Fig. 2From: Validation of an electronic coding algorithm to identify the primary indication of orthopedic surgeries from administrative dataNegative Predictive Values of Algorithm for the Procedure/Primary Indication Combinations of Interest. The prior probabilities in the study sample were 0.31 for spinal surgery/spinal stenosis, 0.13 for spinal surgery/herniated disc, 0.27 for knee arthroplasty/knee osteoarthritis, and 0.30 for hip arthroplasty/hip osteoarthritis. Marks indicating the NPV for these prior probabilities are included in the figureBack to article page