Quantitative Methods 2017

• Prognostic factor: – Factor that is associated with outcome • Predictive factor: – Factor that predicts whether certain treatment approach is beneficial • Obtained from RCT’s (hypothesis generating: power!) • Preferably obtained from meta-analysis – Factor that predicts whether certain prognostic factor is associated with endpoint • May negatively affect power and required number of patients in prognostic factor studies Prognostic vs. predictive factor