Protocol Design for Large-Scale Cross-Sectional Studies of Surveillance of Risk Factors of Non-Communicable Diseases in Iran: STEPs 2016.

INTRODUCTION: The rise in non-communicable diseases (NCDs) has gained increasing attention. There is a great need for reliable data to address such problems. Here, we describe the development of a comprehensive set of executive and scientific protocols and instructions of STEPs 2016.

METHODS/DESIGN: This is a large-scale cross-sectional study of Surveillance of Risk Factors of NCDs in Iran. Through systematic proportional to size cluster random sampling, 31,050 participants enrolled in three sequential processes, of completing questionnaires; physical measurements, and lab assessment.

RESULTS: Out of 429 districts, samples were taken from urban and rural areas of 389 districts. After applying sampling weight to the samples, comparing the distribution of population and samples, compared classification was determined in accordance with the age and sex groups. Out of 31,050 expected participants, 30,541 participant completed questionnaires (52.31% female). For physical measurements and lab assessment, the cases included 30,042 (52.38% female) and 19,778 (54.04% female), respectively.

DISCUSSION: There is an urgent need to focus on reviewing trend analyses of NCDs.To the best of our knowledge, the present study is the first comprehensive experience on systematic electronic national survey. The results could be also used for future complementary studies.