Community-based settings and sampling strategies: implications for reducing racial health disparities among black...

Rates of screening colonoscopies, an effective method of preventing colorectal cancer, have increased in New York City over the past decade, and racial disparities in screening have declined. However, vulnerable subsets of the population may not be reached by traditional surveillance and intervention efforts to improve colorectal cancer screening rates.

We compared rates of screening colonoscopies among black men aged 50 or older from a citywide random-digit-dial sample and a location-based sample focused on hard-to-reach populations to evaluate the representativeness of the random-digit-dial sample. The location-based sample (N = 5,568) was recruited from 2010 through 2013 from community-based organizations in New York City. Descriptive statistics were used to compare these data with data for all black men aged 50 or older from the 2011 cohort of the Community Health Survey (weighted, N = 334) and to compare rates by community-based setting.

Significant differences in screening colonoscopy history were observed between the location-based and random-digit-dial samples (49.1% vs 62.8%, P < .001). We observed significant differences between participants with and without a working telephone among the location-based sample and between community-based settings.

Vulnerable subsets of the population such as those with inconsistent telephone access are excluded from random-digit-dial samples. Practitioners and researchers should consider the target population of proposed interventions to address disparities, and whether the type of setting reaches those most in need of services.