Page 30 - The value of total hip and knee arthroplasties for patients

Chapter 2
Questionnaire to Assess Health-enhancing physical activity (SQUASH) 20;21 or by the Dutch Norm of Healthy Exercise and Fitstandard; (d) expectations and satisfaction measured with the NewYork Hospital for Special Surgery Questionnaire22; (e) frailty assessed by means of the Groningen Frailty Index (GFI)23 and (f) knee-instability assessed by a self-reported knee joint instability questionnaire according to the questionnaire of Felson et al24 (g) status of living (living alone or with other people) and (h)smoking status (smoker/ non-smoker/ ex-smoker), .
Statistics
The feasibility of collecting multiple patient-reported outcome measures in the LOAS study alongside the Dutch Arthroplasty Register was determined by calculating the proportion of invited patients in the LOAS study that were included, the proportions of patients lost-to-follow-up, completion rates of questionnaires among eligible patients after 6, 12 and 24 months and overall response rates (patients initially included/patients returning a questionnaire) . Descriptive statistics were used for the preoperative baseline characteristics of included patients, with normally distributed data presented as mean and SD, data with a skewed distribution as median with ranges and categorical data as numbers with proportions.The age and sex distribution of patients included and not-included preoperatively were compared by means of unpaired t-test and Chi-Square tests, respectively.
RESULTS
Participation of hospitals and patient enrollment
From June 2012, the orthopaedic departments of 7 hospitals were invited to participate in the LOAS-study. The seven participating hospitals comprised one academic centre, one large teaching hospital and five general hospitals. The recruitment and inclusion of patients started in June 2012, within the subsequent 12 months all hospitals started the recruitment of patients.
Participation rates
Figure 1 describes the flow of patients. Of the 3631 identified and eligible patients who were admitted for THA/TKA surgery from June 2012 to December 2014, 1796/1893THA (95%) and 1636/1738TKA (94%) patients agreed to be contacted and were sent a set of PROMs. Of the 3432 invited patients, 1035/1796 THA (58%)
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