A Nationwide Evaluation of the Prevalence of Human Papillomavirus in Brazil (POP-Brazil Study): Protocol for Data Quality Assurance and Control (Preprint)

Abstract

BACKGROUND The credibility of a study and its internal and external validity depend crucially on the quality of the data produced. Quality control aims to monitor sampling errors and measurements during the execution of a study and is based mainly on two pillars: planning and standardization of procedures. OBJECTIVE The present article aimed to describe the stages of quality control in the POP-Brazil study and to present an analysis of the quality indicators. METHODS Quality assurance and control included several phases and processes that were initiated with the planning of the study and continued through the development of the project; thus, all centers were trained in loco. RESULTS The data were through a structured questionnaire and collection of biological samples, both performed by more than 250 trained and certified health professionals. Furthermore, to correct possible inadequacies, all 119 centers (public health units) received at least one monitoring visit, which evaluated the professionals' performance and the process of completing the online data platform. The data were monitored daily and were audited through the double entry of data, performed by the central team. The reliability of data was analyzed through the test-retest method, comparing data from the online platform and a second application of the interview, and conducted through telephone, also by the central team. The agreement between the test and retest was considered good (kappa between 0.59 and 0.74). Large multicenter clinical trials are the basis of medical evidence-based and health-based prevention, so their design, logistics, and quality processes should always be carefully considered. CONCLUSIONS This article presents the processes and quality indicators in the POP-Brazil study that allow other studies to generate reliable data.