Defining the Longitudinal Risk of CIN 3+ for <CIN 2 Colposcopy for Patients Referred With High-Grade Cytology

OBJECTIVE

To determine the baseline and cumulative risk of cervical intraepithelial neoplasia (CIN)3 and invasive cervical cancer in participants referred to colposcopy with high-grade cytology and

METHODS

The authors linked administrative databases including cytology, pathology, cancer registries, and physician billing history to identify participants referred to colposcopy between January 2012 and December 2013 with high-grade cytology (atypical squamous cells [ASC]-H, high-grade squamous intraepithelial lesion [HSIL], invasive squamous cell carcinoma, adenocarcinoma, atypical glandular cells [AGC], adenocarcinoma in situ) and had

RESULTS

Among 4,168 women referred to colposcopy for ASC-H, HSIL, squamous cell carcinoma, or adenocarcinoma, the 3- and 5-year CIN3 incidence rates were 17.7%/20.0% no biopsy, 13.0%/15.1% negative biopsy, and 18.9%/20.0% low-grade squamous intraepithelial lesion (LSIL) biopsies. The 3- and 5-year incidences of invasive cancer were: 1.25%/1.68% no biopsy, 0.78%/1.04% negative biopsy, and 0%/0% LSIL biopsy. When the initial cytology was AGC/adenocarcinoma in situ (n = 944), the 3- and 5-year rates of CIN3 were 7.42%/8.39% no biopsy, 7.41%/9.26% negative biopsy, and 7.69%/7.69% LSIL biopsy. The invasive cancer rates were 1.12%/1.54% no biopsy, 0.46%/0.46% negative biopsy, and 0.0%/0.0% LSIL biopsy. By screening cytology, participants referred for HSIL had the highest 3- and 5-year rates of CIN3 (18.9% and 21%) compared with AGC (7.22%/8.28%) and ASC-H (15.5%/18%). The 3- and 5-year invasive cancer rates were 1.38%/1.75% HSIL, 0.85%/1.17% AGC, and 0.91%/1.36% ASC-H.

CONCLUSIONS

In participants referred for high-grade cytology where colposcopy shows Collapse

Key Words Collapse

MESH Headings

• Pregnancy
• Humans
• Female
• Uterine Cervical Neoplasms/diagnosis
• Uterine Cervical Neoplasms/epidemiology
• Uterine Cervical Neoplasms/pathology
• Colposcopy
• Adenocarcinoma in Situ
• Uterine Cervical Dysplasia/pathology
• Atypical Squamous Cells of the Cervix/pathology
• Carcinoma, Squamous Cell
• Squamous Intraepithelial Lesions
• Carcinoma in Situ
• Vaginal Smears
• Papillomavirus Infections/diagnosis
• Papillomaviridae

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Grants Collapse

Affiliation(s)

Sabrina Piedimonte Division of Gynecologic Oncology, University of Toronto, Toronto, Ontario, Canada
Kyle Tsang Cancer Prevention, Cancer Care Ontario, Toronto, Ontario, Canada
Nathaniel Jembere Cancer Prevention, Cancer Care Ontario, Toronto, Ontario, Canada
Joan Murphy Division of Gynecologic Oncology, University of Toronto, Trillium Health Partners, Mississauga, Ontario, Canada
Tina Karapetian Cancer Prevention, Cancer Care Ontario, Toronto, Ontario, Canada
Julia Gao Cancer Prevention, Cancer Care Ontario, Toronto, Ontario, Canada
Bronwen McCurdy Cancer Prevention, Cancer Care Ontario, Toronto, Ontario, Canada
Jocelyn Sacco Cancer Prevention, Cancer Care Ontario, Toronto, Ontario, Canada
Rachel Kupets Division of Gynecologic Oncology, Sunnybrook Hospital, Toronto, Ontario, Canada

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Measuring the impact of the COVID-19 pandemic on organized cancer screening and diagnostic follow-up care in Ontario, Canada: A provincial, population-based study

It is essential to quantify the impacts of the COVID-19 pandemic on cancer screening, including for vulnerable sub-populations, to inform the development of evidence-based, targeted pandemic recovery strategies. We undertook a population-based retrospective observational study in Ontario, Canada to assess the impact of the pandemic on organized cancer screening and diagnostic services, and assess whether patterns of cancer screening service use and diagnostic delay differ across population sub-groups during the pandemic. Provincial health databases were used to identify age-eligible individuals who participated in one or more of Ontario's breast, cervical, colorectal, and lung cancer screening programs from January 1, 2019-December 31, 2020. Ontario's screening programs delivered 951,000 (-41%) fewer screening tests in 2020 than in 2019 and volumes for most programs remained more than 20% below historical levels by the end of 2020. A smaller percentage of cervical screening participants were older (50-59 and 60-69 years) during the pandemic when compared with 2019. Individuals in the oldest age groups and in lower-income neighborhoods were significantly more likely to experience diagnostic delay following an abnormal breast, cervical, or colorectal cancer screening test during the pandemic, and individuals with a high probability of living on a First Nation reserve were significantly more likely to experience diagnostic delay following an abnormal fecal test. Ongoing monitoring and management of backlogs must continue. Further evaluation is required to identify populations for whom access to cancer screening and diagnostic care has been disproportionately impacted and quantify impacts of these service disruptions on cancer incidence, stage, and mortality. This information is critical to pandemic recovery efforts that are aimed at achieving equitable and timely access to cancer screening-related care.

The impact of the COVID-19 pandemic on the Ontario Cervical Screening Program, colposcopy and treatment services in Ontario, Canada: a population-based study

Objective

To describe the immediate impact of the COVID‐19 pandemic on cervical screening, colposcopy and treatment volumes in Ontario, Canada.

Design

Population‐based retrospective observational study.

Setting

Ontario, Canada.

Population

People with a cervix age of 21–69 years who completed at least one cervical screening cytology test, colposcopy or treatment procedure for cervical dysplasia between January 2019 and August 2020.

Methods

Administrative databases were used to compare cervical screening cytology, colposcopy and treatment procedure volumes before (historical comparator) and during the first 6 months of the COVID‐19 pandemic (March–August 2020).

Main outcome measures

Changes in cervical screening cytology, colposcopy and treatment volumes; individuals with high‐grade cytology awaiting colposcopy.

Results

During the first 6 months of the COVID‐19 pandemic, the monthly average number of cervical screening cytology tests, colposcopies and treatments decreased by 63.8% (range: −92.3 to −41.0%), 39.7% (range: −75.1 to −14.3%) and 31.1% (range: −43.5 to −23.6%), respectively, when compared with the corresponding months in 2019. Between March and August 2020, on average 292 (−51.0%) fewer high‐grade cytological abnormalities were detected through screening each month. As of August 2020, 1159 (29.2%) individuals with high‐grade screening cytology were awaiting follow‐up colposcopy.

Conclusions

The COVID‐19 pandemic has had a substantial impact on key cervical screening and follow‐up services in Ontario. As the pandemic continues, ongoing monitoring of service utilisation to inform system response and recovery is required. Future efforts to understand the impact of COVID‐19‐related disruptions on cervical cancer outcomes will be needed.

Tweetable abstract

COVID‐19 has had a substantial impact on cervical screening and follow‐up services in Ontario, Canada.

COVID‐19 has had a substantial impact on cervical screening and follow‐up services in Ontario, Canada.

Survival of Older Women With Cervical Cancer Based on Screening History

OBJECTIVE

A population-level retrospective cohort study was conducted to determine the influence of cervical screening history on the survival from cervical cancer in women 50 years or older.

METHODS

The study included women diagnosed with invasive cervical cancer in Ontario, Canada, between 2005 and 2012, who were followed for at least 4 years. Screening history was observed for the 5 years before diagnosis. Health care administrative databases were linked to determine demographic, affiliation with primary care physicians, stage (available 2010-2012), treatment, and survival data. Kaplan-Meier and multivariate analyses were carried out to evaluate the impact of cervical screening on overall survival (OS).

RESULTS

There were eligible 1,422 women diagnosed with invasive cervical cancer between 2005 and 2012 of whom 566 had been screened within the 5 years before diagnosis. There were 856 women who did not undergo screening within the 5 years before diagnosis. Unscreened women were more likely to present with locally advanced disease (69.3%) compared with the screened women (42.9%). Four-year OS was significantly greater in the screened group (79.9% vs 58.2%). In our univariate analysis, screening was significantly related to survival (hazard ratio = 2.1, p < .01). In our multivariate analysis after adjusting for age, treatment, affiliation with a primary care physician, and income, screening was still significantly associated with improved survival (hazard ratio = 1.5, p < .01).

CONCLUSIONS

Our results demonstrate a survival benefit to screening in women 50 years or older who are diagnosed with cervical cancer. Screening participation must be encouraged in women older than 50 years as rates decline in this age group.

Cervical Screening and Colposcopy Management of Women Age 24 and Under

OBJECTIVES

In 2012, Ontario's cervical cancer screening program changed the age of initial screening from 18 years of age to 21 and identified women aged 21-24 years as a special population whose cervical squamous intraepithelial lesions should be managed conservatively. In order to provide insight into these changes, we sought to examine patient, provider, and clinical characteristics of cervical cancer screening and colposcopy care in women aged 12-24 years.

METHODS

We conducted a retrospective population-based cohort study of all women in Ontario, aged 12-24 years, who underwent a Pap test between 2012 and 2014. Variables measured included, patient age, cytologic result of the index Pap test; colposcopy and definitive treatment within 1.5 years of the index Pap test; and carcinoma in situ (CIS) and invasive cervical cancer (ICC) 1.5 years after the index Pap test. Descriptive statistics were calculated for variables, and incidence rates per 100 000 women screened were calculated for CIS and ICC.

RESULTS

A total of 270 391 index Pap tests were performed. The majority of patients were between 18 and 24 years of age (12-17 y: 5.5%; 18-20 y: 24.3%; 21-24 y: 70.1%). Overall, 87.0% of Pap tests were normal, 6.9% of women underwent subsequent colposcopy, and 1.1% received any treatment. Of women with a high-grade result, 86.6% (n = 1279) underwent colposcopy and 42.8% (n=632) received any treatment. Of women with a low-grade result, 42.3% (n = 13 856) underwent colposcopy, and 6.0% (n = 1955) had any treatment. Age-standardized rates of CIS and ICC in were 161.5 and 1.0 per 100 000 women, respectively.

CONCLUSIONS

Despite the change in the screening guidelines, women under the age of 21 continue to be screened. This study highlights the low risk of ICC in women under age 25 and lays groundwork for re-examining screening guidelines for women in this age group. Furthermore, colposcopy referrals for women with a low-grade result on an index Pap test, and treatment of women under 24 years of age continue to be high. Future work must address the over-utilization of population-based screening, as well as factors related to adherence to screening guidelines.

Performance Indicators for Colposcopy in Ontario

OBJECTIVE

This study sought to evaluate the delivery of colposcopy assessments and treatments in Ontario from 2009 to 2017 according to specific performance measures, derived from guidelines on colposcopy use.

METHODS

This population-based descriptive analysis included screen-eligible women ages 21 to 69 in Ontario who underwent cervical screening between 2009 and 2017. Performance measures that describe the quality of colposcopy services in the province were calculated.

RESULTS

Five performance measures were used to assess the use of colposcopy in Ontario from 2009 to 2017. From 2013 to 2017, the percentage of women seen for colposcopy after a first diagnosis of atypical squamous cells of undetermined significance (ASCUS), without evidence of repeat cytology, remained stable, ranging from 5.9% to 6.3%. The median wait time to colposcopy for atypical glandular cells (AGC), atypical squamous cells (ASC-H), cannot rule out high-grade squamous intraepithelial lesions, and high-grade squamous intraepithelial lesions (HSIL), remained relatively stable from 2013 to 2017. In addition, the percentage of women with high-grade Pap test results who were seen in colposcopy within 6 months increased from 74.7% to 83.5%. The percentage of women who were not seen in follow-up within 12 months after treatment for cervical dysplasia remained stable, as did the percentage of women who discontinued colposcopy after three normal Pap test results following treatment for cervical dysplasia.

CONCLUSION

This study developed five performance indicators and used them to assess the delivery of colposcopic services in Ontario from 2009 to 2017. Performance indicators have previously been used effectively in the field of colorectal cancer screening to identify strengths and weaknesses in the delivery of healthcare services. This had never previously been done in colposcopy.

Co-morbid Non-communicable Diseases and Associated Health Service Use in African and Caribbean Immigrants with HIV

We sought to characterize non-communicable disease (NCD)-related and overall health service use among African and Caribbean immigrants living with HIV between April 1, 2010 and March 31, 2013. We conducted two population-based analyses using Ontario's linked administrative health databases. We studied 1525 persons with HIV originally from Africa and the Caribbean. Compared with non-immigrants with HIV (n = 11,931), African and Caribbean immigrants had lower rates of hospital admissions, emergency department visits and non-HIV specific ambulatory care visits, and higher rates of health service use for hypertension and diabetes. Compared with HIV-negative individuals from these regions (n = 228,925), African and Caribbean immigrants with HIV had higher rates of health service use for chronic obstructive pulmonary disease [rate ratio (RR) 1.78; 95% confidence interval (CI) 1.36-2.34] and malignancy (RR 1.20; 95% CI 1.19-1.43), and greater frequency of hospitalizations for mental health illness (RR 3.33; 95% CI 2.44-4.56), diabetes (RR 1.37; 95% CI 1.09-1.71) and hypertension (RR 1.85; 95% CI 1.46-2.34). African and Caribbean immigrants with HIV have higher rates of health service use for certain NCDs than non-immigrants with HIV. The evaluation of health services for African and Caribbean immigrants with HIV should include indicators of NCD care that disproportionately affect this population.

Estimates and predictors of health care costs of esophageal adenocarcinoma: a population-based cohort study

BACKGROUND

Esophageal adenocarcinoma (EAC) incidence is increasing rapidly. Esophageal cancer has the second lowest 5-year survival rate of people diagnosed with cancer in Canada. Given the poor survival and the potential for further increases in incidence, phase-specific cost estimates constitute an important input for economic evaluation of prevention, screening, and treatment interventions. The study aims to estimate phase-specific net direct medical costs of care attributable to EAC, costs stratified by cancer stage and treatment, and predictors of total net costs of care for EAC.

METHODS

A population-based retrospective cohort study was conducted using Ontario Cancer Registry-linked administrative health data from 2003 to 2011. The mean net costs of EAC care per 30 patient-days (2016 CAD) were estimated from the payer perspective using phase of care approach and generalized estimating equations. Predictors of net cost by phase of care were based on a generalized estimating equations model with a logarithmic link and gamma distribution adjusting for sociodemographic and clinical factors.

RESULTS

The mean net costs of EAC care per 30 patient-days were $1016 (95% CI, $955-$1078) in the initial phase, $669 (95% CI, $594-$743) in the continuing care phase, and $8678 (95% CI, $8217-$9139) in the terminal phase. Overall, stage IV at diagnosis and surgery plus radiotherapy for EAC incurred the highest cost, particularly in the terminal phase. Strong predictors of higher net costs were receipt of chemotherapy plus radiotherapy, surgery plus chemotherapy, radiotherapy alone, surgery alone, and chemotherapy alone in the initial and continuing care phases, stage III-IV disease and patients diagnosed with EAC later in a calendar year (2007-2011) in the initial and terminal phases, comorbidity in the continuing care phase, and older age at diagnosis (70-74 years), and geographic region in the terminal phase.

CONCLUSIONS

Costs of care vary by phase of care, stage at diagnosis, and type of treatment for EAC. These cost estimates provide information to guide future resource allocation decisions, and clinical and policy interventions to reduce the burden of EAC.

Effects of socioeconomic status on esophageal adenocarcinoma stage at diagnosis, receipt of treatment, and survival: A population-based cohort study

The incidence of esophageal adenocarcinoma (EAC) is increasing worldwide and has overtaken squamous histology in occurrence. We studied the impact of socioeconomic status (SES) on EAC stage at diagnosis, receipt of treatment, and survival. A population-based retrospective cohort study was conducted using Ontario Cancer Registry-linked administrative health data. Multinomial logistic regression was used to examine the association between SES (income quintile) and stage at EAC diagnosis and EAC treatment. Survival times following EAC diagnosis were estimated using Kaplan-Meier method. Cox proportional-hazards regression analysis was used to examine the association between SES and EAC survival. Between 2003–2012, 2,125 EAC cases were diagnosed. Median survival for the lowest-SES group was 10.9 months compared to 11.6 months for the highest-SES group; the 5-year survival was 9.8% vs. 15.0%. Compared to individuals in the highest-SES group, individuals in the lowest-SES category experienced no significant difference in EAC treatment (91.6% vs. 93.3%, P = 0.314) and deaths (78.9% vs. 75.6%, P = 0.727). After controlling for covariates, no significant associations were found between SES and cancer stage at diagnosis and EAC treatment. Additionally, after controlling for age, gender, urban/rural residence, birth country, health region, aggregated diagnosis groups, cancer stage, treatment, and year of diagnosis, no significant association was found between SES and EAC survival. Moreover, increased mortality risk was observed among those with older age (P = 0.001), advanced-stage of EAC at diagnosis (P < 0.001), and those receiving chemotherapy alone, radiotherapy alone, or surgery plus chemotherapy (P < 0.001). Adjusted proportional-hazards model findings suggest that there is no association between SES and EAC survival. While the unadjusted model suggests reduced survival among individuals in lower income quintiles, this is no longer significant after adjusting for any covariate. Additionally, there is an apparent association between SES and survival when considering only those individuals diagnosed with stage 0-III EAC. These analyses suggest that the observed direct relationship between SES and survival is explained by patient-level factors including receipt of treatment, something that is potentially modifiable.

Cost-effectiveness analysis of treatment with non-curative or palliative intent for hepatocellular carcinoma in the real-world setting

Hepatocellular carcinoma (HCC) presentation is heterogeneous necessitating a variety of therapeutic interventions with varying efficacies and associated prognoses. Poor prognostic patients often undergo non-curative palliative interventions including transarterial chemoembolization (TACE), sorafenib, chemotherapy, or purely supportive care. The decision to pursue one of many palliative interventions for HCC is complex and an economic evaluation comparing these interventions has not been done. This study evaluates the cost-effectiveness of non-curative palliative treatment strategies such as TACE alone or TACE+sorafenib, sorafenib alone, and non-sorafenib chemotherapy compared with no treatment or best supportive care (BSC) among patients diagnosed with HCC between 2007 and 2010 in a Canadian setting. Using person-level data, we estimated effectiveness in life years and quality-adjusted life years (QALYs) along with total health care costs (2013 US dollars) from the health care payer’s perspective (3% annual discount). A net benefit regression approach accounting for baseline covariates with propensity score adjustment was used to calculate incremental net benefit to generate incremental cost-effectiveness ratio (ICER) and uncertainty measures. Among 1,172 identified patients diagnosed with HCC, 4.5%, 7.9%, and 5.6%, received TACE alone or TACE+sorafenib, sorafenib, and non-sorafenib chemotherapy clone, respectively. Compared with no treatment or BSC (81.9%), ICER estimates for TACE alone or TACE+sorafenib was $6,665/QALY (additional QALY: 0.47, additional cost: $3,120; 95% CI: -$18,800-$34,500/QALY). The cost-effectiveness acceptability curve demonstrated that if the relevant threshold was $50,000/QALY, TACE alone or TACE+sorafenib, non-sorafenib chemotherapy, and sorafenib alone, would have a cost-effectiveness probability of 99.7%, 46.6%, and 5.5%, respectively. Covariates associated with the incremental net benefit of treatments are age, sex, comorbidity, and cancer stage. Findings suggest that TACE with or without sorafenib is currently the most cost-effective active non-curative palliative treatment approach to HCC. Further research into new combination treatment strategies that afford the best tumor response is needed.

A cross-sectional population-based study of breast cancer screening among women with HIV in Ontario, Canada

BACKGROUND

As women with HIV live longer, the need for age-appropriate breast cancer screening will increase. We compared rates of screening mammography among women with and without HIV.

METHODS

We used administrative health databases to identify all women in Ontario, Canada, who were eligible for screening mammography (aged 50 to 74 yr and no history of breast cancer) as of Apr. 1, 2011. We used multivariable log-binomial regression to compare the 2-year period prevalence of screening mammography in 2011 to 2013 among women with and without HIV and to examine the correlates of screening among women with HIV.

RESULTS

We identified 1 447 015 screen-eligible women, among whom 623 (0.04%) were women with HIV. Women with HIV were less likely to undergo screening than women without HIV (50.1% v. 63.4%, p < 0.001). Following multivariable adjustment, HIV-positive status was associated with significantly lower odds of undergoing mammography (adjusted prevalence ratio [PR] 0.83, 95% confidence interval [CI] 0.77-0.89). Compared with women with HIV receiving regular care from both a family physician and an HIV specialist, women with HIV receiving neither kind of care (adjusted PR 0.64, 95% CI 0.50-0.83) or predominantly specialist care (adjusted PR 0.77; 95% CI 0.60 to 0.97) were less likely to undergo screening mammography.

INTERPRETATION

Women with HIV are less likely to undergo breast cancer screening mammography than women without HIV. Addressing this disparity requires optimizing care delivery to ensure adequate provision of comprehensive primary care to people with HIV.

Self-rated health and mental health of lone fathers compared with lone mothers and partnered fathers: a population-based cross-sectional study

BACKGROUND

Lone parenthood is associated with poorer health; however, the vast majority of previous studies have examined lone mothers and only a few have focused on lone fathers. We aimed to examine the self-rated health and mental health status among a large population-based cross-sectional sample of Canadian lone fathers compared with both partnered fathers and lone mothers.

METHODS

We investigated differences in self-rated health and mental health among 1058 lone fathers compared with 20 692 partnered fathers and 5725 lone mothers using the Ontario component of the Canadian Community Health Survey (2001-2013). Multivariable logistic regression was used to compare the odds of poor/fair self-rated health and mental health between the study groups while adjusting for a comprehensive list of sociodemographic factors, stressors and lifestyle factors.

RESULTS

Lone fathers and lone mothers showed similar prevalence of poor/fair self-rated health (11.6% and 12.5%, respectively) and mental health (6.2% and 8.4%, respectively); the odds were similar even after multivariable adjustment. Lone fathers showed higher odds of poor/fair self-rated health (OR 1.53, 95% CI 1.07 to 2.17) and mental health (OR 2.09, 95% CI 1.26 to 3.46) than partnered fathers after adjustment for sociodemographic factors; however, these differences were no longer significant after accounting for stressors, including low income and unemployment.

CONCLUSIONS

In this large population-based study, lone fathers had worse self-rated health and mental health than partnered fathers and similarly poor self-rated health and mental health as lone mothers. Interventions, supports and social policies designed for single parents should also recognise the needs of lone fathers.

Provider- and patient-related determinants of diabetes self-management among recent immigrants: Implications for systemic change

OBJECTIVE

To examine provider- and patient-related factors associated with diabetes self-management among recent immigrants.

DESIGN

Demographic and experiential data were collected using an international survey instrument and adapted to the Canadian context. The final questionnaire was pretested and translated into 4 languages: Mandarin, Tamil, Bengali, and Urdu.

SETTING

Toronto, Ont.

PARTICIPANTS

A total of 130 recent immigrants with a self-reported diagnosis of type 2 diabetes mellitus who had resided in Canada for 10 years or less.

MAIN OUTCOME MEASURES

Diabetes self-management practices (based on a composite of 5 diabetes self-management practices, and participants achieved a score for each adopted practice); and the quality of the provider-patient interaction (measured with a 5-point Likert-type scale that consisted of questions addressing participants' perceptions of discrimination and equitable care).

RESULTS

A total of 130 participants in this study were recent immigrants to Canada from 4 countries of origin-Sri Lanka, Bangladesh, Pakistan, and China. Two factors were significant in predicting diabetes self-management among recent immigrants: financial barriers, specifically, not having enough money to manage diabetes expenses (P = .0233), and the quality of the provider-patient relationship (P = .0016). Participants who did not have enough money to manage diabetes were 9% less likely to engage in self-management practices; and participants who rated the quality of their interactions with providers as poor were 16% less likely to engage in self-management practices.

CONCLUSION

Financial barriers can undermine effective diabetes self-management among recent immigrants. Ensuring that patients feel comfortable and respected and that they are treated in culturally sensitive ways is also critical to good diabetes self-management.

Propensity score matching and complex surveys

Researchers are increasingly using complex population-based sample surveys to estimate the effects of treatments, exposures and interventions. In such analyses, statistical methods are essential to minimize the effect of confounding due to measured covariates, as treated subjects frequently differ from control subjects. Methods based on the propensity score are increasingly popular. Minimal research has been conducted on how to implement propensity score matching when using data from complex sample surveys. We used Monte Carlo simulations to examine two critical issues when implementing propensity score matching with such data. First, we examined how the propensity score model should be formulated. We considered three different formulations depending on whether or not a weighted regression model was used to estimate the propensity score and whether or not the survey weights were included in the propensity score model as an additional covariate. Second, we examined whether matched control subjects should retain their natural survey weight or whether they should inherit the survey weight of the treated subject to which they were matched. Our results were inconclusive with respect to which method of estimating the propensity score model was preferable. In general, greater balance in measured baseline covariates and decreased bias was observed when natural retained weights were used compared to when inherited weights were used. We also demonstrated that bootstrap-based methods performed well for estimating the variance of treatment effects when outcomes are binary. We illustrated the application of our methods by using the Canadian Community Health Survey to estimate the effect of educational attainment on lifetime prevalence of mood or anxiety disorders.

Comparing stage of diagnosis of cervical cancer at presentation in immigrant women and long-term residents of Ontario: a retrospective cohort study

BACKGROUND

Globally, cervical cancer is the fourth most common cancer in women and 7th most common cancer overall. Cervical cancer is highly preventable with screening. Previous work has shown that immigrants are less likely to undergo screening than nonimmigrants in Ontario, Canada. We examined whether immigrant women are more likely to present with later stage cervical cancer than long-term residents of the province.

METHODS

We conducted a retrospective matched cohort study of women with cervical cancer diagnosed between 2010 and 2014 using provincial administrative health data. We compared the odds of late-stage diagnosis between immigrants and long-term residents, adjusting for socioeconomic measures, comorbidities and health care use. The outcome of interest was stage of cervical cancer diagnosis, defined as early (stage I) or late (stages II-IV). We confirmed results with a cohort of women with cancer diagnosed between 2007 and 2012.

RESULTS

Complete staging data were available for 218 immigrants and 1348 matched long-term residents. We found no association between immigrant status and stage at diagnosis (adjusted odds ratio [OR] 0.94, 95% confidence interval [CI] 0.63-1.39). Factors that did show significant association with late-stage diagnosis were physician characteristics, whether a woman had previously undergone screening and had visited a gynecologist in the past 3 years. These results were echoed in the 2007-2012 cohort (immigrants v. long-term residents, OR 0.94, 95% CI 0.71-1.20).

INTERPRETATION

Our results show that being an immigrant is not associated with late-stage diagnosis of cervical cancer in Ontario. Programs broadly aimed at immigrants may require a targeted approach to address higher-risk subgroups.

Using physician billing claims from the Ontario Health Insurance Plan to determine individual influenza vaccination status: an updated validation study

BACKGROUND

Owing to the absence of a vaccination registry in Ontario, administrative data are currently the best available source to determine population-based individual-level influenza vaccination status. Our objective was to validate physician billing claims for influenza vaccination in the Ontario Health Insurance Plan database against the Canadian Community Health Survey.

METHODS

We used self-reported seasonal influenza vaccination status of Ontario residents surveyed between 2007 and 2009 as the reference standard. The survey responses were linked to physician claims database records to validate billing codes for influenza vaccination. We calculated sensitivity, specificity, positive predictive value and negative predictive value with 95% confidence intervals (CIs). We stratified the data by several covariates and comorbidities to determine stratum-specific performance characteristics. We used these estimates to adjust an estimate of influenza vaccine effectiveness for the 2010/11 influenza season.

RESULTS

For the 47 301 patients included in the analysis, the sensitivity for the billing codes was 49.8% (95% CI 49.0%-50.5%), specificity was 95.7% (95% CI 95.5%-96.0%), positive predictive value was 88.4% (95% CI 87.8%-89.0%) and negative predictive value was 74.5% (95% CI 74.0%-74.9%). Performance measures were optimized in patients aged 65 years and older, particularly those with comorbidities.

INTERPRETATION

Although administrative data have limitations for determining influenza vaccination status, owing to the high positive predictive value, they are well suited for self-controlled study designs that are often used to assess vaccine safety. For studies of coverage and effectiveness, restricting the cohort to patients aged 65 years and older will minimize misclassification bias. Performance characteristics from this study can be used to mitigate misclassification bias.

Use of Mental Health Services by Youths and Young Adults Before and During Correctional Custody: A Population-Based Study

OBJECTIVE

The authors measured use of mental health services among young people before and during incarceration.

METHODS

Administrative data were used to describe mental health services received by 13,919 youths and young adults (ages 12-24) while incarcerated in Ontario, Canada, correctional centers (physician visits, April 1, 2010-March 31, 2012) and, for a subset of the population, during the five years prior to incarceration.

RESULTS

Forty-two percent had a mental health-related visit during incarceration. Thirty-five percent had no mental health contact for five years before the beginning of the correctional episode. Forty percent of individuals with schizophrenia had a psychiatric hospitalization in the year before entering custody.

CONCLUSIONS

For one-third of young people with a mental health visit while incarcerated, the visit was the first mental health contact in at least five years. Yet high use of psychiatric services before entering custody among individuals with schizophrenia may indicate gaps in continuity of mental health care.

Identification of the physician workforce providing palliative care in Ontario using administrative claims data

BACKGROUND

Little is known about the physician workforce providing palliative care in Canada, and in Ontario specifically. We developed an algorithm to identify palliative care physicians using administrative claims data and validated it against a reference sample. We then applied the algorithm to all general practitioners/family physicians (GP/FPs) in the province of Ontario to describe and quantify those identified by the algorithm.

METHODS

W e reviewed Ontario Health Insurance Plan claims from Jan. 1, 2008, to Dec. 31, 2011, to determine each physician's proportion of claims that were for palliative care. We empirically selected a data-driven cut-off, whereby physicians whose proportion of palliative care claims was above the threshold were defined as palliative care physicians. We validated the cut-off against a reference sample of physicians who self-identified as providing mostly palliative care in a study-specific survey. We then applied this algorithm to all GP/FPs in the province.

RESULTS

We empirically selected 10% as the cut-off for the proportion of palliative care claims. This threshold had exceptional specificity and positive predictive value (97.8% and 90.5%, respectively) and adequate sensitivity (76.0%) when compared with the reference sample (n = 118). When applied to all GP/FPs in the province, the algorithm identified 276 practising mostly palliative care. Of these, 135 (48.9%) were women, 265 (96.0%) practised in urban locations, and 145 (52.5%) worked part time.

INTERPRETATION

Our algorithm readily identified and quantified the workforce of palliative care physicians in Ontario. Such a tool has numerous applications for both health service planners and researchers.

A population-based study of the extent of colorectal cancer screening in men with HIV

Background

Because of the increased life-expectancy of persons with HIV, the need for age-appropriate colorectal cancer screening among these patients will increase. We examined rates of colorectal cancer screening among HIV-infected men aged 50 to 65 years.

Methods

We used Ontario’s administrative databases to identify all men between the ages of 50 and 65 years who were alive on April 1, 2007, and identified HIV-infected men using a validated case-finding algorithm. We excluded men with a history of colorectal cancer, anal cancer, inflammatory bowel disease and any colorectal investigation in the preceding five-years, and used multivariable regression to compare rates of colorectal cancer screening between men with and without HIV during five years of follow-up.

Results

We identified 743,801 men between the ages of 50 and 65 years, of whom 1,432 (0.19%) were HIV-infected. The proportions of men with and without HIV who underwent any screening during the 5-year follow up period were 49.1% (95% CI 46.5% to 51.7%) and 41.4% (95% CI 41.3% to 41.5%), respectively. Compared with HIV-negative men, men with HIV had lower rates of fecal occult blood testing [adjusted rate ratio (aRR) 0.74; 95% confidence interval (CI) 0.63 to 0.87] and barium-enema radiography (aRR 0.66; 95% CI 0.39 to 1.12), but higher rates of colonoscopy (aRR 1.24; 95% CI 1.13 to 1.37), flexible sigmoidoscopy (aRR 1.72; 95% CI 1.28 to 2.30) and rigid sigmoidoscopy (aRR 2.98; 95% CI 2.26 to 3.93).

Conclusion

As with the general population of men aged 50 to 65 years, less than half of the population of men with HIV received colorectal cancer screening. Strategies are required to improve uptake of this intervention.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-015-0711-9) contains supplementary material, which is available to authorized users.

Osteoporosis management and fractures in the Métis of Ontario, Canada

Half of Métis citizens, compared to less than 10 % of the general population of Ontario, reside in northern regions, with little access to bone mineral density (BMD) testing. Métis citizens had lower sex-specific and age-standardized rates of BMD testing, yet similar rates of fracture (both sexes) and pharmacotherapy (women only).

PURPOSE

To examine osteoporosis management and common osteoporosis-related fractures among Métis citizens compared to the general population of older adults residing in Ontario.

METHODS

We linked healthcare (medical and pharmacy) utilization and administrative (demographic) databases with the Métis Nation of Ontario citizenship registry to estimate osteoporosis management (bone mineral density [BMD] testing, pharmacotherapy) and fractures (hip, humerus, radius/ulna) among adults aged ≥50 years, from April 1, 2006 to March 31, 2011. Pharmacotherapy data were limited to residents aged ≥65 years. Sex-specific and age-standardized rates were compared between the Métis and the general population. Multivariable logistic regression was used to compare rates of BMD testing after controlling for differences in age and region of residence between the Métis and the general population.

RESULTS

We studied 4219 Métis citizens (55 % men), and 140 (3 %) experienced a fracture. Half of Métis citizens, compared to less than 10 % of the general population of Ontario, resided in northern regions. We identified significantly lower sex-specific and age-standardized rates of BMD testing among Métis compared to the general population, yet found little difference in fracture rates (both sexes) or pharmacotherapy (women only). Differences in BMD testing disappeared after adjusting for region of residence among women yet remained significant among men.

CONCLUSIONS

Despite finding significantly lower rates of osteoporosis management among men, Métis men and women were found to have similar age-standardized fracture rates to the general population.

Influence of socioeconomic status on survival of hepatocellular carcinoma in the Ontario population; a population-based study, 1990-2009

Background

Research has shown that people from higher socioeconomic status (SES) have better hepatocellular carcinoma (HCC) survival outcomes, although no such research has been carried out in Canada. We aimed to assess if an association between SES and HCC survival existed in the Canadian context.

Methodology/Prinicpal Findings

We conducted a population-based cohort study linking HCC cases identified in the Ontario Cancer Registry between 1990 and 2009 to administrative and hospital data. Logistic regression and chi-squared tests were used to evaluate associations between SES (income quintile) and covariates. The Kaplan-Meier method was used to estimate survival. Sequential analysis of the proportional-hazards models were used to determine the association between SES and HCC survival controlling for potential prognostic covariates. During the period 1990–2009, 5,481 cases of HCC were identified. A significant association was found between SES and curative treatment (p = 0.0003), but no association was found between SES and non-curative treatment (p = 0.064), palliative treatment (p = 0.680), or ultrasound screening (p = 0.615). The median survival for the lowest SES was 8.5 months, compared to 8.8 months for the highest SES group. The age- and sex-adjusted proportional-hazards model showed statistically significant difference in HCC survival among the SES groups, with hazard ratio 0.905 (95% confidence intervals 0.821, 0.998) when comparing highest to lowest SES group. Further adjustments indicated that potentially curative treatment was the likely explanation for the association between SES and HCC survival.

Conclusions/Significance

Our findings suggest that a 10% HCC survival advantage exists for the higher SES groups. This association between SES and HCC survival is most likely a reflection of lack of access to care for low SES groups, revealing inequities in the Canadian healthcare system.