Cataract Formation and Low-Dose Radiation Exposure from Head Computed Tomography (CT) Scans in Ontario, Canada, 1994-2015.

Ionizing radiation exposure to the lens of the eye is a known cause of cataractogenesis. Administrative data from the Ontario Health Insurance Program was used to examine the association between low-dose radiation exposure from head CT scans and cataract extraction surgery for 16 million Ontarians over a 22-year period (1994-2015). Subjects were grouped based on the number of head CT scans they received, and a Cox proportional hazards analysis was used to determine if there was a correlation with cataract surgery. Covariates included in the analysis were age, sex, diabetes, hypertension and prior history of intraocular surgery. To account for the potentially long latency period between radiation exposure and cataract formation, the data were analyzed incorporating a 5- and 10-year lag between head CT scan exposure and cataract surgery. Both the 5- and 10-year lagged models followed a similar trend, where only the first three head CT scans significantly increased the risk of cataract surgery by 3-8%. Individuals receiving four or more head CT scans did not have an increased cataract risk and in several cases the risk was reduced. Overall, no positive dose-response relationship was seen between the number of head CT scans received and the risk of cataract surgery. Due to the nature of the data extracted from medical records, several uncertainties exist in the analysis related to dosimetry, ultraviolet light exposure and smoking status. Nonetheless, these results do not support an association between ionizing radiation from repeated head CT scans and cataract formation.

Physical and mental health inequalities among aging lesbian, gay, and bisexual Canadians: cross-sectional results from the Canadian Longitudinal Study on Aging (CLSA).

OBJECTIVE: International estimates suggest the presence of health inequalities among older sexual minorities (i.e., individuals who identify as lesbian, gay, or bisexual and are 65 years old or above). In this study, we investigated the presence of health inequalities among aging lesbian and bisexual females, as well as aging gay and bisexual males in Canada. METHODS: We used baseline data from the Canadian Longitudinal Study on Aging (CLSA) Tracking and Comprehensive cohorts to cross-sectionally compare self-reported physical and mental health indicators by sex and sexual orientation. Within our analysis sample of 51,208 Canadians 45 years old and over, 2% (n = 1057) of respondents identified as lesbian, gay, or bisexual. RESULTS: Compared to heterosexual female peers, lesbian and bisexual females had greater odds of heavy drinking (AOR = 1.8, 95% CI = 1.3-2.4) and being a former smoker (AOR = 1.5, 95% CI = 1.2-1.9). Gay and bisexual males had greater odds of reporting a diagnosis of cancer (AOR = 1.5, 95% CI = 1.0-1.9) and currently smoking (AOR = 1.5, 95% CI = 1.1-2.0), compared to heterosexual males. Female and male sexual minorities had greater odds of reporting mood disorders (including depression) and anxiety disorders relative to heterosexual peers of the same sex. CONCLUSION: These findings highlight the importance of considering both sex and sexual orientation when developing approaches to support the physical and mental health of a diverse aging population in Canada.

Community-randomised controlled trial embedded in the Anishinaabek Cervical Cancer Screening Study: human papillomavirus self-sampling versus Papanicolaou cytology.

OBJECTIVES: The incidence of cervical cancer is up to 20-fold higher among First Nations women in Canada than the general population, probably due to lower participation in screening. Offering human papillomavirus (HPV) self-sampling in place of Papanicolaou (Pap) testing may eventually increase screening participation and reduce cervical cancer rates in this population. DESIGN: A community-randomised controlled screening trial. SETTING: First Nations communities in Northwest Ontario, Canada. PARTICIPANTS: Women aged between 25 and 69, living in Robinson Superior Treaty First Nations. The community was the unit of randomisation. INTERVENTIONS: Women were asked to complete a questionnaire and have screening by HPV self-sampling (arm A) or Pap testing (arm B). PRIMARY OUTCOME MEASURES: The number of women who participated in cervical screening. RANDOMISATION: Community clusters were randomised to include approximately equivalent numbers of women in each arm. RESULTS: 6 communities were randomised to arm A and 5 to arm B. One community withdrew, leaving 5 communities in each group (834 eligible women). Participation was <25%. Using clustered intention-to-treat (ITT) analysis, initial and cumulative averaged uptakes in arm A were 1.4-fold (20% vs 14.3%, p=0.628) and 1.3-fold (20.6% vs 16%, p=0.694) higher compared to arm B, respectively. Corresponding per protocol (PP) analysis indicates 2.2-fold (22.9% vs 10.6%, p=0.305) and 1.6-fold (22.9% vs 14.1%, p=0.448) higher uptakes in arm A compared to arm B. Screening uptake varied between communities (range 0-62.1%). Among women who completed a questionnaire (18.3% in arm A, 21.7% in arm B), the screening uptake was 1.8-fold (ITT; p=0.1132) or 3-fold (PP; p<0.01) higher in arm A versus arm B. CONCLUSIONS: Pap and HPV self-sampling were compared in a marginalised, Canadian population. Results indicated a preference for self-sampling. More research on how to reach underscreened Indigenous women is necessary. TRIAL REGISTRATION NUMBER: ISRCTN84617261.

How to report and interpret screening test properties: guidelines for driving researchers.

One important goal of driving research is the development of a short but valid office-based screening test for fitness to drive of aging drivers. Several candidate tests have been proposed already, and no doubt others will be proposed in the future. It might seem obvious that authors advocating for the adoption of a particular screening test or procedure should report sensitivity, specificity, and other common screening test properties. Unfortunately, driving researchers have frequently failed to report any screening test properties. Others have reported screening test properties but have made basic mistakes such as calculating predictive values of positive and negative tests but reporting them incorrectly as sensitivity and specificity. These omissions and errors suggest that some driving researchers may be unaware of the importance of accurately reporting test properties when proposing a screening procedure and that others may need a refresher on how to calculate and interpret the most common screening test properties. Many good learning resources for screening and diagnostic tests are available, but most of them are intended for students and researchers in medicine, epidemiology, or public health. We hope that this tutorial in a prominent transportation journal will help lead to improved reporting and interpretation of screening test properties in articles that assess the usefulness of potential screening tools for fitness to drive.

It is premature to test older drivers with the SIMARD-MD.

BACKGROUND: A new tool, the SIMARD-MD, has been proposed to help physicians identify cognitively impaired drivers who may be unfit to drive, but little empirical evidence is available to justify its use. We analyzed data from a cohort of older Canadian drivers who had undergone cognitive testing to: (1) correlate the SIMARD-MD with other tools that measure cognition (e.g., trail-making test), (2) identify how many drivers, using published cut-offs on the SIMARD-MD, would be recommended to lose their license, or be considered fit to drive, or be required to undergo further driving assessment, and (3) determine if the SIMARD-MD is biased by level of education as many cognitive tools are. METHODS: Cross-sectional data from 841 drivers aged 70 and over from seven Canadian sites who are enrolled in a 5-year cohort study were used for the analyses. Scores on the SIMARD-MD were correlated with scores on the other cognitive measures. The recommendations that would be made based on the SIMARD-MD scores were based on published cut-off values suggested by the authors of the tool. The impact of education status was examined using linear regression controlling for age. RESULTS: Correlations between the SIMARD-MD and other cognitive measures ranged from .15 to .86. Using published cut-off scores, 21 participants (2.5%) would have been recommended to relinquish their licenses, 428 (50.9%) would have been deemed fit to drive, and 392 (46.6%) would have been required to undergo further testing. We found a difference of 8.19 points (95% CI=4.99, 11.40, p<.001) in favor of drivers with post-secondary education versus those without, representing over 11% of the mean score. DISCUSSION: The SIMARD-MD is unlikely to be valuable to clinicians because it lacks sufficient precision to provide clear recommendations about fitness-to-drive. Recommendations based solely on the SIMARD-MD may place many seniors at risk of losing their transportation mobility or incurring unnecessary stress and costs to prove they are safe to drive. Furthermore, the education bias may create an unwanted structural inequity. Hence, adoption of the SIMARD-MD as a tool to determine fitness-to-drive appears premature.

Feasibility of self-sampling and human papillomavirus testing for cervical cancer screening in First Nation women from Northwest Ontario, Canada: a pilot study.

Background The incidence of cervical cancer is up to sixfold higher among First Nation women in Canada than in the general population. This is probably due to lower participation rates in cervical cancer prevention programmes. Objective To raise screening participation in this underserved population by launching an alternative approach to (Pap)anicolaou testing in a clinic-namely, vaginal self-sampling followed by human papillomavirus (HPV) diagnostics. Methods Good relationships were established with a First Nation community of the Northern Superior region in Northwest Ontario, and then 49 community women, aged 25-59, were recruited, who provided a vaginal self-sample and answered a questionnaire. Frequency distributions and cross-tabulations were used to summarise the data. Associations between categorical variables were assessed using the χ(2) test of association, or the Goodman-Kruskal γ if both variables had ordered categories. Self-collected samples were tested for integrity and HPV using optimised molecular biological methods. Results The majority of participants (87.2%) were amenable to future HPV screening by self-sampling. This finding was independent of age, educational level and a previous history of abnormal Pap tests. Interestingly, the preferred way to learn about sexual health remained through interaction with healthcare professionals. As defined by the presence of a housekeeping gene, self-sample integrity was high (96%). Using polymerase chain reaction-based Luminex typing, the overall HPV positivity was 28.6% (ie, with either a low- or high-risk type) and 16.3% were infected with a high-risk type such as HPV16. Conclusion In this pilot study of First Nation women, self-sampling and HPV testing was well received and self-sample quality was excellent. A larger survey to be conducted in other Northern Superior communities in Northwest Ontario will determine whether this approach could become a viable screening strategy for First Nation women.

Agreement among Canadian retina specialists in the determination of treatment eligibility for photodynamic therapy in age-related macular degeneration.

OBJECTIVES: To determine inter- and intraobserver agreement among Canadian retina specialists in their angiographic classification of choroidal neovascularization and their decision to treat with photodynamic therapy. Agreement was also determined between retina specialists and a Reading Center. METHODS: Forty retina specialists graded 24 cases of exudative age-related macular degeneration on two occasions separated by 6 months. Participants were asked to categorize the choroidal neovascularization and indicate if they would treat with photodynamic therapy. Agreement was determined for decision to treat and for interpretation of the fluorescein angiogram. Angiographic interpretation by participants was compared with that of the Reading Center. RESULTS: The kappas among the 40 participants for lesion categorization and treatment decision were 0.43 (95% confidence interval: 0.36-0.52) and 0.29 (95% confidence interval: 0.18-0.42), respectively. The kappa for intraobserver agreement was 0.57 (95% confidence interval: 0.50-0.64) for lesion categorization and 0.58 (95% confidence interval: 0.43-0.74) for treatment decision. The mean percent agreement with the Reading Center for lesion categorization was 65.4%. CONCLUSIONS: There was moderate interobserver agreement for choroidal neovascularization categorization and poor agreement among Canadian retina specialists for decision to treat with photodynamic therapy. There was moderate intraobserver agreement for both treatment decision and lesion categorization. There was moderate agreement between observers and the Reading Center for angiographic choroidal neovascularization categorization.

Maternal outcomes of cesarean sections: do generalists' patients have different outcomes than specialists' patients?

OBJECTIVE: To compare maternal outcomes of cesarean sections performed by GPs with the outcomes of those performed by specialists. DESIGN: Retrospective, comorbidity-adjusted study. SETTING: Mostly small isolated rural hospitals in Ontario, British Columbia, Alberta, and Saskatchewan compared with all levels of specialist obstetric programs offered in Canada. PARTICIPANTS: Fifteen GPs with less than 1 year of surgical training who performed cesarean sections. METHOD: Using data from the Canadian Institute for Health Information's Discharge Abstracts Database for the years 1990 to 2001, we matched each of 1448 cesarean section cases managed by these GPs to 3 cases managed by specialists and looked for comorbidity. In total, we analyzed the outcomes of 5792 cesarean sections. MAIN OUTCOME MEASURES: Composites of major morbidity possibly attributable to surgery:death, sepsis, cardiac arrest, shock, hypotension, ileus or bowel obstruction,major puerperal infection, septic or fat embolism, postpartum hemorrhage requiring hysterectomy, need for cardiopulmonary resuscitation, or another operation; and all major morbidity: major surgical morbidity, acute coronary syndrome, endocarditis, pulmonary edema, cerebrovascular disorder, pneumothorax, respiratory failure, amniotic fluid embolism, complications of anesthesia, deep vein thrombosis, pulmonary embolism, acute renal failure, and need for mechanical ventilation. RESULTS: The rate of all major morbidity was higher among GPs' patients than among specialists' patients (3.1% vs 1.9%, odds ratio [OR] 1.6, 95% confidence interval [CI] 1.1 to 2.3, P = .009) as was the rate of major surgical morbidity (2.5% vs 1.6%, OR 1.6, 95% CI 1.1 to 2.4, P = .024). Differences in major morbidity variables were not significant if major postpartum infection was excluded (all major morbidity 1.5% vs 1.1%, major surgical morbidity 1.0% vs 0.8%). Secondary outcomes included rate of transfer to acute care institutions (6.0% vs 1.5%, OR 4.6, 95% CI 3.6 to 6.5, P < .001), mean length of hospital stay (5.2 vs 4.9 days, P= .006), need for blood transfusion (5.9% vs 7.0%, OR 0.76, 95% CI 0.5 to 1.1, P = .11) and frequency of surgical error (0.8% vs 0.7%, OR 1.1, 95% CI 0.6 to 2.3, P = .72). CONCLUSION: Although major morbidity was higher among GPs' patients, differences were entirely attributable to the rate of postpartum infection. Infection rates in both groups were far below expected rates. The observation that blood transfusion and surgical error rates were similar suggests that surgical technique was not the cause of differences between groups. We conclude that these GPs with a mean of 4 months' training subsequently performed cesarean sections with an acceptable degree of safety compared with specialists.

Health-related quality of life in women with polycystic ovary syndrome, a self-administered questionnaire, was validated.

OBJECTIVE: We examined the measurement properties of a questionnaire (PCOSQ) measuring health-related quality of life (HRQOL) in women with the polycystic ovary syndrome (PCOS). STUDY DESIGN: This multicenter prospective randomized placebo-controlled blinded study enrolled 393 patients with PCOS at tertiary care sites. Participants were randomized to placebo or troglitazone (150 mg/d, 300 mg/d, or 600 mg/d). At baseline (n=393) and after 44 weeks of treatment (n=284) the proportion of normal menstrual cycles, the free testosterone (T) level, four objective measures of facial hair growth (hair density and hair growth rate by photography, and hair diameter and hair growth rate using plucked hairs), and a subjective assessment of the degree of hirsutism, the modified Ferriman-Gallwey (F-G) score, were determined. At both visits, patients also completed the PCOSQ. Since the trial was conducted, troglitazone has been removed from the market because of toxic effects. The PCOSQ includes 26 questions (items) that address five areas of concern (domains), including emotions, body hair, body weight, fertility, and menstruation rated on a seven-point scales in which lower scores denote higher degrees of patient concern and a lower HRQOL. RESULTS: Cronbach's alpha was >0.7 for four of five domains. Factor analysis provided moderate to strong support for the five-domain structure of the PCOSQ. Cross-sectional correlations were weak with all measures but the F-G score and hair growth (r=-.46, P < .01). The change in the F-G score showed a statistically significant (P < .01) correlation with changes in PCOSQ hair growth (r=-.22), weight (r=-.17), infertility (r=-.20), and menstruation (r=-.20). Changes in the proportion of normal menstrual cycles correlated with change in the infertility domain (r=.14, P < .03) and with the change in the menstruation domain (r=.31, P < .001). The PCOSQ proved as responsive as the F-G, and more responsive than the objective measures of hair growth, to effects of troglitazone. CONCLUSIONS: Our data provides some support for the discriminative and longitudinal validity, and appreciable support for the responsiveness, of the PCOSQ.

Meta-analyses of therapies for postmenopausal osteoporosis. IV. Meta-analysis of raloxifene for the prevention and treatment of postmenopausal osteoporosis.

OBJECTIVE: To review the effect of raloxifene on bone density and fractures in postmenopausal women. DATA SOURCE: We searched MEDLINE from 1966 to 2000 and examined citations of relevant articles and the proceedings of international osteoporosis meetings. STUDY SELECTION: We included seven trials that randomized women to raloxifene or placebo, with both groups receiving similar calcium and vitamin D supplementation, and measured bone density for at least one year. DATA EXTRACTION: For each trial, three independent reviewers abstracted the data and assessed the methodological quality using a validated tool. DATA SYNTHESIS: Data from one large dominating trial suggest a reduction in vertebral fractures with a relative risk (RR) of 0.60 [95% confidence interval (CI) 0.50-0.70, P < 0.01]. The RR of nonvertebral fractures in patients given 60 mg or more of raloxifene in the larger study was 0.92 (95% CI 0.79-1.07, P = 0.27). Raloxifene resulted in positive effects on the percentage change in bone density, which increased over time and was independent of dose. At the final year, point estimates and 95% CIs for the differences in percent change in bone density (95% CI) between raloxifene and placebo groups were 1.33 (95% CI 0.37-2.30) for total body, 2.51 (95% CI 2.21-2.82) for lumbar spine, 2.05 (95% CI 0.71-3.39) for combined forearm, and 2.11 (95% CI 1.68-2.53) for combined hip (P < 0.01 at all four sites). Results were similar across studies, and formal tests of heterogeneity did not approach conventional statistical significance. Raloxifene slightly increased rates of withdrawal from therapy as a result of adverse effects (RR 1.15, 95% CI 1.00-1.33, P = 0.05). The pooled RR was significant for hot flashes 1.46 (95% CI 1.23-1.74, P < 0.01) and nonsignificant for leg cramps 1.64 (95% CI 0.84-3.20, P = 0.15). CONCLUSION: Raloxifene increases bone density, and the effect increases over 2 yr. The data suggest a positive impact of raloxifene on vertebral fractures. There was little effect of raloxifene on nonvertebral fractures.