Table 1 KneeOA: assessment of the study quality
AuthorsDesign and materialsAdjusted for confoundersMeasurement of outcomeMeasurement of exposureData presentation and statistical analysisQuality assessment score*Total score
Kellgren and Lawrence, 19529212027++
Wickström et al, 198310232029++
Greinemann, 198811112015+
Anderson and Felson, 1988123212311+++
Enderlein and Karsch, 19895222028++
Kohatsu and Schurmann, 199013112004+
Vingaard et al, 199114221128++
Bagge et al, 199115212128++
Felson et al, 1991162232211+++
Vingaard et al, 199217211026++
Schouten et al, 199218112228++
Kivimäki et al, 199219232029++
Cooper et al, 199420123129++
Jensen et al, 199421211026++
Elsner et al, 199622211126++
Sahlström and Montgomery, 199723301026++
Jensen et al, 200024232018++
Coggon et al, 2000252233313+++
Lau et al, 2000263222211+++
Sandmark et al, 2000273233314+++
Seidler et al, 2001282203310++
Dawson et al, 200229123028++
Manninen et al, 200230†3233314+++
Yoshimura et al, 200431222028++
Holmberg et al, 2004323113210++
  • Each item was scored from 1–3. The quality of the study was assessed by the sum of the scores, the maximum being 15 points.

  • Several of the studies included more than one exposure, and have been cited more than once.

  • *The papers were subdivided into: poor quality (score 1–5); medium quality (score 6–10); high quality (score 11–15).

  • †The only high-quality study that included women.