Table 2

The methodological assessment of selected studies

First author and year of publication
Blasco, 19968Camp-Bruno, 19896Lewis, 19947Mier, 20005Reddihough, 19909Stern, 199710Owen, 199211
0 = other sub-item satisfied, 1 = item not performed nor described, 2 = item incompletely performed or inappropriately described, 3 = item performed or adequately described.
Research designCohort studyRCTRCTRCTCohort studyCohort studyExperiment
Maximum possible sum score54606060545460
Internal validity Scores (minimally required score for specific item)
1RandomisationNA3 (2)2 (2)1 (2)NANA3 (2)
2aHomogeneity of the population2 (3)3 (2)0 (2)3 (2)3 (3)3 (3)2 (2)
2bSubgroup analysis0 (3)0 (2)2 (2)0 (3)0 (3)0 (3)0 (2)
3Adherence to therapy1 (3)3 (3)1 (3)1 (3)1 (3)3 (3)1 (3)
4Co-intervention control system1311111
5Standardised outcome measure1 (2)2 (2)2 (2)2 (2)3 (2)2 (2)2 (2)
6Repeated measurements1333213
7Intention to treatNA1 (3)1 (3)1NANA0 (3)
External validity
8Inclusion/exclusion criteria3 (3)3 (3)3 (3)13 (3)1 (3)1 (3)
9Description of intervention3 (3)3 (3)3 (3)3 (3)3 (3)3 (3)3 (3)
10Co-intervention checked3111131
11Outcome rates listed in text1 (3)3 (3)3 (3)3 (3)3 (3)1 (3)3 (3)
12Description and management of “lost to follow up”3 (3)3 (3)3 (3)3 (3)1 (3)3 (3)1 (3)
13Number of “lost to follow up”3 (3)3 (3)3 (3)3 (3)1 (3)3 (3)1 (3)
14Follow up period3113323
15Side effects3323333
Data presentation
1Adequate sample size3 (3)3 (3)3 (3)3 (3)3 (3)3 (3)1 (3)
2Mean1 (3)3 (3)1 (3)3 (3)3 (3)1 (3)1 (3)
3Standard deviation1 (3)3 (3)1 (3)3 (3)3 (3)1 (3)1 (3)
4Statistical method1313333
5Statistical analysis performed1333333