Table 1.

Criteria used to assess the methodological quality of selected cohort and cross-sectional studies

Item	Criterion	Study type
Study population
1	Selection before disease was present or at uniform point	CH/CC/CS
2	Cases and controls were drawn from the same population	CC
3	Participation rate ≥80% for cases/cohort	CH/CC/CS
4	Participation rate ≥80% for controls	CC
5	Sufficient description of baseline characteristics	CH/CC/CS
Assessment of risk factor
6	Psychosocial assessment was blinded	CH/CC/CS
7	Psychosocial factors were measured identical for cases and controls	CC
8	Psychosocial factors were assessed prior to the outcome	CH/CC/CS
Assessment of outcome
9	Knee OA/pain was assessed identical in studied population	CH/CC/CS
10	Presence of knee OA/pain was assessed reproducibly	CH/CC/CS
11	Presence of knee OA/pain was assessed according to standard definitions	CH/CC/CS
Study design
12	Prospective design was used	CH/CC/CS
13	Follow up time ≥2 years	CH
14	Withdrawals ≤20%	CH
Analysis and data presentation
15	Appropriate analysis techniques were used	CH/CC/CS
16	Adjusted for at least age and sex	CH/CC/CS

CH, Applicable to cohort studies; CC, Applicable to case-control studies; CS, Applicable to cross-sectional studies; OA, Osteoarthritis.