Table 2

Risk of bias in included studies. With the Quality in Prognostic Studies tool studies were assessed on the overall risk of bias within each of the six domains and rated as low, moderate or high risk of bias

Study author yearDesignStudy participationStudy attritionPrognostic factor measurementOutcome measurementStudy confoundingStatistical analysis and presentation
Blauuw et al 201519Prospective cohortLowModerateLowLowModerateLow
Brattberg 199320Prospective cohortModerateModerateLowLowModerateHigh
Brattberg 200421Prospective cohortLowModerateLowLowLowLow
El-Metwally et al 200422Prospective cohortLowLowLowLowLowLow
El-Metwally et al 200549Prospective cohortLowLowLowLowLowLow
Flatø et al 199723Prospective cohortLowLowLowLowLowLow
Holley et al 201724Prospective cohortLowLowLowLowLowLow
Jones and Macfarlane 200925Prospective cohortLowModerateLowLowLowLow
Jussila et al 201426Prospective cohortLowModerateLowLowLowLow
Laimi et al 200727Prospective cohortLowModerateLowLowLowLow
Lunde et al 201528Prospective cohortLowModerateLowLowLowLow
Mikkelsson et al 199729Prospective cohortLowLowLowLowModerateModerate
Mikkelsson et al 199830Prospective cohortLowLowLowLowLowModerate
Mikkelsson et al 199931Prospective cohortLowLowLowLowLowLow
Mikkonen et al 200832Prospective cohortLowModerateLowLowLowLow
Mikkonen et al 201233Prospective cohortModerateLowLowLowLowLow
Mikkonen et al 201334Prospective cohortLowModerateLowLowLowLow
Paananen et al 201035Prospective cohortLowModerateLowLowLowLow
Rathleff et al 20139Prospective cohort and nested case–controlModerateLowLowLowLowLow
Rathleff et al 201636*Prospective cohortLowLowLowLowLowLow
Rathleff et al 201637Prospective cohortLowLowLowLowLowLow
Sjölie and Ljunggren  200138Prospective cohort study with a cross sectional partLowLowLowLowLowLow
Sperotto et al 201539Prospective cohortLowModerateLowLowHighModerate
Stanford et al 200817Prospective cohortLowModerateLowLowLowLow
Ståhl et al 200840Prospective cohortLowModerateLowLowModerateLow
Uziel et al 201041Prospective cohortModerateLowLowLowHighModerate
  • *‘Is knee pain during adolescence a self-limiting condition?’