Date Published: July 6, 2015
Publisher: Public Library of Science
Author(s): Stacey A. Fedewa, Stéphane Cullati, Christine Bouchardy, Ida Welle, Claudine Burton-Jeangros, Orly Manor, Delphine S. Courvoisier, Idris Guessous, Keping Xie.
Despite universal health care coverage, disparities in colorectal cancer (CRC) screening by income in Switzerland have been reported. However, it is not known if these disparities have changed over time. This study examines the association between socioeconomic position and CRC screening in Switzerland between 2007 and 2012.
Data from the 2007 (n = 5,946) and 2012 (n = 7,224) population-based Swiss Health Interview Survey data (SHIS) were used to evaluate the association between monthly household income, education, and employment with CRC screening, defined as endoscopy in the past 10 years or fecal occult blood test (FOBT) in the past 2 years. Multivariable Poisson regression was used to estimate prevalence ratios (PR) and 95% Confidence Intervals (CI) adjusting for demographics, health status, and health utilization.
CRC screening increased from 18.9% in 2007 to 22.2% in 2012 (padjusted: = 0.036). During the corresponding time period, endoscopy increased (8.2% vs. 15.0%, padjusted:<0.001) and FOBT decreased (13.0% vs. 9.8%, padjusted:0.002). CRC screening prevalence was greater in the highest income (>$6,000) vs. lowest income (≤$2,000) group in 2007 (24.5% vs. 10.5%, PR:1.37, 95%CI: 0.96-1.96) and in 2012 (28.6% vs. 16.0%, PR:1.45, 95%CI: 1.09-1.92); this disparity did not significantly change over time.
While CRC screening prevalence in Switzerland increased from 2007 to 2012, CRC screening coverage remains low and disparities in CRC screening by income persisted over time. These findings highlight the need for increased access to CRC screening as well as enhanced awareness of the benefits of CRC screening in the Swiss population, particularly among low-income residents.
In 2012, 1,361,000 people were diagnosed with colorectal cancer (CRC) and 694,000 people died from CRC worldwide.  The majority of CRCs are diagnosed in developed countries. For example, world-age-standardized CRC incidence in New Zealand, Australia, Canada, United States and Western Europe, including Switzerland, exceeds 25 cases per 100,000 people.  In order to reduce CRC incidence and mortality, fecal occult blood testing (FOBT) annually, sigmoidoscopy every 5 years with hemoccult periodically or colonoscopy every 10 years are recommended for average-risk adults between 50–75 years by European Panel  and the US Preventive Services Task Force.  There is no national organized CRC screening program in Switzerland and CRC screening among Swiss residents is low. According to the 2007 Swiss Health Interview Survey (SHIS), only 13% of adults ≥ 50 years had a hemoccult test or endoscopy in the past 5 years for screening reason.  In addition to suboptimal CRC screening utilization in Switzerland, social inequalities have been noted where adults highest income bracket were 70% more likely to receive a screening endoscopy. However, temporal patterns of CRC screening patterns by socioeconomic status have not been investigated, which is of interest given a recent Swiss study reporting growing disparities in healthcare renunciation between 2007 and 2010  and projected increases in CRC incidence. The last population based SHIS in 2012 provides an opportunity to examine temporal patterns of CRC screening by socioeconomic status, measured by household income, education, and employment status. This study examines the association between socioeconomic position and CRC screening prevalence as well as potential changes of social disparities between 2007 and 2012 in the SHIS.
5,946 and 7,224 respondents from the 2007 and 2012 SHIS were analyzed, respectively. Respondent socioeconomic characteristics varied between the two surveys. (Table 1) The median household income increased from $4,000 in 2007 to $4,130 in 2012. During the study period, there was a 5.2% decrease in respondents with secondary education and 7.2% increase in respondents reporting part or full-time employment. The proportion of divorced or separated respondents increased between 2007 and 2012. In terms of health indicators, obesity and psychological distress prevalence increased slightly between 2007 and 2012, while physical symptoms decreased during the period. Health services use also varied with time. The proportion of respondents reporting visiting a general practitioner within the past year declined from 81.5% in 2007 to 72.4% in 2012 whereas specialist visits increased slightly from 39.8% in 2007 to 43.0% in 2012 (Table 1).
This study is the first to examine nationwide CRC screening trends in Switzerland. While CRC screening prevalence increased between 2007 and 2012, CRC screening utilization remains low, especially among adults with low income. The growth in CRC screening prevalence was due to greater use of endoscopy, which is in line with screening patterns in the United States. [15, 16] Yet, CRC screening prevalence in Switzerland (22%) is lower than the US where 58% of eligible adults are up to date with CRC screening.  Additionally, CRC screening prevalence in Switzerland, which does not have an organized CRC screening program, is considerably lower than in other European countries with organized screening programs [18–20] but similar to European countries (e.g: Belgium, Netherlands and Denmark) without organized screening programs.  Our CRC screening prevalence estimates were similar to other previous population-based estimates, but lower than surveys among hospital series, which is likely due to differences in study populations and we excluded diagnostic hemoccult and endoscopies. [10, 21]
This study is the first to examine nationwide changes CRC screening in Switzerland. While CRC screening prevalence in Switzerland increased from 2007 to 2012, CRC screening utilization remains insufficient. Additionally, low income Swiss residents had particularly inadequate CRC screening prevalence and this disparity persisted over time. These findings highlight the need for tailored interventions to increase the access to CRC screening, as well as increasing awareness of the benefits of CRC screening in the Swiss population, particularly among low-income residents. Additionally, the impact of adding CRC screening as a covered benefit to the basic Swiss health insurance plans in 2013 needs to be determined.