Adherence to cancer screening guidelines across Canadian provinces: an observational study

Changes in mammography screening in Ontario and Alberta following national guideline dissemination: an interrupted time series analysis

Background: In November 2011, the Canadian Task Force on Preventive Health Care released guidelines for screening women at average breast cancer risk. Weak recommendations (framed using GRADE methodology) were made for screening women aged 50 to 74 years every two to three years, and for not screening women aged 40 to 49 years. Methods: We conducted an interrupted time series analysis using administrative data to examine bilateral mammography use before and after a release of a national breast screening guideline. Women aged 40 to 74 years living in Ontario or Alberta from 30th November 2008 to 30th November 2014 were included. Strata included age, region of residence, neighbourhood income quintile, immigration status, and education level. Results: In both provinces, mammography use rates were lower in the post-intervention period (527 vs. 556 and 428 vs. 465/1000 women in Ontario and Alberta, respectively). In Ontario, mammography trends decreased following guideline release to align with recommendations for women aged 40 to 74 (decrease of 2.21/1000 women, SE 0.26/1000, p<0.0001). In Alberta, mammography trends decreased for women aged 40 to 49 years (3/1000 women, SE 0.32, p<0.001) and 50 to 69 (2.9/1000 women, SE 0.79, p<0.001), but did not change for women aged 70 to 74 (0.7/1000 women, SE 1.23, p=0.553). In both provinces, trends in mammography use rates were sustained for up to three years after guideline release. Conclusions: We observed a decrease in screening for women aged 40-49. Additional research to explore whether shared decision making was used to optimize guideline-concordant screening for women aged 50-74 is needed.

Incidence and Mortality of Prostate Cancer in Canada during 1992-2010

In Canada, prostate cancer is the most common reportable malignancy in men. We assessed the temporal trends of prostate cancer to gain insight into the geographic incidence and mortality trends of this disease. Three independent population-based cancer registries were used to retrospectively analyze demographic data on Canadian men diagnosed with prostate cancer and men who died of prostate cancer between the years of 1992 and 2010. The incidence and mortality rates were calculated at the provincial, city, and forward sortation area (FSA) postal code levels by using population counts that were obtained from the Canadian Census of Population. The Canadian average incidence rate was 113.57 cases per 100,000 males. There has been an overall increasing trend in crude prostate cancer incidence between 1992 and 2010 with three peaks, in 1993, 2001, and 2007. However, age-adjusted incidence rates showed no significant increase over time. The national mortality rate was calculated to be 24.13 deaths per 100,000 males per year. A decrease was noted in crude and age-adjusted mortality rates between 1992 and 2010. Several provinces, cities, and FSAs had higher incidence/mortality rates than the national average. Several of the FSA postal codes with the highest incidence/mortality rates were adjacent to one another. Several Canadian regions of high incidence for prostate cancer have been identified through this study and temporal trends are consistent with those reported in the literature. These results will serve as a foundation for future studies that will seek to identify new regional risk factors and etiologic agents.

How Effective is Population-Based Cancer Screening? Regression Discontinuity Estimates from the US Guideline Screening Initiation Ages

We estimate the marginal benefits of population-based cancer screening by comparing cancer test and detection rates on either side of US guideline-recommended initiation ages (age 40 for breast cancer and age 50 for colorectal cancer during the study period). Using a regression discontinuity design and self-reported test data from national health surveys, we find test rates for breast and colorectal cancer increase at the guideline age thresholds by 109% and 78%, respectively. Data from cancer registries in twelve US states indicate that cancer detection rates increase at the same thresholds by 50% and 49%, respectively. We estimate significant effects of screening on earlier breast cancer detection (1.2 cases/1000 screened) at age 40 and colorectal cancer detection (1.1 cases/1000 individuals screened) at age 50. Forty-eight and 73% of the increases in breast and colorectal case detection occur among middle-stage cancers (localized and regional) with most of the remainder among early-stage (in-situ). Our analysis suggests that the cost of detecting an asymptomatic case of breast cancer at age 40 via population-based screening is $107,000–134,000 and that the cost of detecting an asymptomatic case of colorectal cancer at age 50 is $473,000–485,000.

Association of sociodemographic factors and prostate-specific antigen (PSA) testing

OBJECTIVES

There are conflicting recommendations regarding the use of prostate specific antigen (PSA) as a screening test. Integral to this debate is an understanding of who is currently being tested. The purpose of this study was to provide a detailed account of PSA testing practices in a major Canadian city (Calgary, Alberta) and to identify variables that may affect access to the PSA test.

DESIGN AND METHODS

PSA test counts were retrieved from Calgary Laboratory Services' Laboratory Information System from January 1, 2011 to December 31, 2011. A total of 75,914 individual PSA tests were included in our analysis. The frequency of PSA testing was plotted onto a dissemination area map of Calgary using ArcGIS software. Associations with sociodemographic variables were tested using Poisson regression.

RESULTS

The median PSA value was 0.93 μg/L and the median age at collection was 58 years. Forty-three percent of men aged 60-69 received a PSA test. Visible minority status 'Black' (P=0.0002) and Métis status (P=0.0075) were associated with lower PSA testing frequencies, while median household income (P=<0.0001) and university education (P=<0.0001) were associated with higher PSA testing frequencies.

CONCLUSION

There are areas in Calgary which are significantly over or under tested relative to the mean. The amount of PSA testing in men <50 years of age is increasing, which is contrary to PSA testing guidelines.

Explaining variations in breast cancer screening across European countries

OBJECTIVE

In this study I aim to explore the statistical causes of country differences in mammography screening among women aged 50-69 years in 13 European countries. I focus on the relative importance of individual (e.g. age, education, etc.) and institutional (e.g. public screening programmes) factors in explaining these differences.

DATA AND METHODS

I use individual level data from the first three waves (2004-2006-2009) of the SHARE as well as regional and country level data on institutional factors. The analytical approach is based on multilevel statistical models, which allow me to analyse the contribution of individual and institutional factors in explaining the variation in breast cancer screening across European countries.

RESULTS

I find that the standard deviation in screening rates across countries increases slightly from 19.5 to 20.8 per cent after controlling for individual factors. Observed individual factors such as age, education, health status, etc., do not significantly contribute to the explanation of cross-country differences. In contrast, after controlling for observed institutional factors such as the availability of an organised screening programme, the standard deviation drops from 20.86 to 12.92 per cent. These factors can statistically explain about 40 per cent of the between-country differences in screening rates. Moreover, I found that these institutional factors seem to prevent a woman from considering a mammogram "not necessary".

CONCLUSION

This analysis provides important insights about patient's attitudes and understanding of benefits of breast cancer prevention and highlights the importance of the availability of an organised screening programme for screening differences across European countries.

Efficacy of an educational intervention on family physicians' risk assessment and management of colorectal cancer

We developed a point-of-care tool indicating risk categories for colorectal cancer (CRC) based on family history (FH) and management recommendations tailored to risk. The study objective was to determine if this CRC Risk Triage/Management Too would enable family physicians (FPs) to appropriately triage and make screening and genetics referral recommendations for patients with CRC FH. Baseline questionnaires were mailed to a random sample of FPs in Ontario and Newfoundland, Canada. Participants were asked to use the tool for 3 months and then complete a follow-up questionnaire. The primary outcomes were correct responses to questions regarding CRC risk category, screening method, starting age, frequency, and decision to refer to genetics, for eight clinical vignettes. The study was completed by 75/121 (62 %) participating FPs. Most (77 %) agreed they routinely recommended fecal occult blood testing for average risk patients age ≥50. This did not change significantly following the intervention. There was a significant increase in confidence in CRC risk assessment (52 % pre; 88 % post; p < 0.001), correct management recommendations for patients with CRC FH (51 % pre; 84 % post; p < 0.001), and improvement in total mean scores on outcome measures for all vignettes. Most (90 %) agreed the tool would improve practice. Receipt of the CRC Risk Triage/Management Tool was associated with improvement in FPs' CRC risk assessment, screening, and genetics referral recommendations for clinical vignettes. This demonstrates the value of point-of-care tools and illustrates a process for development, evaluation, and dissemination of tools needed by FPs if potential impacts of genomic advances are to be achieved.