Distance saturation product predicts health–related quality of life among sarcoidosis patients
Sarcoidosis is a chronic disease with different phenotypic manifestations. Health-related quality of life is an important aspect in sarcoidosis, yet difficult to measure. The objective of this study was to identify clinical markers predictive of poor quality of life in sarcoidosis patients that can be followed over time and targeted for intervention.
We assessed the quality of life of 162 patients with confirmed sarcoidosis in a prospective, cross-sectional study using the Sarcoidosis Health Questionnaire (SHQ) and Short Form-36 Health Survey (SF-36). We evaluated the validity of these questionnaires and sought to identify variables that would best explain the performance scores of the patients.
On multivariate regression analyses, the very best composite model to predict total scores from both surveys was a model containing the distance-saturation product and Borg Dyspnea Scale score at the end of a 6-min walk test. This model could better predict SF-36 scores (R2 = 0.33) than SHQ scores (R2 = 0.24). Substitution of distanced walked in 6 min for the distance-saturation product in this model resulted in a lesser ability to predict both scores (R2 = 0.26 for SF-36; R2 = 0.22 for SHQ).
Both the SHQ and SF-36 surveys are valuable tools in the assessment of health-related quality of life in sarcoidosis patients. The best model to predict quality of life among these patients, as determined by regression analyses, included the distance-saturation product and Borg score after the 6-min walk test. Both variables represent easily obtainable clinical parameters that can be followed over time and targeted for intervention.
Bourbonnais et al.: Distance saturation product predicts healthâ€“related quality of life among sarcoidosis patients. Health and Quality of Life Outcomes 2012 10:67. 22. ATS Committee on Proficiency Standards for Clinical Pulmonary Function Laboratories: ATS statement: guidelines for the six-minute walk test. Am J Respir Crit Care Med 2002, 166:111â€“117. Enright PL, Sherrill DL: Reference equations for six-minute walk in healthy adults. Am J Respir Crit Care Med 1998, 158:1384â€“1387. 23. 24. Mahler DA, Mackowiak JI: Evaluation of the short-form 36-item questionnaire to measure health-related quality of life in patients with COPD. Chest 1995, 107:1585â€“1589. 25. Martinez TY, Pereira CA, dos Santos ML, Ciconelli RM, Guimaraes SM, Martinez JA: Evaluation of the short-form 36-item questionnaire to measure health-related quality of life in patients with idiopathic pulmonary fibrosis. Chest 2000, 117:1627â€“1632. 26. Chang JA, Curtis JR, Patrick DL, Raghu G: Assessment of health-related quality of life in patients with interstitial lung disease. Chest 1999, 116:1175â€“1182.