion of this article, the reader will be able to provide an introduction to economic analysis and to summarize the various types of economic analyses, to understand the principle assumption of each analysis and their limitations and to be aware of the various principles of conducting cost-effective analyses.     

Electronic fetal monitoring as a public health screening program: the arithmetic of failure

Electronic fetal monitoring has failed as a public health screening program. Nevertheless, most of the four million low-risk women giving birth in the United States each year continue to undergo this screening. The failure of this program should have been anticipated and thus avoided had the accepted principles of screening been considered before its introduction. All screening tests have poor positive predictive value when searching for rare conditions such as fetal death in labor or cerebral palsy. This problem is aggravated when the screening test does not have good validity as is the case with electronic fetal monitoring. Because of low-prevalence target conditions and mediocre validity, the positive predictive value of electronic fetal monitoring for fetal death in labor or cerebral palsy is near zero. Stated alternatively, almost every positive test result is wrong. To avoid such costly errors in the future, the prerequisites for any screening program must be fulfilled before the program is begun.     

Factors associated with increased charges for hysterectomy

OBJECTIVE: To evaluate factors associated with increased hospital charges for hysterectomy with specific attention to differences based on surgical approach. METHODS: We performed a retrospective cohort study of 686 patients who underwent hysterectomy between January 1997 and September 1997 using medical chart review and hospital financial information. Demographic information, surgical approach (abdominal, vaginal, or laparoscopic), and surgical and postoperative factors were extracted from the medical record. Hospital charges were obtained from the hospital billing database. Relationships between charges and various clinical and demographic variables were examined using chi(2), Fisher exact test, t tests, or analysis of variance, where appropriate. Logistic regression was used to estimate odds ratios while controlling for important confounding variables. RESULTS: In our logistic regression model, blood loss greater than 1,000 mL (odds ratio [OR] 11.8, 95% confidence interval [CI] 4.2-33.2) and operative time 105 minutes or more (OR 14.2, CI 5.8-34.5) were strongly associated with higher charges for hysterectomy. Other factors associated with higher charges included: postoperative fever (OR 2.2, CI 1.1-4.5), increasing length of hospitalization (OR 5.3, CI 3.7-7.7), the use of prophylactic antibiotics (OR 3.0, CI 1.3-6.6), and the laparoscopic surgical approach compared with vaginal hysterectomy (OR 2.7, CI 1.0-7.0). CONCLUSION: Surgical factors such as operative time and blood loss were strongly associated with increased hospital charges for hysterectomy.     

Predictors of chronic pelvic pain in an urban population of women with symptoms and signs of pelvic inflammatory disease

OBJECTIVE: The objective of this study was to assess the risk profile for chronic pelvic pain (CPP) after pelvic inflammatory disease (PID). STUDY: Multivariate logistic regression was used to assess risk factors for CPP in a longitudinal study of 780 predominately black, urban women with clinically suspected PID: complaints of acute pain (<30 days); a clinical finding of pelvic tenderness; and leukorrhea, mucopurulent cervicitis, or untreated gonococcal or chlamydial cervicitis. CPP was defined as pain reported at >or=2 consecutive interviews conducted every 3 to 4 months for 2 to 5 years. RESULTS: Nonblack race (odds ratio [OR], 2.17; 95% confidence interval [CI], 1.31-3.58), being married (OR, 2.06; 95% CI, 1.02-4.18), a low SF-36 mental health composite score (OR, 2.71; 95% CI, 1.69-4.34), >or=2 prior PID episodes (OR, 2.84; 95% CI, 1.07-7.54), and smoking (OR, 1.65; 95% CI, 1.01-2.71) independently predicted CPP. Histologic endometritis or evidence of endometrial Neisseria gonorrhoeae or Chlamydia trachomatis infection was negatively associated with CPP (OR, 0.69; 95% CI, 0.44-1.10). CONCLUSIONS: A range of demographic, clinical, historical, and behavioral factors predict CPP after PID.     

Randomization in controlled clinical trials: why the flip of a coin is so important

The randomized controlled trial (RCT) is considered the highest level of medical evidence. In this brief overview, we discuss several key principles of the RCT. First, balance is paramount. Comparison groups must have similar proportions of participants with "important" prognostic and confounding factors. Randomization may or may not achieve this balance; if it does not, statistical adjustments should be used. Second, a statistical analysis should emphasize comparability and not mask dissimilarity. If the trial was indeed randomized, certain analysis techniques, such as an intention to treat analysis, should always be presented. Third, additional bias-reducing techniques, such as concealing treatment assignments from treating physicians and participants (i.e., masking) and using clearly defined exclusion and inclusion criteria, should be used wherever possible.     

The effect of prematurity on vaginal birth after cesarean delivery: success and maternal morbidity

OBJECTIVE: We sought to compare vaginal birth after cesarean (VBAC) success and uterine rupture rates between preterm and term gestations in women with a history of one prior cesarean delivery. Our hypothesis was that preterm women undergoing VBAC were more likely to be successful and have a lower rate of complications than term women undergoing VBAC. METHODS: We reviewed medical records of women with a history of a cesarean delivery who either attempted a VBAC or underwent a repeat cesarean delivery from 1995 through 2000 in 17 community and university hospitals. We collected information on demographics, medical and obstetric history, complications, and outcome of the index pregnancy. The primary analysis was limited to women with singleton gestations and one prior cesarean delivery. Statistical analysis consisted of bivariate and multivariable techniques. RESULTS: Among the 20,156 patients with one prior cesarean delivery, 12,463 (61%) attempted a VBAC. Mean gestational ages for the term and preterm women were 39.2 weeks and 33.9 weeks of gestation, respectively. The VBAC success rates for the term and preterm groups were 74% and 82%, respectively (P < .001). Multivariable analysis showed that the VBAC success was higher (adjusted odds ratio 1.54, 95% confidence interval 1.27-1.86) in preterm gestations. A decreased risk of rupture among preterm gestations was suggested in these results (adjusted odds ratio 0.28, 95% confidence interval 0.07-1.17; P = .08). CONCLUSION: Preterm patients undergoing a VBAC have higher success rates when compared with term patients undergoing a VBAC. Preterm patients undergoing VBAC may have lower uterine rupture rates.     

Improving birth control service utilization by offering services prerelease vs postincarceration

OBJECTIVES: We examined whether incarcerated women would substantially increase birth control initiation if contraceptive services were available within the prison compared with after their release back into the community. METHODS: During phase 1 of the study, a nurse educator met with women at the Rhode Island Adult Correctional Institute and offered them referrals for contraceptive services at a community health clinic after their release. During phase 2, contraceptive services were offered to women during their incarceration. RESULTS: The majority of the participants (77.5%) reported a desire to initiate use of birth control methods. Within 4 weeks of their release, 4.4% of phase 1 participants initiated use of a contraceptive method, compared with 39.1% of phase 2 participants (odds ratio [OR]=14.6; 95% confidence interval [CI]=5.5, 38.8). CONCLUSIONS: Provision of contraceptive services to women during their incarceration is feasible and greatly increases birth control initiation compared to providing services only in the community.     

Efficacy of clindamycin vaginal ovule (3-day treatment) vs. clindamycin vaginal cream (7-day treatment) in bacterial vaginosis

OBJECTIVE: To compare the efficacy and safety of a 3-day regimen of clindamycin vaginal ovules with a 7-day regimen of clindamycin vaginal cream for the treatment of bacterial vaginosis (BV). METHODS: Women with a clinical diagnosis of BV were treated with a 3-day course of clindamycin ovules or a 7-day course of clindamycin cream administered intravaginally. Three hundred and eighty-four patients received study drug and were included in the evaluable patient population (ovule group, n = 204; cream group, n = 180). Assessments included pelvic examination and diagnostic testing. Primary efficacy endpoints were a resolution of two of three diagnostic criteria at the first follow-up visit and three of three diagnostic criteria at the second. RESULTS: Cure rates in the evaluable patient population were similar between treatment groups: 53.7% (109/204) for the ovule group and 47.8% (85/180) for the cream group (p = 0.2471, 95% CI -4.1-16.0%). The most commonly reported medical event, vulvovaginal pruritus, had similar incidence in both treatment groups. CONCLUSIONS: A 3-day course of clindamycin vaginal ovules is as effective and well-tolerated as a 7-day course of clindamycin vaginal cream in the treatment of BV.