What's all that noise?The effect of co-morbidity on health outcome questionnaire results after knee arthroplasty

Abstract

Background We modified the Charnley Classification for hips to facilitate its use with knee arthroplasty patients and investigated what affect the different classes of co-morbidity had on the results of a spectrum of outcome questionnaires.Patients and methods 3600 patients from the Swedish Knee Arthroplasty Registry were surveyed by post with a variety of questionnaires ranging from multipleitem general health, to a single-item knee arthroplasty specific questionnaire. All patients also completed a co-morbidity questionnaire, from which a modified Charnley Classification was generated for each patient. We then investigated the correlation and relationship between the results of the questionnaires and the different classes of co-morbidity.Results The results of the questionnaires tested varied significantly by Charnley Class, regardless of the specificity of the questionnaire used.Interpretation We suggest that co-morbidity should be taken into account in outcome studies utilizing general health or disease/site specific questionnaires.

Standard Comorbidity Measures Do Not Predict Patient-reported Outcomes 1 Year After Total Hip Arthroplasty

“…Despite the simplicity of the original Charnley classification [5], surgeon-assigned classification has a high [7,21]. It was recently shown that the classification does not require splitting because patients naturally classify themselves similarly to Charnley classification definitions [10].…”

The influence of comorbidity on the risks and benefits of spine surgery for degenerative lumbar disorders

“…Many studies have focused on the complications associated with increasing comorbidity, but few have evaluated the corresponding patient-centred treatment outcomes. Whilst some studies in the field of orthopaedics have shown that comorbidity impacts on the absolute scores of function or quality of life recorded preoperatively [4] or at follow-up [5], only few studies have addressed its influence on changes in health-related outcomes after surgery, and these have produced conflicting results. In patients undergoing total hip replacement, Imamura et al [6] showed that there is no influence of comorbidity on the change in health status as measured by functional, recreational, and social activities of daily living.…”

Comorbidity‐related quality of life in anterior cruciate ligament insufficiency: A cross‐sectional study involving 282 candidates for arthroscopic reconstruction

“…SF-36 profiles should, however, be controlled for medical comorbidities because comorbid illness would cause what has been referred to as a "background noise", blurring the potential association between HRQoL and musculoskeletal disorders (Dunbar et al 2004).…”