Impact of Selection Bias on Treatment Effect Size Estimates in Randomized Trials of Oral Health Interventions: A Meta-epidemiological Study.

Emerging evidence suggests that design flaws of randomized controlled trials can result in over- or underestimation of the treatment effect size (ES). The objective of this study was to examine associations between treatment ES estimates and adequacy of sequence generation, allocation concealment, and baseline comparability among a sample of oral health randomized controlled trials. For our analysis, we selected all meta-analyses that included a minimum of 5 oral health randomized controlled trials and used continuous outcomes. We extracted data, in duplicate, related to items of selection bias (sequence generation, allocation concealment, and baseline comparability) in the Cochrane Risk of Bias tool. Using a 2-level meta-meta-analytic approach with a random effects model to allow for intra- and inter-meta-analysis heterogeneity, we quantified the impact of selection bias on the magnitude of ES estimates. We identified 64 meta-analyses, including 540 randomized controlled trials analyzing 137,957 patients. Sequence generation was judged to be adequate (at low risk of bias) in 32% ( n = 173) of trials, and baseline comparability was judged to be adequate in 77.8% of trials. Allocation concealment was unclear in the majority of trials ( n = 458, 84.8%). We identified significantly larger treatment ES estimates in trials that had inadequate/unknown sequence generation (difference in ES = 0.13; 95% CI: 0.01 to 0.25) and inadequate/unknown allocation concealment (difference in ES = 0.15; 95% CI: 0.02 to 0.27). In contrast, baseline imbalance (difference in ES = 0.01, 95% CI: -0.09 to 0.12) was not associated with inflated or underestimated ES. In conclusion, treatment ES estimates were 0.13 and 0.15 larger in trials with inadequate/unknown sequence generation and inadequate/unknown allocation concealment, respectively. Therefore, authors of systematic reviews using oral health randomized controlled trials should perform sensitivity analyses based on the adequacy of sequence generation and allocation concealment.

Association between sleep apnea and low bone mass in adults: a systematic review and meta-analysis.

We performed a systematic review of the literature to assess the association between sleep apnea and bone metabolism diseases including osteoporosis in adult population. Results from clinical trials suggest that the association between sleep apnea and low bone mass in adults is possible. INTRODUCTION: This study aimed to synthesize existing evidence on the potential association between sleep apnea and low bone mass in adults. METHODS: Electronic searches of five databases were performed. The inclusion criteria consisted of studies in humans that assessed potential associations between sleep apnea and bone metabolic diseases in an adult population. For diagnosis of sleep apnea overnight polysomnography, home polygraphy, or validated records from healthcare databases were considered. Reduced bone density, osteoporosis, serum/urinary levels for markers of bone formation and resorption, or risk of fractures caused without history of trauma were considered indicators of low bone mass. A random-effects model meta-analysis was applied when possible. RESULTS: Of the 963 relevant references, 12 studies met our inclusion criteria and were assessed to be of medium to low bias. Nine out of 12 studies reported an association between sleep apnea and low bone mass (increased bone resorption markers, reduced bone density, and higher risk of osteoporosis). Two studies did not report a significant association, whereas one study reported an increase of bone density in sleep apnea patients compared to non-sleep apnea patients. Meta-analysis of 2 studies (n = 112,258 patients) showed that sleep apnea was a significant risk factor for osteoporosis (odds ratio (OR), 1.92; 95%CI, 1.24 to 2.97; I2 = 66%); females only had an OR of 2.56 (95% CI, 1.96 to 3.34; I2 = 0%) while the OR in males was 2.03 (95% CI, 1.24 to 3.35; I2 = 38%). CONCLUSIONS: An association between sleep apnea and low bone mass in adults is plausible, but supporting evidence has a risk of bias and is inconsistent.

Adolescent patients' experience with the Carriere distalizer appliance.

AIM: To examine adolescent patients' experience with the Carriere Distalizer Appliance (CDA) and compare it with that of the Forsus Fatigue Resistant Device (FFRD). MATERIALS AND METHODS: A survey was administered to 42 patients treated with the CDA and 70 patients treated with the FFRD. Amount of time required to become accustomed to the appliance, how many patients experienced side effects as well as the degree of discomfort were explored. RESULTS: The overall experience with the device was significantly better for the CDA group than for the FFRD group. Both groups felt that delivery and removal of the appliance was quick and easy, the appliance was noticeable to some extent, and the majority became accustomed to it within two weeks with a maximum of one month. In general, associated discomfort and effects on daily life and activities were less for the CDA group than for the FFRD group. Side effects decreased over time for both groups, often more so for the CDA group. The major side effects experienced by the CDA group were difficulty eating and sore teeth, and these improved significantly over time. Soreness from the appliance rubbing on the cheek or lip was significantly less for the CDA group. CONCLUSION: The CDA appears to be more comfortable, offers a more positive overall experience, and has fewer negative comfort-related side effects compared to FFRD.