2.3. Sample Size and Sampling Procedures

A total of 320 mothers of children aged 0-6 months were included in the study. The sample size was determined based on a single population proportion formula (Z²P(1 − P)/(e)²) with a 95% Cl, 5% margin error (Zα/2 = 1.96) by considering the national adherence to IFAS (P = 21%) [4] at 80% desired power (Bα) and 10% of the estimated nonresponse rate. Nonresponse was considered to maximize the sample size of 320 study respondents.

Mothers of children aged 0-6 months were systematically sampled from a list of clients attending postnatal services in the two facilities. These included Kasulu Hospital and Kiganamo Health Center which are well known to accommodate and provide maternal services to a large number of pregnant women compared to other health facilities in Kasulu town. This study was done between March and April 2019. In addition, 40 respondents were purposively selected and involved in a qualitative study. These included six health care providers who participated in in-depth interviews (IDIs), 19 pregnant women, and 15 mothers with children aged 0-6 months who participated in focus group discussions (FGDs). A total of four FGDs were conducted of which two comprised of pregnant women and two comprised of mothers of children aged 0-6 months. Each FDG included 7-11 respondents.