Yoeri Bemelmans

Chapter 10 156 Table 1. Differences between both pathways extracted for pre-, peri- and postoperative care and discharge criteria. Enhanced Recovery Pathway Outpatient Surgery Pathway Preoperative Admission Night before/day of operation Day of operation Planned discharge <3 days postoperative Day of admission Perioperative Antibiotics prophylactic I.v. I.v. and oral Postoperative First mobilization <6hrs <4hrs Compression bandages 24hrs postoperative 8hrs postoperative, first 4 days postoperative elastic bandage Prior to each outpatient visit (preoperative, 3- and 12-months postoperative) patients filled out 4 different Patient reported outcomemeasures (PROMs) as standard control in our department for knee arthroplasty patients. PROMs included the EuroQol-5D (EQ-5D; 0 to 1, 1 indicates the best health state) [15], Oxford Knee Score (OKS; 12 to 60, 12 being the best outcome) [16] and theWestern Ontario andMcMaster Universities Arthritis Index (WOMAC; 0 to 100, 100 being the best outcome) [17]. Experienced painwas measured by a Numerical Rating Scale (NRS, 0 to 10, 10 being ‘worst pain’). This study was validated and approved by the Independent Review Board (METC Z, Heerlen, the Netherlands; IRB-nr.16N194) and registered online at the Dutch Trial Register (www.trialregister.nl ). Statistical analysis SPSSVersion 17.0 forwindows (Inc., Chicago, IL)was used. Standarddescriptive statistics wereused todescribe thepatient demographic data andbaseline characteristics. Fisher’s exact test was used to test differences of proportions. Students T-tests were performed on the baseline conditions for significant interactions. Amixedmodel (GLMM) approach was used to take into account the repeated-measures design of the study, to cope with anymissing data being collected during the pre-, 3- and 12-months postoperative follow- up and to cope with the wide range of a possible variation in relation to the time-frame the data was collected [18]. The GLMM contained fixed variables, to estimate the effect of the different pathways and age on the trend of the PROMs (dependent variables). For all analyses, a p-value was considered to be statistically significant at P ≤ 0.05.