A pilot randomized, controlled trial of an in-home drinking water intervention among HIV + persons

Although immunocompromised persons may be at increased risk for gastrointestinal illnesses, no trials investigating drinking water treatment and gastrointestinal illness in such patients have been published. Earlier results from San Francisco suggested an association (OR 6.76) between tap water and cryptosporidiosis among HIV + persons. The authors conducted a randomized, triple-blinded intervention trial of home water treatment in San Francisco, California, from April 2000 to May 2001. Fifty HIV-positive patients were randomized to externally identical active (N = 24) or sham (N = 26) treatment devices. The active device contained a filter and UV light; the sham provided no treatment. Forty-five (90%) of the participants completed the study and were successfully blinded. Illness was measured using 'highly credible gastrointestinal illness' (HCGI), a previously published measure. There were 31 episodes of HCGI during 1,797 person-days in the sham group and 16 episodes during 1,478 person-days in the active group. The adjusted relative risk was 3.34 (95% CI: 0.99-11.21) times greater in those with the sham device. The magnitude of the point estimate of the risk, its consistency with recently published observational data, and its relevance for drinking water choices by immunocompromised individuals support the need for larger trials.     

The Sonoma Water Evaluation Trial: A Randomized Drinking Water Intervention Trial to Reduce Gastrointestinal Illness in Older Adults

Objectives. We estimated the relative rate of highly credible gastrointestinal illness (HCGI) per year associated with active versus sham household water filtration devices among older adults in a community receiving tap water meeting current US standards.Methods. We conducted a randomized, triple-blinded, crossover trial in 714 households (988 individuals), which used active and sham water filtration devices for 6 months each. We estimated the annual incidence rate ratio of HCGI episodes and the longitudinal prevalence ratio of HCGI days at population and individual levels with a generalized estimating equation (GEE) and generalized linear mixed models (GLMMs), respectively, adjusted for covariates associated with outcome.Results. The incidence rate ratios (active versus sham) were 0.88 (95% confidence interval [CI] = 0.77, 1.00) and 0.85 (95% CI = 0.76, 0.94) HCGI episodes per year estimated by GEE and GLMM models, respectively. The corresponding longitudinal prevalence ratios were 0.88 (95% CI = 0.74, 1.05) and 0.84 (95% CI = 0.78, 0.90) HCGI days per person per year.Conclusions. We observed reductions in population- and individual-level measures of HCGI associated with use of the active filtration device. These findings suggest the need for further research on the impact of drinking water on the health of sensitive subpopulations.Widespread outbreaks of gastrointestinal infectious illness have occurred in the United States at times when public water treatment systems have failed.^1,2 This has led to intense public interest in whether the microbial content of drinking water might present a health risk even when public water treatment systems are believed to be functioning properly.^3–5Several randomized intervention trials with supplemental in-home drinking water treatment have been reported in general populations^6–10; none focused on older individuals. Estimates of the annual number of cases of acute gastrointestinal illness related to drinking water in the United States, drawn from a variety of data sources and study designs, vary from 1.8 million to 16.4 million cases per year in the general population.^11–13 The US Environmental Protection Agency has called attention to the differential burden of drinking water–related disease among those who may be at increased risk of infection and serious illness from exposure to microbial pathogens, such as the elderly, children, and persons who are immunocompromised by infection, malignancy, or chemotherapy.^14–16 Older adults may be particularly susceptible to gastrointestinal infections and to severe illness once infected.^17–19We conducted the first drinking water trial exclusively studying older adults (aged ≥ 55 years). The study, performed in Sonoma County, California, was a randomized, controlled, triple-blinded (participants, investigators, analysts), crossover intervention trial. Our goal was to estimate the efficacy of an in-home water filter to reduce the risk of highly credible gastrointestinal illness (HCGI) among older adults living in a community whose tap water met or exceeded current US drinking water standards.     

Placebo surgery research: a blinding imperative

In placebo surgery research, intervention group subjects receive a real surgical procedure, and control subjects receive a sham surgical procedure. The sham procedure is designed to recapitulate enough of the real procedure to blind participants to group assignment. Placebo surgery designs are used to control for placebo effects, and to eliminate the bias that might result if participants and investigators were aware of group assignment when outcomes are measured. In placebo surgery studies, in which participants are placed at increased risk to achieve the scientific validity provided by blinding, it is imperative that the blind be maintained, and maintainable, to justify putting subjects at risk to achieve it. In circumstances in which the outcome assessors are not fully blinded, or in which the intervention is not amenable to rigorous blinding, placebo surgery studies are not ethical. Investigators doing placebo surgery trials should obtain data on the integrity of the blind from both subjects and outcome assessors, to inform the validity of the results and to provide input for "blindability" decisions involving future trials.     

Inferences drawn from a risk assessment compared directly with a randomized trial of a home drinking water intervention

Risk assessments and intervention trials have been used by the U.S. Environmental Protection Agency to estimate drinking water health risks. Seldom are both methods used concurrently. Between 2001 and 2003, illness data from a trial were collected simultaneously with exposure data, providing a unique opportunity to compare direct risk estimates of waterborne disease from the intervention trial with indirect estimates from a risk assessment. Comparing the group with water treatment (active) with that without water treatment (sham), the estimated annual attributable disease rate (cases per 10,000 persons per year) from the trial provided no evidence of a significantly elevated drinking water risk [attributable risk=-365 cases/year, sham minus active; 95% confidence interval (CI) , -2,555 to 1,825]. The predicted mean rate of disease per 10,000 persons per person-year from the risk assessment was 13.9 (2.5, 97.5 percentiles: 1.6, 37.7) assuming 4 log removal due to viral disinfection and 5.5 (2.5, 97.5 percentiles: 1.4, 19.2) assuming 6 log removal. Risk assessments are important under conditions of low risk when estimates are difficult to attain from trials. In particular, this assessment pointed toward the importance of attaining site-specific treatment data and the clear need for a better understanding of viral removal by disinfection. Trials provide direct risk estimates, and the upper confidence limit estimates, even if not statistically significant, are informative about possible upper estimates of likely risk. These differences suggest that conclusions about waterborne disease risk may be strengthened by the joint use of these two approaches. Key words: drinking water, gastrointestinal, intervention trial, microbial risk assessment, waterborne pathogens.     

The risk of unblinding was infrequently and incompletely reported in 300 randomized clinical trial publications

ObjectivesTo assess the proportion of clinical trials explicitly reporting the risk of unblinding, to evaluate the completeness of reporting on unblinding risk, and to describe the reported procedures involved in assessing unblinding.Study Design and SettingWe sampled at random 300 blinded randomized clinical trials indexed in PubMed in 2010. Two authors read the trial publications and extracted data independently.ResultsTwenty-four trial publications, or 8% (95% confidence interval [CI], 5, 12%), explicitly reported the risk of unblinding, of which 16 publications, or 5% (95% CI, 3, 8%), reported compromised blinding; and 8 publications, or 3% (95% CI, 1, 5%), intact blinding. The reporting on risk of unblinding in the 24 trial publications was generally incomplete. The median proportion of assessments per trial affected by unblinding was 3% (range 1–30%). The most common mechanism for unblinding was perceptible physical properties of the treatments, for example, a difference in the taste and odor of a typhoid vaccine compared with its placebo.ConclusionPublished articles on randomized clinical trials infrequently reported risk of unblinding. This may reflect a tendency for avoiding reporting actual or suspected unblinding or a genuine low risk of unblinding.     

Prevention of upper respiratory tract infections by gargling: a randomized trial

BACKGROUND: Gargling to wash the throat is commonly performed in Japan, and people believe that such hygienic routine, especially with gargle medicine, prevents upper respiratory tract infections (URTIs). Its effectiveness, however, has not been established by clinical trials. DESIGN: Randomized controlled trial carried out in 2002-2003 winter season and analyzed in 2003 and 2004. PARTICIPANTS: Healthy volunteers (387) aged 18 to 65 years. INTERVENTION: Participants were randomly assigned to water gargling, povidone-iodine gargling, and usual care (control). Subjects in the two gargling groups were requested to gargle with water or diluted povidone-iodine at least three times a day. Participants were followed for 60 days. MAIN OUTCOME MEASURES: The primary outcome measure was first URTI incidence. Severity of URTI symptoms among incident cases was also evaluated. Both outcomes were assessed with a self-administered symptom record. Analyses were performed on an intention-to-treat basis. RESULTS: A total of 130 participants contracted URTIs. The incidence rate of first URTI was 0.26 episodes/30 person-days among control subjects. The rate decreased to 0.17 episodes/30 person-days in the water gargling group, and 0.24 episodes/30 person-days in the povidone-iodine gargling group. Respective incidence rate ratios against controls were 0.64 (95% confidence interval [CI]=0.41-0.99) and 0.89 (95% CI=0.60-1.33). A Cox regression (proportional hazard model) revealed the efficacy of water gargling (hazard ratio=0.60, 95% CI=0.39-0.95). Even when a URTI occurred, water gargling tended to attenuate bronchial symptoms (p=0.055). CONCLUSIONS: Simple water gargling was effective to prevent URTIs among healthy people. This virtually cost-free modality would appreciably benefit the general population.     

A randomized, blinded, controlled trial investigating the gastrointestinal health effects of drinking water quality

A double-blinded, randomized, controlled trial was carried out in in Melbourne, Australia, to determine the contribution of drinking water to gastroenteritis. Melbourne is one of the few major cities in the world that draws drinking water from a protected forest catchment with minimal water treatment (chlorination only). Six hundred families were randomly allocated to receive either real or sham water treatment units (WTUs) installed in their kitchen. Real units were designed to remove viruses, bacteria, and protozoa. Study participants completed a weekly health diary reporting gastrointestinal symptoms during the 68-week observation period. There were 2,669 cases of highly credible gastroenteritis (HCG) during the study (0.80 cases/person/year). The ratio of HCG episode rates for the real WTU group compared to the sham WTU group was 0.99 (95% confidence interval, 0.85-1.15, p = 0.85). We collected 795 fecal specimens from participants with gastroenteritis, and pathogens were not more significantly common in the sham WTU group. We found no evidence of waterborne disease in Melbourne. The application of this methodology to other water supplies will provide a better understanding of the relationship between human health and water quality.     

Placebo effects and the common cold: a randomized controlled trial

PURPOSE We wanted to determine whether the severity and duration of illness caused by the common cold are influenced by randomized assignment to open-label pills, compared with conventional double-blind allocation to active and placebo pills, compared with no pills at all.METHODS We undertook a randomized controlled trial among a population with new-onset common cold. Study participants were allocated to 4 parallel groups: (1) those receiving no pills, (2) those blinded to placebo, (3) those blinded to echinacea, and (4) those given open-label echinacea. Primary outcomes were illness duration and area-under-the-curve global severity. Secondary outcomes included neutrophil count and interleukin 8 levels from nasal wash at intake and 2 days later.RESULTS Of 719 randomized study participants, 2 were lost and 4 exited early. Participants were 64% female, 88% white, and aged 12 to 80 years. Mean illness duration for each group was 7.03 days for those in the no-pill group, 6.87 days for those blinded to placebo, 6.34 days for those blinded to echinacea, and 6.76 days for those in the open-label echinacea group. Mean global severity scores for the 4 groups were no pills, 286; blinded to placebo, 264; blinded to echinacea, 236; and open-label echinacea, 258. Between-group differences were not statistically significant. Comparing the no-pill with blinded to placebo groups, differences (95% confidence interval [CI]) were −0.16 days (95% CI, −0.90 to 0.58 days) for illness duration and −22 severity points (95% CI, −70 to 26 points) for global severity. Comparing the group blinded to echinacea with the open-label echinacea group, differences were 0.42 days (95% CI, −0.28 to 1.12 days) and 22 severity points (95% CI, −19 to 63 points). Median change in interleukin 8 concentration and neutrophil cell count, respectively by group, were 30 pg/mL and 1 cell for the no-pill group, 39 pg/mL and 1 cell for the group binded to placebo, 58 pg/mL and 2 cells for the group blinded to echinacea, and 70 pg/mL and 1 cell for the group with open-label echinacea, also not statistically significant. Among the 120 participants who at intake rated echinacea’s effectiveness as greater than 50 on a 100-point scale for which 100 is extremely effective, illness duration was 2.58 days shorter (95% CI, −4.47 to −0.68 days) in those blinded to placebo rather than no pill, and mean global severity score was 26% lower but not significantly different (−97.0, 95% CI, −249.8 to 55.8 points). In this subgroup, neither duration nor severity differed significantly between the group blinded to echinacea and the open-label echinacea group.CONCLUSIONS Participants randomized to the no-pill group tended to have longer and more severe illnesses than those who received pills. For the subgroup who believed in echinacea and received pills, illnesses were substantively shorter and less severe, regardless of whether the pills contained echinacea. These findings support the general idea that beliefs and feelings about treatments may be important and perhaps should be taken into consideration when making medical decisions.     

A review of blinding in randomized controlled trials found results inconsistent and questionable

BACKGROUND AND OBJECTIVE: To determine methods to assess the success of blinding in randomized controlled trials (RCTs). METHODS: We searched MEDLINE, the Cochrane Controlled Trials Register, and the Cochrane Method Register and performed a manual search to target studies that attempt to assess blinding and describe the methods used in those studies. RESULTS: A total of 90 reports were selected. Reports assessed the success of blinding participants (n = 58), care providers (n = 36), and outcome assessors (n = 15). Of the 58 reports assessing the success of blinding participants, 54 (93%) reported asking participants to guess their treatment assignment. There was no consistency in timing of assessment (e.g., once at the end of the trial, 57%, or several times during the trial, 26%) or modalities of answering (e.g., "do not know" answers, 43%, or participants forced to guess, 31%). A statistical analysis was performed in 57% of reports. The statistical analysis mainly compared the proportion of correct guesses to those produced by chance (32%) or checked for a relation between participants' guesses and treatment assignment (23%). CONCLUSIONS: Methods of assessing the success of blinding, analysis and reporting the results were inconsistent and questionable.     

A systematic review and meta-analysis of the cardioprotective effects of remote ischaemic preconditioning in open cardiac surgery

Objective

To investigate the cardioprotective efficacy of remote ischaemic preconditioning (RIPC) in cardiac surgery.

Design

We have performed a systematic search of MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials to identify randomized controlled trials involving RIPC.

Setting

Randomized controlled trials of RIPC in open cardiac surgery patients.

Main outcome measures

Meta-analysis was performed with the primary outcome the standardized mean difference between intervention and control groups in 12 hour postoperative troponin concentration. Heterogeneity was examined by fixed effects meta-regression.

Results

Ten studies with a total of 693 participants were included in the meta-analysis. RIPC reduced troponin levels 12 hours after surgery compared with control. The fixed and random effects differences were 0.35 (95% CI 0.19 to 0.51) and 0.53 (95% CI 0.18-0.88) respectively. However, important heterogeneity was present. Fixed effects meta-regression partially accounted for heterogeneity based on whether studies had full blinding, comprising blinding of patients, surgeons, anaesthetists and investigators. Studies with incomplete or no blinding demonstrated a larger estimate of effect, 0.74 (95% CI 0.47 to 1.00) compared to those with full blinding, 0.13 (95% CI - 0.07 to 0.33).

Conclusions

Although our analysis suggests RIPC may result in cardiac protection during cardiac surgery, the effect was most marked in studies without full blinding, with a smaller and statistically non-significant effect in fully blinded studies. We propose that further double blind randomized controlled trials investigating the cardioprotective effects of RIPC in cardiac surgery are required to resolve the current clinical uncertainty.     

Effect of calcium supplementation on fracture risk: a double-blind randomized controlled trial

BACKGROUND: The effect of supplementation with calcium alone on risk fractures in a healthy population is not clear. OBJECTIVE: The objective was to determine whether 4 y of calcium supplementation would reduce the fracture risk during treatment and subsequent follow-up in a randomized placebo-controlled trial. DESIGN: The participants were aged <80 y at study entry (mean age: 61 y), were generally healthy, and had a recent diagnosis of colorectal adenoma. A total of 930 participants (72% men; mean age: 61 y) were randomly assigned to receive 4 y of treatment with 3 g CaCO(3) (1200 mg elemental Ca) daily or placebo and were followed for a mean of 10.8 y. The primary outcomes of this analysis were all fractures and minimal trauma fractures (caused by a fall from standing height or lower while sitting, standing, or walking). RESULTS: There were 46 fractures (15 from minimal trauma) in 464 participants in the calcium group and 54 (29 from minimal trauma) in 466 participants in the placebo group. The overall risk of fracture differed significantly between groups during the treatment phase [hazard ratio (HR): 0.28; 95% CI: 0.09, 0.85], but not during the subsequent posttreatment follow-up (HR: 1.10; 95% CI: 0.71, 1.69). Minimal trauma fractures were also less frequent in the calcium group during treatment (HR: 0; 95% CI: 0, 0.50). CONCLUSION: Calcium supplementation reduced the risk of all fractures and of minimal trauma fractures among healthy individuals. The benefit appeared to dissipate after treatment was stopped. This trial was registered at clinicaltrials.gov as NCT00153816.     

Blinding decreased recruitment in a prevention trial of postmenopausal hormone therapy

PURPOSE: To compare the effect of blind design (active drug and placebo) and nonblind design (active drug and no treatment) on recruitment. SETTING: A primary prevention trial with postmenopausal hormone therapy in Estonia. METHODS: Women who were eligible and willing to participate on the basis of the questionnaire survey were randomized into blind and nonblind groups. Recruitment rates are based on record keeping, and reasons for participating were requested in the first-year follow-up. RESULTS: The recruitment was 30% higher in the nonblind group: of the 4,295 women invited, 37% (95% confidence interval CI=35-39%) in the blind group and 48% (95% CI=46-49%) in the nonblind group were recruited. In both groups, once randomized, most of the losses were women who did not attend the first clinical examination: 49% (blind; 95% CI=47-51%) and 40% (nonblind; 95% CI=38-42%). The rest were found ineligible or lost their interest during clinical examinations. The reasons for joining the trial were relatively similar in the two groups. CONCLUSIONS: Blinding decreased women's interest in joining a long-term preventive trial. Women's reasons for joining the trial were not influenced by blinding.     

Unmeasured confounding caused slightly better response to HAART within than outside a randomized controlled trial

OBJECTIVE: To compare the outcome of highly active antiretroviral therapy (HAART) in HIV-infected patients initiating equivalent regimens within and outside a randomized controlled trial (RCT). STUDY DESIGN AND SETTING: The Danish Protease Inhibitor Study (DAPIS) was a national multicenter RCT comparing initial treatment with indinavir, ritonavir, or saquinavir/ritonavir during 96 weeks. From the Danish HIV Cohort Study we identified all patients initiating one of these protease-inhibitor-based HAART regimens: 425 patients within DAPIS and 677 outside the trial. We compared viral load, CD4 count response, and mortality. RESULTS: At weeks 96 and 240, trial participants were more likely than nonparticipants to have undetectable viral load (adjusted odds ratio [adOR] 1.28 [95% CI=0.94-1.74] and 1.70 [95% CI=1.16-2.50]) and a CD4 increase > or =100 cells/microl (adOR 1.37 [95% CI=1.03-1.82] and 1.53 [95% CI=1.04-2.25]). For antiretroviral-experienced, but not for antiretroviral-na?ve patients, trial participants had a lower risk of death (mortality rate ratio [MRR]=0.46 [95% CI=0.27-0.77]) than nonparticipants. This effect was moderated in adjusted analyses (MRR=0.60 [0.33-1.07]). CONCLUSIONS: Compared to nontrial patients, trial participants had better response to HAART. The differences were small defying the notion that results obtained in RCTs are unachievable in routine clinical practice.     

Web-Based Delirium Prevention Application for Long-Term Care Facilities

ObjectiveA web-based application was developed for medical staff to easily access and use a comprehensive delirium prevention management program—comprising risk prediction, assessment, and intervention—even in long-term care facilities with insufficient systems.DesignA randomized control trial.Setting and ParticipantsA long-term care facility with 250 beds in Korea. Participants were 130 facility residents aged 18 or older who understood the purpose of this study and for whom a legal representative provided participation consent. Participants were randomly assigned to the intervention and control groups (n = 65 per group).MethodsThe participants’ risk of delirium episodes was predicted using the web-based application Web_DeliPREVENT_4LCF. Delirium was assessed using the built-in Short Confusion Assessment Method (S-CAM). Among the intervention group, nonpharmacological, multicomponent delirium prevention interventions guided by the application were applied to participants who were predicted to be at risk for delirium or tested positive for delirium. The intervention was provided for 30 days.ResultsThe intervention group had a 0.30 times lower incidence of delirium [95% confidence interval (CI) 0.12–0.79; P = .015] and 0.08 times lower 1-month hospitalization mortality (95% CI 0.01–0.79; P = .031) than the control group. There were no differences between the 2 groups in delirium severity, mortality, and 3-month hospitalization mortality, long-term care facility discharge, and length of stay.Conclusions and ImplicationsThe Web_DeliPREVENT_4LCF was effective in reducing delirium episodes and 1-month in-hospital mortality. Therefore, even in Korean long-term care facilities, which lack manpower and electronic medical record systems compared with general hospitals, the health care professional can easily access and use the app for early detection and preventive intervention for residents’ delirium.RegistrationKCT0005804.     

A new tool for malaria prevention?: Results of a trial of permethrin-impregnated bedsheets (shukas) in an area of unstable transmission

BACKGROUND: Despite gains in malaria control through impregnated treated nets (ITN), malaria remains a major concern. Netting is expensive and impractical for many communities. Here we present the findings of a community-based trial of impregnated bedsheets (shukas) in Kenya. METHODS: A total of 472 individuals were enrolled in a randomized community trial where the unit of randomization was the hamlet (manyatta). Baseline data included socio-demographic data, parasite prevalence data from thick and thin blood smears, and clinical measures of malaria. The intervention involved the dipping of shukas owned by the experimental group in permethrin. FINDINGS: The prevalence of malaria in the study population (based on laboratory results) was considerably lower than that used for the power calculation based on clinical estimates (2.2% versus 20%). For those aged 6 or over, the rate of malaria cases (events per 10 000 person-days at risk) was 1.41 in the experimental group versus 7.49 in the control group (incidence rate ratio 0.187, 95% CI: 0.046- 0.770). For children 相似文献   

Increasing influenza and pneumococcal immunization rates: a randomized controlled study of a senior center-based intervention

BACKGROUND: Immunizations decrease morbidity from influenza and pneumococcal infections. Immunization levels remain below desired levels despite clinic-based and public education efforts. This paper describes a randomized, controlled trial of a senior center-based program, which used peer-to-peer outreach to increase pneumococcal and influenza immunization rates among an urban senior population. METHODS: Seniors were randomized to intervention or control groups. The intervention group received educational brochures mailed with reply cards to report immunization status, telephone calls from senior volunteers to unimmunized participants, and computerized immunization tracking. Immunization rates were obtained before and after the intervention by self-report. RESULTS: Among participants without prior pneumococcal immunization, the pneumococcal immunization rate among the intervention group (52.0%; 95% CI = 46.6%-57.4%) was significantly higher than that of the control group (30.9%; 95% CI = 26.6%-35.2%) (rate ratio = 1.68; 95% CI = 1.40-2.03). Among those without influenza immunization in the prior year, significantly more (50.0%; 95% CI = 40.0%-60.0%) were immunized against influenza in the intervention group than in the control group (23.0%; 95% CI = 15.2%-33.3%) (rate ratio = 2.17; 95% CI = 1.42-3.31). Among those with influenza immunization in the prior year, the rate ratio was 1.04 (95% CI = 1.01-1.07). CONCLUSIONS: The intervention increased both influenza and pneumococcal immunization rates to high levels, suggesting that further progress in increasing adult immunization coverage is possible.     

The association of calcium and vitamin D with risk of colorectal adenomas

The Polyp Prevention Trial (PPT) was a multicenter randomized clinical trial designed to determine the effects of a high-fiber, high-fruit and vegetable, low-fat diet on the recurrence of adenomatous polyps in the large bowel. Detailed dietary intake and supplement use data were collected at baseline and at each of 4 annual study visits. Adenoma recurrence was ascertained by complete colonoscopy at baseline and after 1 and 4 y. Recurrence was found in 754 of the 1905 trial participants. We evaluated the association between calcium and vitamin D intake and adenomatous polyp recurrence after adjusting for intervention group, age, gender, nonsteroidal anti-inflammatory drug use, total energy intake, and the interaction of gender and intervention group. Vitamin D models were also adjusted for the location of the clinic site. Dietary variables were adjusted for total energy intake via the residual method. There were no overall significant associations between adenoma recurrence and dietary calcium intake [odds ratio (OR) for the 5th compared with the lowest quintile = 0.91; 95% CI = 0.67-1.23; P-trend = 0.68], total calcium intake (OR = 0.86; 95% CI = 0.62-1.18; P-trend = 0.20), or dietary vitamin D intake (OR = 0.93; 95% CI = 0.69-1.25; P-trend = 0.43) averaged over follow-up. Total vitamin D intake was weakly inversely associated with adenoma recurrence (OR = 0.84; 95% CI = 0.62-1.13; P-trend = 0.03). Supplemental calcium and vitamin D use during follow-up also were inversely associated with adenoma recurrence (OR for any compared with no use = 0.82; 95% CI = 0.68-0.99; and OR = 0.82; 95% CI = 0.68-0.99; for calcium and vitamin D, respectively). Slightly stronger associations were noted for the prevention of multiple recurrences. Our analyses did not suggest a significant effect modification between total calcium and total vitamin D intake (P = 0.14) on risk for adenoma recurrence. This trial cohort provides some evidence that calcium and vitamin D may be inversely associated with adenoma recurrence.     

An observational study found that authors of randomized controlled trials frequently use concealment of randomization and blinding, despite the failure to report these methods

BACKGROUND AND OBJECTIVE: Readers of randomized controlled trials (RCTs) commonly assume that what was not reported did not occur. We undertook an observational study to determine whether concealment of randomization or blinding was used in RCTs that failed to report these bias-reducing strategies. METHODS: We recorded the reporting of concealment of randomization and blinding in 105 RCTs. We subsequently contacted the authors and determined if they had used these methodological safeguards. RESULTS: We successfully obtained data from 98 authors. The authors in the full-text publications of these 98 RCTs failed to report the presence or absence of concealment of randomization in 55%, and the blinding status of participants in 26%, health care providers in 64%, data collectors in 84%, outcome assessors in 83%, and data analysts in 96%. In direct contact, authors frequently reported concealing randomization (96%; 95% confidence interval CI=87-100%), blinding participants (20%; 95% CI=7-41%), blinding health care providers (65%; 95% CI=52-77%), blinding data collectors (65%; 95% CI=53-75%), blinding outcome assessors (79%; 95% CI=69-87%), and blinding data analysts (50%; 95% CI=40-60%), despite not reporting the use of these methodological safeguards in their publications. CONCLUSIONS: Readers should not assume that bias-reducing procedures not reported in an RCT did not occur.     

Effectiveness of seasonal trivalent influenza vaccination against hospital-attended acute respiratory infections in pregnant women: A retrospective cohort study

BackgroundPregnant women are at risk of serious influenza infection. Although previous studies indicate maternal influenza vaccination can prevent hospitalisation in young infants, there is limited evidence of the effect in mothers.MethodsA cohort of 34,701 pregnant women delivering between 1 April 2012 and 31 December 2013 was created using birth records. Principal diagnosis codes from hospital emergency department (ED) and inpatient records were used to identify episodes of acute respiratory illness (ARI) during the 2012 and 2013 southern hemisphere influenza seasons. Cox regression models were used to calculate adjusted hazard ratios (aHRs) by maternal vaccination status, controlling for Indigenous status, socioeconomic level, medical conditions, and week of delivery.Results3,007 (8.7%) women received a seasonal influenza vaccine during pregnancy. Vaccinated women were less likely to visit an ED during pregnancy for an ARI (9.7 visits per 10,000 person-days vs. 35.5 visits per 10,000 person-days; aHR: 0.19, 95% CI: 0.05−0.68). Vaccinated women were also less likely to be hospitalised with an ARI compared to unvaccinated women (16.2 hospitalisations per 10,000 person-days vs. 34.0 hospitalisations per 10,000 person-days; aHR: 0.35, 95% CI: 0.13−0.97).ConclusionsInfluenza vaccination during pregnancy was associated with significantly fewer hospital attendances for ARI in pregnant women.