Joost Peerbooms

113 PRP in plantar fasciitis in the PRP group also showed significantly lower FFI Disability scores than patients in the control group (mean difference, 12.0; 95% CI, 2.3-21.6). For all WHOQOL-BREF outcomes the differences between the treatment groups at the 12-month follow-up failed to reach significance. Table 3 Difference Between Treatment Groups at the 12-Month Follow-up for all Outcome Measures α Outcome measure Treatment Effect F -test P value Partial Eta Squared Mean difference (95% CI) b FFI Pain c F (1,76) = 6.602 0.012 d 0.080 14.40 (3.24, 25.57) FFI Disability F (1,76) = 6.064 0.016 d 0.074 11.97 (2.29, 21.64) FFI Activity F (1,76) = 3.288 0.074 0.041 5.93 (-0.58, 12.44) AOFAS F (1,75) = 5.674 0.020 0.070 -11.27 (-20.69, -1.84) WHOQOL-BREF Overall QOL and General Health F (1,76) = 0 .001 0.975 0.000 -0.01 (-0.54, 0.52) Physical Health F (1,76) = 3.187 0.078 0.040 -1.18 (-2.50, 0.14) Psychological Health F (1,76) = 0.471 0.494 0.006 -0.25 (-0.96, 0.47) Social Relationships F (1,70) = 0.071 0.790 0.001 -0.15 (-1.24, 0.95) Environment F (1,76) = 0.029 0.866 0.000 0.08 (-0.82, 0.97) α Adjusted for between-group differences in baseline scores. AOFAS, American Orthopaedic Foot & Ankle Society; FFI, Foot Function Index; WHOQOL-BREF, World Health Organization Quality of Life. b A positive mean difference indicates a higher mean score in the control group than in platelet- rich plasma at 12-month follow-up. c Primary outcome measure. d Statistically significant after the Bonferroni correction (see the Statistical Analysis section). Last, Table 4 shows for both treatment groups the number of patients with at least 25% improvement in their FFI Pain score between baseline and the 12-month follow- up. It turns out that of the 46 patients in the PRP group, 39 (84.4%) improved at least 25%, while only 20 (55.6%) of the 36 patients in the control group showed such an improvement. This difference was statistically significant ( χ 2 [1], 8.6; P = .003; odds ratio, 4.5; 95% CI, 1.6-12.7). 7