[Table/Fig-3]:

Guidelines to evaluate the quality of prevalence studies.

Sampling
(1)	Are the samples obtained through field survey?
(2)	Does the survey design yield a sample of respondents representative of a defined target population?
(3)	Is the target population defined clearly?
(4)	Do the characteristics of respondents match the target population?
Measurement
(5)	Do the survey instruments yield reliable and valid measures of disease?
(6)	Are the data collection methods standardised?
(7)	Are the survey index reliable?
(8)	Are the survey index valid?
Analysis
(9)	Were special features of the sampling design accounted for in the analysis?
(10)	Do the data include confidence intervals for statistical estimates?