Polycystic Ovary Syndrome, Gestational Diabetes Mellitus, and the Mediating Role of Obesity: A Population-Based Cohort Study

This population-based cohort study in Ontario, Canada evaluated the association between polycystic ovary syndrome (PCOS) and gestational diabetes mellitus, and the mediating effect of obesity. The study included 1 268 901 pregnancies between 2006 and 2018; 387 748 with maternal PCOS and 881 153 without PCOS. Modified Poisson regression generated relative risks adjusted for maternal covariates. Causal mediation analyses accounted for the indirect effect of obesity. Relative to individuals without PCOS, those with PCOS had a slightly higher rate (6.0% vs. 4.9%) and adjusted relative risk (1.05; 95% CI 1.03-1.06) of gestational diabetes mellitus. Obesity mediated a significant proportion (90%) of this association. Preconception counselling and future research should include strategies to support weight optimization in patients with PCOS.

Endometriosis and mental health: a population-based cohort study

BACKGROUND

Endometriosis is a chronic gynecologic disorder that leads to considerable pain and a reduced quality of life. Although its physiological manifestations have been explored, its impact on mental health is less well defined. Existing studies of endometriosis and mental health were conducted within diverse healthcare landscapes with varying access to care and with a primary focus on surgically diagnosed endometriosis. A single-payer healthcare system offers a unique environment to investigate this association with fewer barriers to access care while considering the mode of endometriosis diagnosis.

OBJECTIVE

Our objective was to assess the association between endometriosis and the risk for mental health conditions and to evaluate differences between patients diagnosed medically and those diagnosed surgically.

STUDY DESIGN

A matched, population-based retrospective cohort study was conducted in Ontario and included patients aged 18 to 50 years with a first-time endometriosis diagnosis between January 1, 2010, and July 1, 2020. Endometriosis exposure was determined through either medical or surgical diagnostic criteria. A medical diagnosis was defined by the use of the corresponding International Classification of Disease diagnostic codes from outpatient and in-hospital visits, whereas a surgical diagnosis was identified through inpatient or same-day surgeries. Individuals with endometriosis were matched 1:2 on age, sex, and geography to unexposed individuals without a history of endometriosis. The primary outcome was the first occurrence of any mental health condition after an endometriosis diagnosis. Individuals with a mental health diagnosis in the 2 years before study entry were excluded. Cox regression models were used to generate hazard ratios with adjustment for hysterectomy, salpingo-oophorectomy, infertility, pregnancy history, qualifying surgery for study inclusion, immigration status, history of asthma, abnormal uterine bleeding, diabetes, fibroids, hypertension, irritable bowel disorder, migraines, and nulliparity.

RESULTS

A total of 107,832 individuals were included, 35,944 with a diagnosis of endometriosis (29.5% medically diagnosed, 60.5% surgically diagnosed, and 10.0% medically diagnosed with surgical confirmation) and 71,888 unexposed individuals. Over the study period, the incidence rate was 105.3 mental health events per 1000 person-years in the endometriosis group and 66.5 mental health events per 1000 person-year among unexposed individuals. Relative to the unexposed individuals, the adjusted hazard ratio for a mental health diagnosis was 1.28 (95% confidence interval, 1.24-1.33) among patients with medically diagnosed endometriosis, 1.33 (95% confidence interval, 1.16-1.52) among surgically diagnosed patients, and 1.36 (95% confidence interval, 1.2-1.6) among those diagnosed medically with subsequent surgical confirmation. The risk for receiving a mental health diagnosis was highest in the first year after an endometriosis diagnosis and declined in subsequent years. The cumulative incidence of a severe mental health condition requiring hospital visits was 7.0% among patients with endometriosis and 4.6% among unexposed individuals (hazard ratio, 1.56; 95% confidence interval, 1.53-1.59).

CONCLUSION

Endometriosis, regardless of mode of diagnosis, is associated with a marginally increased risk for mental health conditions. The elevated risk, particularly evident in the years immediately following the diagnosis, underscores the need for proactive mental health screening among those newly diagnosed with endometriosis. Future research should investigate the potential benefits of mental health interventions for people with endometriosis with the aim of enhancing their overall quality of life.

Infertility and Risk of Autism Spectrum Disorder in Children

Importance

Previous studies on the risk of childhood autism spectrum disorder (ASD) following fertility treatment did not account for the infertility itself or the mediating effect of obstetrical and neonatal factors.

Objective

To assess the association between infertility and its treatments on the risk of ASD and the mediating effect of selected adverse pregnancy outcomes on that association.

Design, Setting, and Participants

This was a population-based cohort study in Ontario, Canada. Participants were all singleton and multifetal live births at 24 or more weeks' gestation from 2006 to 2018. Data were analyzed from October 2022 to October 2023.

Exposures

The exposure was mode of conception, namely, (1) unassisted conception, (2) infertility without fertility treatment (ie, subfertility), (3) ovulation induction (OI) or intrauterine insemination (IUI), or (4) in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI).

Main Outcome and Measures

The study outcome was a diagnosis of ASD at age 18 months or older. Cox regression models generated hazard ratios (HR) adjusted for maternal and infant characteristics. Mediation analysis further accounted for the separate effect of (1) preeclampsia, (2) cesarean birth, (3) multifetal pregnancy, (4) preterm birth at less than 37 weeks, and (5) severe neonatal morbidity.

Results

A total of 1 370 152 children (703 407 male [51.3%]) were included: 1 185 024 (86.5%) with unassisted conception, 141 180 (10.3%) with parental subfertility, 20 429 (1.5%) following OI or IUI, and 23 519 (1.7%) following IVF or ICSI. Individuals with subfertility or fertility treatment were older and resided in higher-income areas; the mean (SD) age of each group was as follows: 30.1 (5.2) years in the unassisted conception group, 33.3 (4.7) years in the subfertility group, 33.1 (4.4) years in the OI or IUI group, and 35.8 (4.9) years in the IVF or ICSI group. The incidence rate of ASD was 1.93 per 1000 person-years among children in the unassisted conception group. Relative to the latter, the adjusted HR for ASD was 1.20 (95% CI, 1.15-1.25) in the subfertility group, 1.21 (95% CI, 1.09-1.34) following OI or IUI, and 1.16 (95% CI, 1.04-1.28) after IVF or ICSI. Obstetrical and neonatal factors appeared to mediate a sizeable proportion of the aforementioned association between mode of conception and ASD risk. For example, following IVF or ICSI, the proportion mediated by cesarean birth was 29%, multifetal pregnancy was 78%, preterm birth was 50%, and severe neonatal morbidity was 25%.

Conclusions and Relevance

In this cohort study, a slightly higher risk of ASD was observed in children born to individuals with infertility, which appears partly mediated by certain obstetrical and neonatal factors. To optimize child neurodevelopment, strategies should further explore these other factors in individuals with infertility, even among those not receiving fertility treatment.

Renal colic imaging practice patterns in Ontario: A population-based study

INTRODUCTION

Computed tomography (CT) scans are associated with increased cost and exposure to radiation when compared to ultrasound (US) in patients presenting with renal colic. Consequently, a Choosing Wisely recommendation from 2014 states that US should be used over CT in uncomplicated presentations of renal colic in patients under the age of 50. The objective of this study was to describe imaging practice patterns in Ontario among patients presenting with renal colic and the relationship between initial imaging modality, subsequent imaging, and burden of care indicators.

METHODS

This is a population-based study of patients who presented with renal colic in Ontario between 2003 and 2019 using administrative data. Patients were assessed according to the first imaging modality they had during their index visit. Descriptive statistics and the Chi-squared test were used to examine differences between these groups. The primary outcome was the need for subsequent imaging. Secondary outcomes included length of renal colic episode, days to surgery, number of emergency department visits, and number of primary care visits during the renal colic episode. To identify the factors associated with outcomes, both univariate and multivariable logistic regression models were used.

RESULTS

A total of 429 060 patients were included in the final analysis. Of those, 50.5% (216 747) had a CT scan as their initial imaging modality, 20% (84 672) had an US, and 3% (13 643) had both a CT and an US on the same day. Subsequent imaging was obtained in 40.7% of those who had a CT scan as the initial imaging, compared to 43% in those who had an US and 43% who had both an US at CT on the same day. Of those who initially had an US, 38% went on to have at least one CT scan during their renal colic episode, including those who had a CT on the same day as the initial US, while 62% were able to avoid a CT scan altogether. In contrast, 17% had a repeat CT after an initial CT at the time of presentation. The overall use of US increased from 15% to 31% during the study period. The length of the renal colic episode was slightly longer in those who had a CT first compared to US in multivariable models (ARR 1.005, 95% confidence interval [CI] 1.000-1.009); however, the time to surgery was less in those who had a CT first (ARR 0.831, 95% CI 0.807-0.856). Fewer emergency department and family physician visits were seen in those who had an initial CT.

CONCLUSIONS

In patients presenting with renal colic in Ontario, approximately half are having a CT done as the initial imaging modality despite US being the recommended imaging modality in uncomplicated renal colic presentations. While US use remains low, its use doubled during this study period, demonstrating an encouraging trend. Those who have an US done first are often able to avoid subsequent CT scans. Efforts should be made to further promote the use of US in those presenting with renal colic rather than CT when clinically indicated.

Variation in opioid filling after same-day breast surgery in Ontario, Canada: a population-based cohort study

BACKGROUND

Postoperative pain management practices in breast surgery are variable, with recent evidence that approaches for minimizing or sparing opioids can be successfully implemented. We describe opioid filling and predictors of higher doses in patients undergoing same-day breast surgery in Ontario, Canada.

METHODS

In this retrospective population-based cohort study, we used linked administrative health data to identify patients aged 18 years or older who underwent same-day breast surgery from 2012 to 2020. We categorized procedure types by increasing invasiveness of surgery: partial, with or without axillary intervention (P ± axilla); total, with or without axillary intervention (T ± axilla); radical, with or without axillary intervention (R ± axilla); and bilateral. The primary outcome was filling an opioid prescription within 7 or fewer days after surgery. Secondary outcomes were total oral morphine equivalents (OMEs) filled (mg, median and interquartile range [IQR]) and filling more than 1 prescription within 7 or fewer days after surgery. We estimated associations (adjusted risk ratios [RRs] and 95% confidence intervals [CIs]) between study variables and outcomes in multivariable models. We used a random intercept for each unique prescriber to account for provider-level clustering.

RESULTS

Of the 84 369 patients who underwent same-day breast surgery, 72% (n = 60 620) filled an opioid prescription. Median OMEs filled increased with invasiveness (P ± axilla = 135 [IQR 90-180] mg; T ± axilla = 135 [IQR 100-200] mg; R ± axilla = 150 [IQR 113-225] mg, bilateral surgery = 150 [IQR 113-225] mg; p < 0.0001). Factors associated with filling more than 1 opioid prescription were age 30-59 years (v. age 18-29 yr), increased invasiveness (RR 1.98, 95% CI 1.70-2.30 bilateral v. P ± axilla), Charlson Comorbidity Index ≥ 2 versus 0-1 (RR 1.50, 95% CI 1.34-1.69) and malignancy (RR 1.39, 95% CI 1.26-1.53).

INTERPRETATION

Most patients undergoing same-day breast surgery fill an opioid prescription within 7 days. Efforts are needed to identify patient groups where opioids may be successfully minimized or eliminated.

Endometriosis and cardiovascular disease: a population-based cohort study

BACKGROUND

Endometriosis, a prevalent condition among females of reproductive age, may be associated with increased risk of cardiovascular disease (CVD) through chronic inflammation and early menopause. The objective of this study was to estimate the association between endometriosis and subsequent risk of CVD.

METHODS

We conducted a population-based cohort study using administrative health data from Ontario residents from 1993 to 2015. We compared the incidence of CVD and cardiovascular health outcomes between females with endometriosis and 2 age-matched females without endometriosis. The primary outcome was hospital admission for CVD. Secondary outcomes included in-hospital CVD events of interest and emergency department visits for CVD. We used Cox proportional hazards models to estimate adjusted hazard ratios (HRs) between endometriosis and CVD events.

RESULTS

We identified 166 835 eligible patients with endometriosis and matched 333 706 patients without endometriosis. The mean age of those with endometriosis was 36.4 years. Patients with endometriosis had a higher incidence of hospital admission for CVD (195 admissions/100 000 person-years) compared with those without endometriosis (163 admissions/100 000 person-years). Similarly, the incidence of secondary CVD events was slightly higher among patients with endometriosis (292 cases/100 000 person-years) than among those without endometriosis (224 cases/100 000 person-years). Females with endometriosis had an increased risk of hospital admission (adjusted HR 1.14, 95% confidence interval [CI] 1.10-1.19) and secondary CVD events (adjusted HR 1.26, 95% CI 1.23-1.30).

INTERPRETATION

In this large, population-based study, endometriosis was associated with a small increased risk of CVD events. Future studies need to investigate potential etiological mechanisms and strategies to decrease long-term CVD risk in patients with endometriosis.

Cancer incidence among Canadian Veterans: A matched cohort study

INTRODUCTION

Occupational exposures related to military service may increase the risk of cancer for military Veterans, while high levels of fitness during service may decrease risk. However, few studies have compared this post-career cancer risk directly to the employed general population.

METHODS

This retrospective cohort study used linked administrative data. Canadian Armed Forces and Royal Canadian Mounted Police Veterans in Ontario, Canada were matched 1:4 on age, sex, geography, and community-level income to a group of non-Veterans most likely to have been employed during a period similar to the Veterans' military service. Cancer diagnoses were identified using the Ontario Cancer Registry.

RESULTS

During the study period, 642 of 30 576 included Veterans (2.1%) and 3408 of the 122 293 matched general population cohort (2.8%) experienced at least one cancer diagnosis. The crude rate of cancer was 153.5 per 100 000 person-years among Veterans vs. 205.9 per 100 000 person-years for the general population cohort. After adjusting for rurality and matching variables, Veterans had an 27% lower risk of developing any cancer than their matched comparators [hazard ratio = 0.73 (95% CI: 0.67-0.80)]. Among specific cancer types, the risk of lung and colorectal cancer was significantly lower for Veterans relative to the general population cohort; the risk of breast and prostate cancer was similar.

DISCUSSION

This study adds to the growing international evidence suggesting that risk of many cancers among Veterans is lower or similar to the general population. Further understanding of the complex relationships among occupational exposures, environmental factors, and lifestyle factors is needed.

Characterization of bromhexine and ambroxol in equine urine: effect of furosemide on identification and confirmation

The purpose of this study was two-fold: (1) to develop a simple and sensitive screening procedure for identifying and confirming bromhexine and ambroxol and, (2) to determine the effect of furosemide on the detection of bromhexine, ambroxol, or their metabolites in urine. Female horses (450-550 kg) treated with bromhexine or ambroxol (1 g, p.o.) were used. Urine samples were collected up to 48 h post-drug administration and analysed. Blind samples were used in evaluating the sensitivity of these methods and reproducibility of the results. Bromhexine and ambroxol were extensively metabolized in the horse. These agents and their respective metabolites were identified and confirmed using thin-layer chromatography (TLC) and gas chromatography-mass spectrometry (GC-MS), respectively. Hydroxy-bromhexine and desmethyl-bromhexine were major metabolites found to be unique to bromhexine-treated horses. These metabolites selectively absent from ambroxol-treated horse urine provide a chemical means to distinguish bromhexine from ambroxol administration in horses. These specific metabolites were similarly identified and confirmed in "blind" horse urine samples. The concomitant presence of furosemide (300 mg, i.v.) with bromhexine or ambroxol did not mask the presence of these agents or alter their metabolite profile. By application of the methods described in this study, bromhexine and ambroxol metabolites in horse urine can be easily identified and confirmed.