Study selection and data extraction
Two reviewers independently performed the selection of study, which was
based on an initial screening of identified titles and abstracts and a
second screening of full-text articles. Studies were considered eligible
if they met the following criteria: (i) studies reporting anti-diabetic
medication non-adherence or adherence and or factors associated with
medication non-adherence; (ii) studies using observational study design
(cross-sectional); (iii) studies conducted in LMICs as defined by the
World Bank 9; (iv)
studies written in English after year of 2000 and (v) published studies
which were accessible with full text. We used the following exclusion
criteria: studies conducted in high-income countries, studies with no
information about adherence/non-adherence to anti-diabetic medications,
studies assessing adherence to diet, studies with languages other than
English, non-cross-sectional studies, and studies including other types
of therapy than allopathic medicine to manage diabetes. Studies with
incomplete information or no full text available were also excluded.
Two independent authors performed study screening and data extraction
judiciously according to inclusion criteria. Any discrepancies were
resolved through discussion of the third author until consent was
achieved. A standard data extraction format was used to collect the
study information, including name of the first author, year of the
publication, country, study design, population, interventions, study
settings, sample size, age (years), duration of diabetes (years),
adherence measures (self-reported or instruments), response rate (%),
proportion of non-adherence to anti-diabetic medication, and where
available, odds ratio (ORs) with respective confidence intervals (CIs)
for factors associated with adherence/non-adherence.