Recruiting population controls for case-control studies in sub-Saharan Africa: The Ghana Breast Health Study

Abstract

Background In case-control studies, population controls can help ensure generalizability; however, the selection of population controls can be challenging in environments that lack population registries. We developed a population enumeration and sampling strategy to facilitate use of population controls in a breast cancer case-control study conducted in Ghana. Methods Household enumeration was conducted in 110 census-defined geographic areas within Ghana’s Ashanti, Central, Eastern, and Greater Accra Regions. A pool of potential controls (women aged 18 to 74 years, never diagnosed with breast cancer) was selected from the enumeration using systematic random sampling and frequency-matched to the anticipated distributions of age and residence among cases. Multiple attempts were made to contact potential controls to assess eligibility and arrange for study participation. To increase participation, we implemented a refusal conversion protocol in which initial non-participants were re-approached after several months. Results 2,528 women were sampled from the enumeration listing, 2,261 (89%) were successfully contacted, and 2,106 were enrolled (overall recruitment of 83%). 170 women were enrolled through refusal conversion. Compared with women enrolled after being first approached, refusal conversion enrollees were younger and less likely to complete the study interview in the study hospital (13% vs. 23%). The most common reasons for non-participation were lack of interest and lack of time. Conclusions Using household enumeration and repeated contacts, we were able to recruit population controls with a high participation rate. Our approach may provide a blue-print for others undertaking epidemiologic studies in populations that lack accessible population registries.

Breast self-examination practice and associated factors among female healthcare workers in Ethiopia: A systematic review and meta-analysis

“…Thus, early detection based on awareness of early signs and symptoms should prioritize [ 8 ]. In Africa, breast cancer prevention and control is comparatively limited [ 5 , 23 ]. In addition, registries which play a critical role in cancer surveillance are limited with only 43.4% countries have active cancer registries in SSA [ 24 ].…”

Reproductive factors and risk of breast cancer by tumor subtypes among Ghanaian women: A population‐based case–control study

“…(12,13) A population-based case-control study of breast cancer in Ghana aimed to overcome challenges of previous African studies that were unable to select population-based controls and properly classify hormone receptor-negative cases. (3,12,14,15) Using a census-based sampling of controls (16) and standardized protocols for collecting tumor biopsy samples for immunohistochemical (IHC) staining from cases prior to treatment (17), we sought to determine the associations between menstrual and reproductive risk factors and breast cancer subtypes.…”

Reproductive Factors and Risk of Breast Cancer by Tumor Subtypes among Ghanaian Women: A Population-based Case-control Study

“…(12,13) A population-based case-control study of breast cancer in Ghana aimed to overcome challenges of previous African studies that were unable to select population-based controls and properly classify hormone receptor-negative cases. (3,12,14,15) Using a census-based sampling of controls (16) and standardized protocols for collecting tumor biopsy samples for immunohistochemical (IHC) staining from cases prior to treatment (17), we sought to determine the associations between menstrual and reproductive risk factors and breast cancer subtypes.…”