Determining the quality and effectiveness of surgical spine care: patient satisfaction is not a valid proxy

Abstract

Background context: Given the unsustainable costs of the US health-care system, health-care purchasers, payers, and hospital systems are adopting the concept of value-based purchasing by shifting care away from low-quality providers or hospitals. Legislation now allows public reporting of these quality rankings. True measures of quality, such as surgical morbidity and validated questionnaires of effectiveness, are burdensome and costly to collect. Hence, patients' satisfaction with care has emerged as a commonly used metric as a proxy for quality because of its feasibility of collection. However, patient satisfaction metrics have yet to be validated as a measure of overall quality of surgical spine care.

Purpose: We set out to determine whether patient satisfaction is a valid measure of safety and effectiveness of care in a prospective longitudinal spine registry.

Study design: Prospective longitudinal cohort study.

Patient population: All patients undergoing elective spine surgery for degenerative conditions over a 6-month period at a single medical center.

Outcome measures: Patient-reported outcome instruments (numeric rating scale [NRS], Oswestry disability index [ODI], neck disability index [NDI], short-form 12-item survey [SF-12], Euro-Qol-5D [EQ-5D], Zung depression scale, and Modified Somatic Perception Questionnaire [MSPQ] anxiety scale), return to work, patient satisfaction with outcome, and patient satisfaction with provider care.

Methods: All patients undergoing elective spine surgery for degenerative conditions over a 6-month period at a single medical center were enrolled into a prospective longitudinal registry. Data collected on all patients included demographics, disease characteristics, treatment variables, readmissions/reoperations, and all 90-day surgical morbidity. Patient-reported outcome instruments (NRS, ODI, NDI, SF-12, EQ-5D, Zung depression scale, and MSPQ anxiety scale), return to work, patient satisfaction with outcome, and patient satisfaction with provider care were recorded at baseline and 3 months after treatment. Receiver-operating characteristic (ROC) curve analysis was performed to determine whether extent of improvement in quality of life (SF-12 physical component summary [PCS]) and disability (ODI/NDI) accurately predicted patient satisfaction versus dissatisfaction. Standard interpretation of area under the curve (AUC) was used: less than 0.7, poor; 0.7 to 0.8, fair; and greater than 0.8, good accuracy. Multivariate logistic regression analysis was performed to determine if surgical morbidity (quality) or improvement in disability and quality of life (effectiveness of care) were independently associated with patient satisfaction.

Results: Four hundred twenty-two (84%) patients completed all questionnaires 3 months after surgery during the reviewed time period (mean age 55±14 years). Lumbar surgery was performed in 287 (68%) and cervical surgery in 135 (32%) patients. There were 51 (12.1%) 90-day complications, including 21 (5.0%) readmissions and 12 (2.8%) return to operating room. Three hundred fifty-eight (84.8%) patients were satisfied with provider care and 288 (68.2%) with their outcome. Satisfaction with provider care: In ROC analyses, extent of improvement in quality of life (SF-12) and disability (ODI/NDI) differentiated satisfaction versus dissatisfaction with care with very poor accuracy (AUC 0.49-0.69). In regression analysis, 3-month morbidity (odds ratio [95% confidence interval]: 1.45 [0.79-2.66]), readmission (0.66 [0.24-1.80]), improvement in quality of life (SF-12 PCS), or improvement in general health (health transition index) were not associated with satisfaction with care. Satisfaction with outcome: In ROC analyses, improvement in quality of life (SF-12) and disability (ODI/NDI) failed to differentiate satisfaction with good accuracy (AUC 0.76). Neither 90-day morbidity (1.05 [0.46-2.34]) nor 90-day readmission (0.27 [0.04-2.04]) was associated with satisfaction with outcome in regression analysis.

Conclusions: Patient satisfaction is not a valid measure of overall quality or effectiveness of surgical spine care. Patient satisfaction metrics likely represent the patient's subjective contentment with health-care service, a distinct aspect of care. Satisfaction metrics are important patient-centered measures of health-care service but should not be used as a proxy for overall quality, safety, or effectiveness of surgical spine care.

Keywords: Patient satisfaction; Patient-reported outcome measures; Spine surgery.