Table 1.
Methodological appraisal of studies
| Comparable cohort/case control studies | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| First author (Year) | Q1 | Q2 | Q3 | Q4 | Q5 | Q6 | Q7 | Q8 | Q9 |
| Kenealy et al. (2010) [26] | Y | N | Y | Y | Y | Y | N | Y | U |
| Smith et al. (2011) [27] | Y | Y | Y | Y | Y | Y | N/A | Y | Y |
| Schraer et al. (2003) [25] | Y | U | Y | Ya | Y | Y | Y | Y | Y |
| Ralph-Campbell et al. (2006) [31] | N | N | Y | Y | Y | N | Y | Y | Y |
| % | 75 | 25 | 100 | 100 | 100 | 75 | 50 | 100 | 75 |
| Observational studies | |||||||||
| First author (Year) | Q1 | Q2 | Q3 | Q4 | Q5 | Q6 | Q7 | Q8 | Q9 |
| Bailie et al. (2004) [20] | Y | Y | Ya | Y | Y | Y | N | N | Y |
| Bailie et al. (2007) [21] | N | Y | Y | Y | Y | Y | N | N | Y |
| Roubideaux et al. (2008) [23] | N | Y | Y | Y | Y | U | N | Y | Y |
| Wilson et al. (2005) [22] | Y | Y | Y | Y | Y | Y | N | Y | Y |
| Simmons et al. (2003) [28] | N | Y | N | U | Y | Y | Y | N | Y |
| Ramesh et al. (2008) [24] | Y | Y | Y | Y | Y | Y | N/A | Y | Y |
| Virani et al. (2006) [32] | N | Y | N | Y | Y | N | N | N | Y |
| % | 42.86 | 100 | 71.43 | 85.71 | 100 | 71.43 | 14.29 | 42.86 | 100 |
| Randomised control trial /Pseudo-randomised trial | |||||||||
| First author (Year) | Q1 | Q2 | Q3 | Q4 | Q5 | Q6 | Q7 | Q8 | Q9 |
| McDermott et al. (2001) [29] | U | N | N | N | U | Y | Y | Y | Y |
| Tobe et al. (2006) [30] | Y | N | N | Y | N | Y | Y | Y | Y |
| % | 50 | 0 | 0 | 50 | 0 | 100 | 100 | 100 | 100 |
Note: Y – Yes, N – No, U- Unclear, N/A – Not applicable.
aPotential confounding factors were identified in qualitative research and not captured in statistical models.
Comparable cohort criteria: 1) Is the sample representative of patients in the cohort as a whole? 2) Are the patients at a similar point in the course of their condition/illness? 3) Has bias been minimised in relation to selection of cases and of controls? 4) Were confounding factors identified and strategies to deal with them stated? 5) Were outcomes assessed using objective criteria? 6) Was follow-up carried out over a sufficient time period? 7) Were the outcomes of people who withdrew described and included in the analysis? 8) Were outcomes measured in a reliable way? 9) Was appropriate statistical analysis used?
Observational criteria: 1) was the study based on a random or pseudo-random sample? 2) Were the criteria for inclusion in the sample clearly defined? 3) Were confounding factors identified and strategies to deal with them stated? 4) Were outcomes assessed using objective criteria? 5) If comparisons are being made, was there sufficient description of the groups? 6) Was follow up carried out over a sufficient time period? 7) Were the outcomes of people who withdrew described and included in the analysis? 8) Were outcomes measured in a reliable way? 9) Was appropriate statistical analysis used?
Randomised control trial criteria: 1) Was the assignment to treatment groups truly random? 2) Were participants blinded to treatment allocation? 3) Was allocation to treatment groups concealed from the allocator 4) Were the outcomes of people who withdrew described and included in the analysis 5) Were those assessing outcomes blind to the treatment allocation 6) were the control and treatment groups comparable at entry? 7) Were groups treated identically other than for the named interventions? 8) Were outcomes measured in the same way for all groups? 9) Were outcomes measured in a reliable way? 10) Was appropriate statistical analyses used?.