Measuring the impact of COVID-19 on cancer survival using an interrupted time series analysis.

BACKGROUND: Few studies have investigated the impact of the COVID-19 pandemic on cancer survival. Those studies that have included pandemic vs prepandemic comparisons can mask differences during different periods of the pandemic such as COVID-19 waves. The objective of this study was to investigate the impact of the COVID-19 pandemic on cancer survival using an interrupted time series analysis and to identify time points during the pandemic when observed survival deviated from expected survival. METHODS: A retrospective population-based cohort study that included individuals diagnosed with cancer between January 2015 and September 2021 from Manitoba, Canada, was performed. Interrupted time series analyses with Royston-Parmar models as well as Kaplan-Meier survival estimates and delta restricted mean survival times at 1 year were used to compare survival rates for those diagnosed before and after the pandemic. Analyses were performed for 11 cancer types. RESULTS: Survival at 1 year for most cancer types was not statistically different during the pandemic compared with prepandemic except for individuals aged 50-74 years who were diagnosed with lung cancer from April to June 2021 (delta restricted mean survival times = -31.6 days, 95% confidence interval [CI] = -58.3 to -7.2 days). CONCLUSIONS: With the exception of individuals diagnosed with lung cancer, the COVID-19 pandemic did not impact overall 1-year survival in Manitoba. Additional research is needed to examine the impact of the pandemic on long-term cancer survival.

Cancer incidence during the COVID-19 pandemic by region of residence in Manitoba, Canada: A cancer registry-based interrupted time series study.

INTRODUCTION: Health care in Manitoba, Canada is divided into five regions, each with unique geographies, demographics, health care access, and health status. COVID-19-related restrictions and subsequent responses also differed by region. To understand the impact of the pandemic on cancer incidence in the context of these differences, we examined age-standardized cancer incidence rates by region over time before and after the COVID-19 pandemic. METHODS: We used a population-based quasi-experimental study design, population-based data, and an interrupted time series analysis to examine the rate of new cancer diagnoses before (January 2015 until December 2019) and after the start of COVID-19 and the interventions implemented to mitigate its impact (April 2020 until December 2021) by region. RESULTS: Overall cancer incidence differed by region and remained lower than expected in Winnipeg (4.6% deficit, 447 cases), Prairie Mountain (6.9% deficit, 125 cases), and Southern (13.0% deficit, 238 cases). Southern was the only region that had a significantly higher deficit in cases compared to Manitoba (ratio 0.92, 95% CI 0.86, 0.99). Breast and colorectal cancer incidence decreased at the start of the pandemic in all regions except Northern. Lung cancer incidence decreased in the Interlake-Eastern region and increased in the Northern region. Prostate cancer incidence increased in Interlake-Eastern. CONCLUSIONS: The impact of the COVID-19 pandemic on cancer incidence differed by region. The deficit in the number of cases was largest in the southern region and was highest for breast and prostate cancers. Cancer incidence did not significantly decrease in the most northern, remote region.

New Cancer Diagnoses Before and During the COVID-19 Pandemic.

Importance: Disruptions to health care during the COVID-19 pandemic may have led to missed cancer diagnoses. It is critical to evaluate the association between the COVID-19 pandemic and cancer incidence to address public and patient anxiety, inform recovery efforts, and identify strategies to reduce the system's vulnerability to future disruptions. Objective: To examine the association between the COVID-19 pandemic and cancer incidence in Manitoba, Canada. Design, Setting, and Participants: A population-based cross-sectional study design was conducted using data from the Manitoba Cancer Registry and an interrupted time-series analysis. All individuals diagnosed with cancer in Manitoba, Canada, from January 1, 2015, until December 31, 2021, were included. Individuals diagnosed with breast, colon, rectal, or lung cancer were grouped by age as follows: younger than 50 years, 50 to 74 years, and 75 years and older. Exposures: COVID-19 pandemic. Main Outcomes and Measures: Age-standardized cancer incidence rates and the estimated cumulative difference between the number of cases in the absence of COVID-19 and observed (fitted) number of cancer cases. Results: A total of 48 378 individuals were included. The median (IQR) age at diagnosis was 68 (59-77) years and 23 972 participants (49.6%) were female. In April 2020, there was a 23% decrease in overall cancer incidence. Cancer incidence decreased by 46% for breast, 35% for colon, 47% for rectal, 50% for head and neck, 65% for melanoma, and 33% for endocrine cancer diagnoses and increased by 12% for hematological cancer diagnoses and 8% for diagnoses of cancers with an unknown primary site. Lung cancer incidence remained stable until December 2020 when it decreased by 11%. Brain and central nervous system and urinary cancer diagnoses decreased consistently over time from April 2020 to December 2021 by 26% and 12%, respectively. No association was observed with gynecologic (1% increase), other digestive (1% decrease), or pancreatic (7% increase) cancer incidence. As of December 2021, Manitoba had an estimated deficit of 692 (5.3%) cancers. The largest estimated deficits were for breast (273 cases, 14.1% deficit), colon (133 cases, 12.2% deficit), and lung cancers (132 cases, 7.6% deficit). Conclusions and Relevance: In this study, the COVID-19 pandemic was associated with an initial decrease in cancer diagnosis incidence followed by a recovery for most cancer sites. However, the cumulative deficit for some cancers with high fatality needs immediate attention.

Evaluating the impact of the COVID-19 pandemic on cancer screening in a central Canadian province.

We evaluated the impact of COVID-19 on cancer screening in Manitoba, Canada using an interrupted time series (ITS) design and data from Manitoba's population-based, organized cancer screening programs from April 2020 to August 2021. In June 2020 (breast screening was suspended during April and May 2020), there was a 54% decrease between the predicted (i.e., observed data produced from regression models) and expected (i.e., counterfactual values produced for the COVID-19 period by assuming COVID-19 did not occur) number of screening mammograms (ratio = 0.46, 95% Confidence Interval (CI) 0.28-0.64). By December 2020, there was no significant difference between predicted and expected number of screening mammograms (ratio = 0.95, 95% CI 0.80-1.10). In April 2020, there was an 83% decrease in the number of Pap tests (ratio = 0.17, 95% CI 0.04-0.30). By January 2021, there was no significant difference between predicted and expected number of Pap tests (ratio = 0.93, 95% CI 0.81-1.06). In April 2020, there was an 81% decrease in the number of screening program fecal occult blood tests (FOBTs) (ratio = 0.19, 95% CI 0.0-0.44). By September 2020, there was no significant difference between predicted and expected number of FOBTs (ratio = 0.95, 95% CI 0.65-1.24). The estimated cumulative deficit (i.e., backlog) from April 2020 to August 2021 was 17,370 screening mammograms, 22,086 Pap tests, and 5253 screening program FOBTs. Overall, screening programs adapted quickly to the COVID-19 pandemic. Additional strategies may be needed to address remaining backlogs.

World Health Organization growth standards: How do Canadian children measure up?

BACKGROUND: World Health Organization (WHO) growth standards for children aged 0 to 5 years describe growth under optimal conditions and were adopted for use in Canada in 2012. We are seeking to validate these charts in a well-characterized, longitudinal cohort of healthy, Canadian youngsters, assess tracking over time, and evaluate the prognostic implications of early growth. METHODS: Data from 2,795 mother-infant dyads from the CHILD birth cohort were classified by feeding modality at 6 months as exclusively breastfed, partially breastfed, or formula-fed. WHO z-scores (z) were calculated at birth, 3 months, 1 year, and 3 years. Receiver operator characteristics (ROC) assessed the predictive performance of early weight (WT), weight-for-length (WfL), or body mass index (BMI) z-scores for overweight/obesity at 3 years. RESULTS: Compared to WHO standards, Canadian children at birth had lower median WfLz (-0.73) and BMIz (-0.29), with more positive scores by 3 years (WfLz=BMIz=0.58). At both 1 and 3 years, formula feeding was associated with higher scores than breastfeeding, even after regression adjustment for covariates. Head circumference z-score was typically positive at all times and regardless of feeding modality. At 1 year, ROC area under the curve was 0.79 for WTz, WfLz, and BMIz, and BMIz>0.88 identified children with increased risk of overweight/obesity (BMIz >2) at age 3 years (20.3% versus 3.0%, P<0.001). CONCLUSIONS: Compared to WHO growth charts, Canadian children at 3 years show an upward shift in BMIz and WfLz, particularly when formula-fed. Infant growth parameters may identify infants with increased risk of overweight/obesity at age 3 years; early recognition may allow targeting infants at higher risk.

Evaluating the Impact of the COVID-19 Pandemic on New Cancer Diagnoses and Oncology Care in Manitoba.

Individuals with cancer are vulnerable to infection with SARS-CoV-2, the virus causing COVID-19. Physical distancing, the reallocation of health care resources, and the implementation of procedures to reduce the spread of COVID-19 may also have serious consequences for people with cancer. We evaluated the impact of COVID-19 on new cancer diagnoses and oncology care in Manitoba, Canada using an interrupted time series design and data from the Manitoba Cancer Registry and CancerCare Manitoba's (CCMB) electronic medical record. In April 2020, there was a 23% decrease in new cancer diagnoses, a 21% decrease in pathology reports, and a 43% reduction in surgical resections. There was no difference in new cancer diagnoses by August 2020, surgery by July 2020, and pathology reports by September 2020. From April 2020 to June 2021, there was a 13% decrease in radiotherapy (RT) fractions, an 18% decrease in UCC visits, and a 52% decrease in in-person visits. There was no change in intravenous chemotherapy visits per month, first RT visits, or overall patient visits. The impact of COVID-19 on shifts in the stage at diagnosis and survival will be assessed in future analyses.

Colorectal Cancer Surgery Quality in Manitoba: A Population-Based Descriptive Analysis.

Unwarranted clinical variation in healthcare impacts access, productivity, performance, and outcomes. A strategy proposed for reducing unwarranted clinical variation is to ensure that population-based data describing the current state of health care services are available to clinicians and healthcare decision-makers. The objective of this study was to measure variation in colorectal cancer surgical treatment patterns and surgical quality in Manitoba and identify areas for improvement. This descriptive study included individuals aged 20 years or older who were diagnosed with invasive cancer (adenocarcinoma) of the colon or rectum between 1 January 2010 and 31 December 2014. Laparoscopic surgery was higher in colon cancer (24.1%) compared to rectal cancer (13.6%). For colon cancer, the percentage of laparoscopic surgery ranged from 12.9% to 29.2%, with significant differences by regional health authority (RHA) of surgery. In 86.1% of colon cancers, ≥12 lymph nodes were removed. In Manitoba, the negative circumferential resection margin for rectal cancers was 96.9%, and ranged from 96.0% to 100.0% between RHAs. The median time between first colonoscopy and resection was 40 days for individuals with colon cancer. This study showed that high-quality colorectal cancer surgery is being conducted in Manitoba along with some variation and gaps in quality. As a result of this work, a formal structure for ongoing measuring and reporting surgical quality has been established in Manitoba. Quality improvement initiatives have been implemented based on these findings and periodic assessments of colorectal cancer surgery quality will continue.

Correction: Ratnayake et al. Assessment of Breast Cancer Surgery in Manitoba: A Descriptive Study. Curr. Oncol. 2021, 28, 581-592.

The authors wish to make a correction to this paper due to a minor change in indicator definition [...].

A population-based study to develop juvenile arthritis case definitions for administrative health data using model-based dynamic classification.

BACKGROUND: Previous research has shown that chronic disease case definitions constructed using population-based administrative health data may have low accuracy for ascertaining cases of episodic diseases such as rheumatoid arthritis, which are characterized by periods of good health followed by periods of illness. No studies have considered a dynamic approach that uses statistical (i.e., probability) models for repeated measures data to classify individuals into disease, non-disease, and indeterminate categories as an alternative to deterministic (i.e., non-probability) methods that use summary data for case ascertainment. The research objectives were to validate a model-based dynamic classification approach for ascertaining cases of juvenile arthritis (JA) from administrative data, and compare its performance with a deterministic approach for case ascertainment. METHODS: The study cohort was comprised of JA cases and non-JA controls 16 years or younger identified from a pediatric clinical registry in the Canadian province of Manitoba and born between 1980 and 2002. Registry data were linked to hospital records and physician billing claims up to 2018. Longitudinal discriminant analysis (LoDA) models and dynamic classification were applied to annual healthcare utilization measures. The deterministic case definition was based on JA diagnoses in healthcare use data anytime between birth and age 16 years; it required one hospitalization ever or two physician visits. Case definitions based on model-based dynamic classification and deterministic approaches were assessed on sensitivity, specificity, and positive and negative predictive values (PPV, NPV). Mean time to classification was also measured for the former. RESULTS: The cohort included 797 individuals; 386 (48.4 %) were JA cases. A model-based dynamic classification approach using an annual measure of any JA-related healthcare contact had sensitivity = 0.70 and PPV = 0.82. Mean classification time was 9.21 years. The deterministic case definition had sensitivity = 0.91 and PPV = 0.92. CONCLUSIONS: A model-based dynamic classification approach had lower accuracy for ascertaining JA cases than a deterministic approach. However, the dynamic approach required a shorter duration of time to produce a case definition with acceptable PPV. The choice of methods to construct case definitions and their performance may depend on the characteristics of the chronic disease under investigation.

Assessment of Breast Cancer Surgery in Manitoba: A Descriptive Study.

BACKGROUND: Variation in breast cancer surgical practice patterns can lead to poor clinical outcomes. It is important to measure and reduce variation to ensure all women diagnosed with breast cancer receive equitable, high-quality care. A population-based assessment of the variation in breast cancer surgery treatment and quality has never been conducted in Manitoba. The objective of this study was to assess the variation in surgical treatment patterns, quality of care, and post-operative outcomes for women diagnosed with invasive breast cancer. METHODS: This descriptive study used data from the Manitoba Cancer Registry, Hospital Discharge Abstracts Database, Medical Claims, Manitoba Health Insurance Registry, and Statistics Canada. The study included women in Manitoba aged 20+ and diagnosed with invasive breast cancer between 1 January 2010 and 31 December 2014. RESULTS: Axillary lymph node dissection (ALND) for node-negative disease ranged from 11.8% to 33.3%, timeliness (surgery within 30 days of consult) ranged from 33.3% to 60.2%, and re-excision ranged from 14.7% to 24.6% between health authorities. Women who underwent breast-conserving surgery had the shortest median length of stay and women who underwent mastectomy with immediate reconstruction had the longest median length of stay. In-hospital post-operative complications were higher among women who received mastectomy with immediate reconstruction (9.9%). CONCLUSION: Variation in surgical treatment, quality, and outcomes exist in Manitoba. The findings from this study can be used to inform cancer service delivery planning, quality improvement efforts, and policy development. Influencing data-driven change at the health system level is paramount to ensuring Manitobans receive the highest quality of care.

Adverse childhood experiences are associated with an increased risk of obesity in early adolescence: a population-based prospective cohort study.

OBJECTIVE: To determine whether adverse childhood experiences were associated with weight gain and obesity risk in adolescence. METHODS: We analyzed data from 6942 adolescents followed between 9 and 13 years of age in the Growing Up in Ireland cohort study. The main exposures were 14 adverse childhood experiences, 4 of which were included in the Adverse Childhood Experience (ACE) study. The primary outcome was incident overweight and obesity at 13 years. Secondary outcomes included prevalent overweight/obesity and weight gain. RESULTS: More than 75% of the youth experienced an adverse experience and 17% experienced an ACE-specific experience before 9 years. At 13 years, 48% were female and 31.4% were overweight or obese. After adjusting for confounding, exposure to any adverse experience was associated with prevalent overweight/obesity (aOR: 1.56; 1.19-2.05) and incident overweight/obesity (adjusted IRR: 2.15; 95% CI: 1.37-3.39), while exposure to an ACE-specific exposure was associated weight gain (BMI Z score change = 0.202; 95% CI: 0.100-0.303). A significant interaction between income and adverse childhood experiences was observed for both incident overweight/obesity and weight gain (BMI Z change: -0.046; 95% CI: -0.092 to 0.000). CONCLUSIONS: Adverse childhood experiences and low income interact and independently predict obesity risk in early adolescence.

Biological and socioeconomic determinants of prediabetes in youth: an analysis using 2007 to 2011 Canadian Health Measures Surveys.

OBJECTIVES: To describe rates of prediabetes among youth in Canada and the associated social and biological characteristics. METHODS: We analyzed the cross-sectional data from the first (2007-2009) and second (2009-2011) cycles of the Canadian Health Measures Survey (CHMS) for youth aged 6-19 years. Prediabetes was defined using the glycated hemoglobin (A1C) guidelines set out by the American Diabetes Association (ADA) and the Canadian Diabetes Association (CDA) of A1C ranges 5.7-6.4% (38.8-46.4 mmol/mol) and 6.0-6.4% (42.1-46.4 mmol/mol), respectively. RESULTS: An elevated A1C was observed in 22.8% of our sample (n = 3449) based on the ADA definition and 5.2% of youth using the CDA definition. Independent predictors in a fully adjusted model for prediabetes were non-White (odds ratio (OR) 2.62: 95% Confidence intervals 2.05-3.35), obese (OR 1.53: 1.19-1.96), less physically active youth (0.97: 0.95-0.99), and parents with high school education or less (1.34: 1.02-1.74). Moreover, significant regional variations were noted with higher rates for all regions except Ontario. CONCLUSION: Prediabetes is relatively common in Canada and associated with common biologic and socioeconomic factors. Importantly, regular physical activity was significantly associated with reduced odds of prediabetes. Targeted screening and continued emphasis on physical activity may help curb the increasing rates of prediabetes.

Estimating multimorbidity prevalence with the Canadian Chronic Disease Surveillance System. / Estimation de la prévalence de la multimorbidité au moyen du Système canadien de surveillance des maladies chroniques.

INTRODUCTION: The Public Health Agency of Canada's Canadian Chronic Disease Surveillance System (CCDSS) uses a validated, standardized methodology to estimate prevalence of individual chronic diseases, such as diabetes. Expansion of the CCDSS for surveillance of multimorbidity, the co-occurrence of two or more chronic diseases, could better inform health promotion and disease prevention. The objective of this study was to assess the feasibility of using the CCDSS to estimate multimorbidity prevalence. METHODS: We used administrative health data from seven provinces and three territories and five validated chronic conditions (i.e. cardiovascular disease, respiratory disease, mental illness, hypertension and diabetes) to estimate multimorbidity prevalence. We produced age-standardized (using Canada's 1991 population) and age-specific estimates for two multimorbidity definitions: (1) two or more conditions, and (2) three or more conditions from the five validated conditions, by sex, fiscal year and geography. RESULTS: Among Canadians aged 40 years and over in the fiscal year 2011/12, the prevalence of two or more and three or more chronic conditions was 26.5% and 10.2%, respectively, which is comparable to other estimates based on administrative health data. The increase in multimorbidity prevalence with increasing age was similar across provinces. The difference in prevalence for males and females varied by province and territory. We observed substantial variation in estimates over time. Results were consistent for the two definitions of multimorbidity. CONCLUSION: The CCDSS methodology can produce comparative estimates of multimorbidity prevalence across provinces and territories, but there are challenges in using it to estimate temporal trends. Further expansion of the CCDSS in the number and breadth of validated case definitions will improve the accuracy of multimorbidity surveillance for the Canadian population.

INTRODUCTION: Le Système canadien de surveillance des maladies chroniques (SCSMC) de l'Agence de la santé publique du Canada utilise une méthode validée et normalisée pour estimer la prévalence des maladies chroniques, par exemple le diabète. L'élargissement de la portée du SCSMC pour inclure la surveillance de la multimorbidité et de la présence concomitante de deux maladies chroniques ou plus pourrait mieux guider la promotion de la santé et la prévention des maladies. L'objectif de notre étude était de déterminer s'il était possible de recourir au SCSMC pour estimer la prévalence de la multimorbidité. MÉTHODOLOGIE: Nous avons utilisé les données administratives sur la santé de sept provinces et de trois territoires portant sur cinq affections chroniques validées (maladies cardiovasculaires, maladies respiratoires, maladies mentales, hypertension et diabète) pour estimer la prévalence de la multimorbidité. Nous avons produit des estimations normalisées selon l'âge et spécifiques selon l'âge (à l'aide des données démographiques canadiennes de 1991) pour deux définitions de la multimorbidité, soit deux affections ou plus ou trois affections ou plus sur les cinq affections validées, selon le sexe, la période et la zone géographique. RÉSULTATS: Au cours de l'exercice 2011-2012, la prévalence d'au moins deux et d'au moins trois affections chroniques chez les Canadiens de 40 ans ou plus se situait à respectivement 26,5 % et 10,2 %, ce qui est comparable à d'autres estimations faites à partir des données administratives sur la santé. L'augmentation de la prévalence de la multimorbidité avec l'âge était similaire dans toutes les provinces. Les différences de prévalence entre hommes et femmes variaient selon les provinces et territoires. Nous avons également observé une variation importante des estimations au fil des années. Les résultats obtenus étaient comparables pour les deux définitions de la multimorbidité. CONCLUSION: La méthodologie du SCSMC permet de produire des estimations comparatives de la prévalence de la multimorbidité dans l'ensemble des provinces et des territoires, mais son utilisation pour estimer les variations temporelles pose des difficultés. L'augmentation du nombre et de la portée des définitions de cas validées dans le SCSMC permettra d'améliorer l'exactitude de la surveillance de la multimorbidité auprès de la population canadienne.