Table 2.
Results of quality appraisal of included studies
| Study | Were 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 | N | N | N | N | N | Y | Y | 2/7 |
| Stewart et al 33 | N | N | Y | Y | N | Y | Y | 4/7 |
| Jagsi et al 39 | Y | N | Y | N | N | Y | Y | 4/7 |
| Seritan et al 42 | N | Y | N | N | N | N | Y | 2/7 |
| Von Feldt 47 | N | N | Y | N | N | N | Y | 2/7 |
| Bauman et al 46 | N | N | N | N | N | Y | Y | 2/7 |
| Helitzer et al 41 | N | Y | Unclear | N | N | Y | Y | 3/7 |
| Valantine et al 43 | N | N | N | N | N | Y | Y | 2/7 |
| Study | Is it clear in the study what is the ‘cause’ and what is the ‘effect’ (ie, there is no confusion about which variable comes first)? | Were the participants included in any comparisons similar? | Were the participants included in any comparisons receiving similar treatment/care other than the exposure or intervention of interest? | Was there a control group? | Were there multiple measurements of the outcome both before and after the intervention/exposure? | Was follow-up complete and if not, were differences between groups in terms of their follow-up adequately described and analysed? | Were the outcomes of participants included in any comparisons measured in the same way? | Were outcomes measured in a reliable way?† | Was appropriate statistical analysis used?‡ | Score |
| Quasi-experimental checklist (pre-test and post-test or controlled studies) | ||||||||||
| McDade et al 37 | Y | Y | Y | N | N | N | Y | N | Y | 5/9 |
| Gardiner et al 30 | Y | Unclear | Unclear | Y | N | N | Y | Y | Unclear | 4/9 |
| Dannels et al 36 | Y | N | Y | Y | N | N | Y | Y | Y | 6/9 |
| Files et al 34 | Y | Y | Y | N | N | Y | Y | N | Y | 6/9 |
| Dutta et al 31 | Y | Y | Y | N | N | N | Y | Y | Y | 6/9 |
| Carnes et al 45 | Y | Y | Y | N | N | N | Y | N | N | 4/9 |
| Varkey et al 40 | Y | Y | Y | N | N | N | Y | N | Y | 5/9 |
| Levine et al 32 | Y | Y | Y | N | N | Y | Y | N | Y | 6/9 |
| Chang et al 35 | N | N | Y | Y | Unclear | Y | Y | Y | Y | 6/9 |
| Girod et al 44 | Y | Y | Y | N | N | Y | Y | Unclear | Y | 6/9 |
*The ‘exposure’ was considered intervention attendance/adherence.
†Validated tool used (with figures provided) or reliable figures like rank.
‡Studies employing descriptive analysis only were considered appropriate.