title: Can condition-specific health surveys be specific to spine disease? An analysis of the effect of comorbidities on baseline condition-specific and general health survey scores.
abstract: METHODS
  This is an observational cross-sectional study of 26,290 patients seen and evaluated in the 25 centers of the National Spine Network.
  
  
  OBJECTIVE
  To explore the correlation between medical and psychosocial comorbidities, and baseline Short-Form 36 Health Status questionnaire (SF-36) and Oswestry Disability Index (ODI) (Musculoskeletal Outcomes Data Evaluation and Management Systems version with scales reversed so that a score of 100 represents no disability, and a score of 0 represents severe disability) scores in spine patients.
  
  
  BACKGROUND
  It remains unclear whether general health questionnaires or condition-specific surveys are superior for evaluating spine patients (Spine 2000;25:3100-3). Most clinicians would suspect that comorbidities (medical and psychosocial) play a significant role in the presentation, treatment, and outcome of spine patients. Yet, it has been difficult to quantify specifically the association of comorbidities with traditional health status instrument scores for spine patients.
  
  
  METHODS
  Initial visit (baseline) health questionnaires were analyzed. Patients were stratified according to the number of self-reported comorbidities. Analysis of variance was performed to assess the difference in mean health status across comorbidity groups. Multiple linear regressions were used to identify the most influential individual comorbidities on baseline functional survey scores.
  
  
  RESULTS
  There is an associated decrease in baseline physical component summary (PCS) (from the SF-36) and ODI scores with the addition of each comorbidity. For the range of zero to > or =7 comorbidities, the PCS score decreases from 33.3 to 23.2 (P < 0.001). The average baseline ODI score for patients with zero comorbidities was 62.4, decreasing to 42.0 in the group with > or =7 comorbidities (P < 0.001). The strongest association was seen with the medical comorbidities of smoking, frequent headaches, osteoarthritis, and osteoporosis (P < 0.001). However, the association with psychosocial comorbidities(e.g., self-rated health, active compensation case, depression) (P < 0.001) was higher for both health status measures. Health status measures in patients with lumbar problems show that these patients are more impacted by their disease than patients with cervical or thoracic spine problems (P < 0.001), although the correlation with comorbidities is smaller for the lumbar group (P < 0.001).
  
  
  CONCLUSIONS
  Traditional medical comorbidities correlate with both SF-36 (e.g., PCS) general health survey scores as well as disease-specific ODI scores. However, psychosocial comorbidities such as poor self-rated health (SF-1), an active compensation case, and low education level have a higher association than traditional medical comorbidities on these health status measures. The results show that the type of survey (disease-specific e.g., ODI, vs. generic e.g., SF-36) used may be less important than the need to assess and control for psychosocial and medical comorbidities when any patient-reported health survey is used in the spine population.
authors: Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA.
authors: James
authors: J
authors: Slover
authors: William A
authors: WA
authors: Abdu
authors: Brett
authors: B
authors: Hanscom
authors: Jon
authors: J
authors: Lurie
authors: James N
authors: JN
authors: Weinstein