Comparative Effectiveness of Total Hip Arthroplasty and Hemiarthroplasty for Femoral Neck Fracture: A Propensity-Score-Matched Cohort Study.

BACKGROUND: The optimal treatment of older patients with a displaced femoral neck fracture remains a controversial topic. This study aimed to compare clinical outcomes across a matched group of patients with a femoral neck fracture treated with either hemiarthroplasty or total hip arthroplasty (THA). METHODS: Routinely collected health-care databases were linked to create a population-based cohort of 49,597 patients ≥60 years old from Ontario, Canada, who underwent hemiarthroplasty or THA for a femoral neck fracture between 2002 and 2017. A propensity-score-matched cohort was created using relevant and available predictors of treatment assignment and outcomes of interest. Clinical outcomes consisting of hip dislocation, revision surgery, hospital readmission, and death were compared in the matched cohort using survival analysis. RESULTS: Over 99% of THA patients (4,612) were adequately matched 1:1 to hemiarthroplasty patients (total matched cohort = 9,224). Patients treated with THA were at higher risk for hip dislocation at 30 days and 1 and 2 years postoperatively (2-year risk, 1.8% for THA versus 0.8% for hemiarthroplasty; p < 0.001). There was no difference in the short-term (30-day) or long-term (up to 10-year) risk of revision surgery between treatment groups. There was no significant difference in the risk of 30-day hospital readmission between groups. The risk of death at 1 year and 2 years postoperatively was lower for patients treated with THA. CONCLUSIONS: For patients with a hip fracture, shared decision-making should involve discussion of the potential higher risk of short-term hip dislocation after THA compared with hemiarthroplasty. The risk of revision surgery was similar between treatment groups at up to 10 years of follow-up. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Association of topical glaucoma medications with lacrimal drainage obstruction and eyelid malposition.

BACKGROUND/OBJECTIVES: Adverse effects of topical glaucoma medications (TGMs) may include development of ocular adnexal disorders. We undertook a study to determine the effect of TGMs on the risk of developing lacrimal drainage obstruction (LDO) and eyelid malposition. SUBJECTS/METHODS: All patients 66 years of age and older in Ontario, Canada initiating TGM and all patients diagnosed with glaucoma/suspected glaucoma but not receiving TGM from 2002 to 2018 were eligible for inclusion in this retrospective cohort study. Using validated healthcare administrative databases, cohorts were identified with TGM and no TGM patients matched 1:2 on sex and birth year. The effect of TGM treatment on risk of surgery for LDO and lid malpositions was estimated using Kaplan-Meier and Cox proportional hazards models. RESULTS: Cohorts included 122,582 patients in the TGM cohort and 232,336 patients in the no TGM cohort. Among the TGM cohort there was decreased event-free survival for entropion (log-rank P < 0.001), trichiasis (P < 0.001), and LDO (P = 0.006), and increased ectropion-free survival (P = 0.007). No difference in ptosis-free survival was detected (P = 0.78). For the TGM cohort there were increased hazards for entropion (hazard ratio [HR] 1.24, 95% confidence interval [CI] 1.12-1.37; P < 0.001), trichiasis (HR 1.74, 95% CI 1.57-1.94; P < 0.001), and LDO (at 15 years: HR 2.39, 95% CI 1.49-3.85; P = 0.004), and a decreased hazard for ectropion (HR 0.89, 95% CI 0.81-0.97; P = 0.008). No association between TGM treatment and ptosis hazard was detected (HR 0.99, 95% CI 0.89-1.09; P = 0.78). CONCLUSIONS: TGMs are associated with an increased risk of undergoing surgery for LDO, entropion, and trichiasis.

The impact of image resolution on power, bias, and confounding: A simulation study of ambient light at night exposure.

Studies of the impact of environmental pollutants on health outcomes can be compromised by mismeasured exposures or unmeasured confounding with other environmental exposures. Both problems can be exacerbated by measuring exposure from data sources with low spatial resolution. Artificial light at night, for example, is often estimated from low-resolution satellite images, which may result in substantial measurement error and increased correlation with air or noise pollution. METHODS: Light at night exposure was considered in simulated epidemiologic studies in Vancouver, British Columbia. First, we assessed statistical power and bias for hypothetical studies that replaced true light exposure with estimates from sources with low resolution. Next, health status was simulated based on pollutants other than light exposure, and we assessed the frequency with which studies might incorrectly attribute negative health impacts to light exposure as a result of unmeasured confounding by the other environmental exposures. RESULTS: When light was simulated to be the causal agent, studies relying on low-resolution data suffered from lower statistical power and biased estimates. Additionally, correlations between light and other pollutants increased as the spatial resolution of the light exposure map decreased, so studies estimating light exposure from images with lower spatial resolution were more prone to confounding. CONCLUSIONS: Studies estimating exposure to pollutants from data with lower spatial resolution are prone to increased bias, increased confounding, and reduced power. Studies examining effects of light at night should avoid using exposure estimates based on low-resolution maps, and should consider potential confounding with other environmental pollutants.

The Associations of Shift Work, Sleep Quality, and Incidence of Hypertension in Ontario Adults: A Population-Based Study.

BACKGROUND: Relatively few population-based studies have explored the relationship and potential mechanisms between exposure to shift work and hypertension. The study objectives for this study were to determine 1) if history of shift work was associated with increased rates of hypertension among working adults, and 2) if sleep quality mediated this relationship. METHODS: We conducted a population-based cohort study using data from Ontario respondents (aged 35-69 y) in the 2000-2001 Canadian Community Health Survey, which was linked to administrative health data housed at the Institute for Clinical Evaluative Sciences. Our sample included survey participants who were employed with no previous diagnosis of hypertension (n = 7420). During a 12-year follow-up window, we determined the time of hypertension diagnosis based on a previously validated algorithm; and explored the mediating effect of sleep quality using marginal structural effect models. RESULTS: The study sample included 2079 shift workers and 5341 day workers. Shift workers reported less refreshing sleep, more trouble sleeping, and poorer sleep quality overall compared with day workers. In 12 years of follow-up, 31.3% of workers developed hypertension. History of shift work was associated with higher hypertension rates in both men (hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.02-1.44) and women (HR 1.26, 95% CI 1.03-1.55). There was no evidence that these associations were mediated by past sleep quality. CONCLUSIONS: History of shift work schedules is associated with increased rates of hypertension. Shift work disrupts sleep, but further longitudinal studies are needed to determine if sleep quality mediates the association between shift work and hypertension.

Outdoor light at night at residences and breast cancer risk in Canada.

Experimental and epidemiologic studies suggest that light at night (LAN) exposure disrupts circadian rhythm, and this disruption may increase breast cancer risk. We investigated the potential association between residential outdoor LAN and breast cancer risk. A population-based case-control study was conducted in Vancouver, British Columbia and Kingston, Ontario, Canada with incident breast cancer cases, and controls frequency matched by age in the same region. This analysis was restricted to 844 cases and 905 controls who provided lifetime residential histories. Using time-weighted average duration at each home 5-20 years prior to study entry, two measures of cumulative average outdoor LAN were calculated using two satellite data sources. Logistic regression was used to estimate the relationship between outdoor LAN and breast cancer risk, considering interactions for menopausal status and night shift work. We found no association between residential outdoor LAN and breast cancer for either measure of LAN [OR comparing highest vs. lowest tertile (DNB) = 0.95, 95% CI 0.70-1.27]. We also found no association when considering interactions for menopausal status and past/current night work status. These findings were robust to changes to years of residential data considered, residential mobility, and longer exposure windows. Our findings are consistent with studies reporting that outdoor LAN has a small effect or no effect on breast cancer risk.

An Investigation of Chiropractor-Directed Weight-Loss Interventions: Secondary Analysis of O-COAST.

OBJECTIVE: The purpose of this study was to investigate weight-loss interventions offered by Canadian doctors of chiropractic to their adult patients. METHODS: This paper reports a secondary analysis of data from the Ontario Chiropractic Observation and Analysis STudy (Nc = 42 chiropractors, Np = 2162 patient encounters). Multilevel logistic regression was performed to assess the odds of chiropractors initiating or continuing weight management interventions with patients. Two chiropractor variables and 8 patient-level variables were investigated for influence on chiropractor-directed weight management. In addition, the interaction between the effects of patient weight and comorbidity on weight management interventions by chiropractors was assessed. RESULTS: Around two-thirds (61.3%) of patients who sought chiropractic care were either overweight or had obesity. Very few patients had weight loss managed by their chiropractor. Among patients with body mass index equal to or greater than 18.5 kg/m2, guideline recommended weight management was initiated or continued by Ontario chiropractors in only 5.4% of encounters. Chiropractors did not offer weight management interventions at different rates among patients who were of normal weight, overweight, or obese (P value = 0.23). Chiropractors who graduated after 2005 who may have been exposed to reforms in chiropractic education to include public health were significantly more likely to offer weight management than chiropractors who graduated between 1995 and 2005 (odds ratio 0.02; 95% CI [0.00-0.13]) or before 1995 (odds ratio 0.08; 95% CI [0.01-0.42]). CONCLUSION: The prevalence of weight management interventions offered to patients by Canadian chiropractors in Ontario was low. Health care policy and continued chiropractic educational reforms may provide further direction to improve weight-loss interventions offered by doctors of chiropractic to their patients.

Impact of exposure to phenols during early pregnancy on birth weight in two Canadian cohort studies subject to measurement errors.

BACKGROUND: It is of interest to know whether early pregnancy exposure to phenols such as bisphenol-A (BPA) or triclosan (TCS) negatively impacts birth weight outcomes. Exposure to these chemicals is widespread in the Canadian population but obtaining accurate measurements of average exposure is difficult because these chemicals are rapidly excreted from the body, causing body levels to fluctuate both within and between days, as observed in a recent Canadian study (P4). This measurement error can attenuate the estimated effects of exposures. METHODS: Data from two Canadian cohort studies, the Plastics and Personal-care Products use in Pregnancy (P4) Study and the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, such that all participants with complete BPA or TCS exposure and outcome data were used (MIREC n = 1822, P4 n = 68). We used regression calibration to correct for the attenuating effects of exposure measurement error when modeling the effect of first trimester BPA or TCS exposure on four birth weight outcomes: birth weight (BW), low birth weight (LBW), small for gestational age (SGA) and large for gestational age (LGA). Specific gravity, time of day, and time since last urine void were also controlled in the analysis. RESULTS: TCS exposure has a marginally significant association with SGA only with odds ratio 0.87 and 95% confidence interval (0.74, 1.00). It also has a marginally significant association with LGA in male offspring with odds ratio 1.11 and 95% confidence interval (1.00, 1.25). The effects of BPA on the four birth outcomes were insignificant. CONCLUSIONS: Increased TCS exposure during pregnancy is marginally associated with decreased odds of having SGA offspring. It is possibly associated with decreased BW in males and decreased odds of LBW, though these associations were not present in measurement error corrected models. TCS is possibly associated with increased odds in male offspring of being LGA, though this relationship was not present in models not corrected for measurement error. The study finds no significant effects of BPA on birth weight outcomes, which may be due to more severe measurement error in a single observation of BPA.

The impact of drug coverage on viral suppression among people living with HIV in Ontario, Canada.

OBJECTIVES: We investigated the effect of drug coverage on viral suppression (sVL) in Ontario, Canada, where there is no universal coverage of prescription drugs, including antiretroviral therapy (ART). METHODS: Ontarians without employment coverage may be eligible for varying degrees of coverage through government-sponsored programs. Remaining individuals pay all expenses entirely out of pocket. Among participants on ART enrolled in the Ontario HIV Treatment Network Cohort Study (OCS) who were interviewed in 2008-2013 with known or imputable drug coverage, we estimated the prevalence with sVL (< 200 copies/mL) as of their last viral load each year. We calculated prevalence ratios (PR) according to time-updated socio-economic and behavioural factors using multivariable generalized estimating equations with a log-link function. Multiple imputation was used to assess the sensitivity of these findings to different assumed missing data models. RESULTS: One thousand two hundred forty-seven participants were included (3463 person-years). Compared to study participants with employer coverage, individuals covered through the Ontario Drug Benefit (ODB) were less likely to be suppressed (PR, 95% confidence interval (CI) 0.96, 0.93-0.98). After multivariable adjustment, ODB remained independently associated with less success in achieving sVL (adjusted PR, 95% CI 0.98, 0.95-0.99). These findings were robust to different assumptions about the missing data. CONCLUSION: Our findings suggest that drug coverage can affect viral suppression in our setting. Further research is needed to identify the mechanisms by which coverage interacts with individual patient factors to affect viral suppression. Mechanisms to improve access and coverage for ART are needed.

Adaptive sampling in two-phase designs: a biomarker study for progression in arthritis.

Response-dependent two-phase designs are used increasingly often in epidemiological studies to ensure sampling strategies offer good statistical efficiency while working within resource constraints. Optimal response-dependent two-phase designs are difficult to implement, however, as they require specification of unknown parameters. We propose adaptive two-phase designs that exploit information from an internal pilot study to approximate the optimal sampling scheme for an analysis based on mean score estimating equations. The frequency properties of estimators arising from this design are assessed through simulation, and they are shown to be similar to those from optimal designs. The design procedure is then illustrated through application to a motivating biomarker study in an ongoing rheumatology research program.

Incomplete data in randomized dermatology trials: consequences and statistical methodology.

Randomized clinical trials can provide the highest level of evidence regarding the effectiveness of therapeutic interventions. When individuals in trials do not complete the planned treatment period it is often not possible to observe the desired outcomes, which results in incomplete data. Here we review various mechanisms which can lead to incomplete data, discuss the impact of these mechanisms, and present strategies for dealing with incomplete data. We discuss these issues in the context of clinical trials in dermatology and provide practical recommendations for planning and drawing conclusions from studies which could involve incomplete data.