Table 2

Results of quality appraisal of included studies

StudyWere the criteria for inclusion in the sample clearly defined?Were the study subjects and the setting described in detail?Was the exposure measured in a valid and reliable way?*Were confounding factors identified?Were strategies to deal with confounding factors stated?Were the outcomes measured in a valid and reliable way?†Was appropriate statistical analysis used?‡Score
Modified analytical cross-sectional checklist (observational and post-test only studies)
Richman et al 38 NNNNNYY2/7
Stewart et al 33 NNYYNYY4/7
Jagsi et al 39 YNYNNYY4/7
Seritan et al 42 NYNNNNY2/7
Von Feldt 47 NNYNNNY2/7
Bauman et al 46 NNNNNYY2/7
Helitzer et al 41 NYUnclearNNYY3/7
Valantine et al 43 NNNNNYY2/7