Quality assessment of study design (rigor score*).

*One point score for meeting each of the following items (if data were not available in the articles for any item, 0.5 was recorded):(a)was a prospective cohort,(b)used a comparison arm,(c)collected pre and post intervention data,(d)used random assignment of participants to study arms,(e)did random sampling for assessments,(f)sample size >100,(g)follow-up rate ≥80%,(h)had a comparison group with comparable socio-demographics such as age, education, race, employment, income, marital status and others [score “1” if >50% variables were comparable between study arms, and ‘0’ if not], and(i)had a comparison arm with comparable outcome measures at baseline between study arms.