Assessing health-related quality of life in COPD: comparing generic and disease-specific instruments with focus on comorbidities

Abstract

BackgroundChronic Obstructive Pulmonary Disease (COPD) influences different aspects of patient’s health-related quality of life (HRQL). While disease-specific HRQL instruments focus on symptoms and functional impairments, generic instruments cover a broader view on health. This study compares the generic EQ-5D-3 L and two disease-specific questionnaires (St.-George’s Respiratory Questionnaire (SGRQ-C), COPD Assessment Test (CAT)) in a comprehensive spectrum of COPD disease grades with particular attention on comorbidities and assesses the discriminative abilities of these instruments.MethodsUsing data from the baseline visit of the German COPD cohort COSYCONET, mean HRQL scores in different COPD grades were compared by linear regression models adjusting for age, sex, education, smoking status, BMI, and low vs. high number of comorbidities or a list of several self-reported comorbid conditions. Discriminative abilities of HRQL instruments to differentiate between COPD grades were assessed by standardized mean differences.ResultsIn 2,291 subjects in COPD GOLD grades 1–4 EQ-5D-3 L utility, EQ-5D VAS, SGRQ, and CAT were found able to discriminate between COPD grades, with some limitations for the EQ-5D utility in mild disease. Both generic and disease-specific HRQL instruments reflected the burden of comorbid conditions. The SGRQ showed the best discrimination between COPD grades and was less influenced by comorbidities, while EQ-5D utility put a higher weight on comorbid conditions. For all instruments, psychiatric disorders and peripheral artery disease showed the strongest negative associations with HRQL.ConclusionAll HRQL instruments considered reflect considerable impairment of HRQL in COPD patients, worsening with increasing COPD grade and number of comorbidities. Findings may support clinical assessment, choice of HRQL instrument in future studies, and parameterization of decision-analytic models.Electronic supplementary materialThe online version of this article (doi:10.1186/s12890-016-0238-9) contains supplementary material, which is available to authorized users.

Association of generic health-related quality of life (EQ-5D dimensions) and inactivity with lung function in lung-healthy German adults: results from the KORA studies F4L and Age

“…Data from the German COPD cohort COSYCONET showed a decrease in mean EQ-5D utility 305 with increasing COPD grade, i.e. from 0.85 in COPD grade 1 to 0.74 in COPD grade 4 [29]. 306 Our mean EQ-5D utility of 0.91 in lung-healthy subjects fits to the lower results reported for 307 the COPD cohort.…”

“…Interestingly, despite the high overall utility score of EQ-5D in our study 308 population, associations were still detectable for problems in mobility or usual activities, 309 and being inactive. This is further supported by a carefully extended analysis considering the 310 findings of the COPD cohort by Wacker et al [29]. According to the observed utility score in 311 GOLD grade I, we categorized the EQ-5D utility in our population in three groups: (1) those 312 with best health (0.999, used as the reference group), (2) those with a still slightly greater 313 utility (≥0.887) than the mean of COPD grade 1 in Wacker et al [29], and those with 314 comparable EQ-5D utility (<0.887).…”

“…This is further supported by a carefully extended analysis considering the 310 findings of the COPD cohort by Wacker et al [29]. According to the observed utility score in 311 GOLD grade I, we categorized the EQ-5D utility in our population in three groups: (1) those 312 with best health (0.999, used as the reference group), (2) those with a still slightly greater 313 utility (≥0.887) than the mean of COPD grade 1 in Wacker et al [29], and those with 314 comparable EQ-5D utility (<0.887). In a linear regression analysis adjusting for sex, age, 315 height and weight, subjects in the lower EQ-5D category had a -87 ml (95% CI: -160; -15) 316 lower FEV 1 and -96 (95% CI: -187; -4) lower FVC compared to those with the best possible 317 utility.…”

Peripheral Artery Disease and Its Clinical Relevance in Patients with Chronic Obstructive Pulmonary Disease in the COPD and Systemic Consequences–Comorbidities Network Study

“…A MCID for the EQ-5D-3L utility score is not yet established, but may range between 0.08 and 0.10 according to studies in patients without COPD (30)(31)(32). In a previous analysis of the COSYCONET data set comparing disease-specific and generic health status instruments, the SGRQ showed the best discrimination between COPD grades, and was less influenced by self-reported comorbidities, whereas the EQ-5D-3L utility had a higher weight on self-reported comorbid conditions (33).…”

The direct and indirect costs of managing chronic obstructive pulmonary disease in Greece

“…In 2012, it was the third leading cause of death, accounting for 5.6% of all deaths 2. The impairment of health-related quality of life (HRQoL) in patients with COPD is considerable and has been shown to increase with disease severity 3. The prevalence of COPD varies globally between 8% and 10% in the adult population 4.…”