Measuring health-related quality of life in adults with chronic conditions in primary care settings – PMC

Measurement of HRQOL in adults with chronic conditions can support patient management and contribute to primary care service evaluation. Scales that are based on a broad definition of health and that address the individualized nature of HRQOL are appropriate for these purposes, such as the WHOQOL-BREF. Psychometric evidence supports using this scale for adults with chronic conditions; more information about its responsiveness is needed.

Early HRQOL approaches focused on health and functional status while recent approaches incorporate individualized concepts such as the person’s own values and the environment. The abbreviated World Health Organization Quality of Life Scale (WHOQOL-BREF), the 36-Item Short Form Health Survey (SF-36), and the Duke Health Profile were critiqued. All address physical, mental, and social domains, while the WHOQOL-BREF also addresses environment. Psychometric evidence supports use of the SF-36 and WHOQOL-BREF with this population. The SF-36 has the most evidence of responsiveness but has some floor and ceiling effects, while the WHOQOL-BREF does not appear to have floor or ceiling effects but has limited evidence of responsiveness. The WHOQOL-BREF has the highest proportion of individualized items.

Scales were selected if they were designed for clinical use; were easy to administer; were generic and broad in content areas; and contained some individualized items. Scales were critiqued according to content development, theoretical basis, psychometric properties, scoring, feasibility, the concepts being measured, and the number of items that measured an individualized concept.

As primary care transforms across Canada, greater emphasis is being placed on quality of care and accountability for outcomes, as well as on prevention and management of chronic conditions and patient self-management.1 Typical indicators of patient outcomes (such as blood pressure or smoking rate) do not capture the breadth of services that are being provided in primary care, nor do they provide enough detail to guide quality improvement. Health-related quality of life (HRQOL) is a concept that can be useful in evaluation and improvement efforts. This paper will provide guidance to primary care providers regarding the use of HRQOL instruments in practice for adults with chronic conditions.

Health-related quality of life is defined as those aspects of quality of life (QOL) that directly or indirectly relate to health.2,3 While the terms quality of life and health-related quality of life are often used interchangeably, the 2 are generally considered distinct concepts. Quality of life can be considered overall satisfaction with life, either as a single concept4 or broken down into domains.5 Health-related quality of life is a narrower concept that includes physical, psychological, and social domains6,7 and can be considered one’s subjective assessment of the physical, psychological, and social domains of health.7 Health-related quality of life scales can measure the results of health care, supplementing traditional physiologic measures of health status.8

Health-related quality of life scales might be specific, applying to certain conditions, populations, or functional issues, or they might be generic. Generic scales are preferred when measuring HRQOL in people with comorbidities9 or when evaluating multicomponent interventions. They have similar or better responsiveness to change compared with disease-specific scales.10–13 Generic scales include health profiles, which generate scores in a number of different domains, and health utility measures, which generate a single score of HRQOL such as a quality-adjusted life-year.6 Although the reliability of patient-reported outcomes such as HRQOL might be challenged, most common clinical tools have similar levels of error to patient-reported outcome measures.14 Adults with chronic conditions such as arthritis, chronic obstructive pulmonary disease (COPD), congestive heart failure, diabetes, hypertension, and heart disease experience lower HRQOL than people without these conditions do15–18; the presence of comorbidity further decreases HRQOL.19–22 Presence of chronic conditions relates to a number of HRQOL domains such as increased pain23 and difficulties in physical function,9,24 mental health,25 general health, social function,26 home management,27 energy, and sleep.28 All of these domains can be affected by primary care services (eg, pain medication, mental health counseling, and self-management education to assist in managing daily activities). Measuring HRQOL can be an important component of evaluating primary care services, including complex processes such as intervention dose-response relationships.29

In addition to evaluating service outcomes, measuring HRQOL in adults with chronic conditions can promote high-quality patient care. Health-related quality of life scales capture the patient’s perspective, a key aspect of providing the patient-centred, collaborative care that is important to patients30,31; this type of care can also create positive outcomes for patients such as improved self-management skills.32 Measuring HRQOL can improve clinician awareness of patient concerns and patient-clinician communication,33,34 supporting service and program planning. Measuring HRQOL can also improve patient HRQOL itself.35

To appropriately select and use HRQOL scales, it is important to understand the conceptual basis, concepts measured, and psychometric properties of HRQOL scales. While most HRQOL scales cover mental, physical, and social domains, the scales’ items might address different concepts. For example, one scale might ask about difficulty sleeping, while another might ask about satisfaction with sleep. The latter concept is more “subjective” or individualized and related to the person’s own life.36 Previous reviews of HRQOL scales have described the psychometric properties and domains of the scales37 or the conceptual model underpinning each scale.38 No previous review has closely examined the concepts being measured or use of HRQOL scales for adults with a range of chronic conditions in primary care settings. To fill these gaps and assist primary care practitioners in using HRQOL scales, the objectives of this paper are to describe approaches to conceptualizing HRQOL, critically review 3 commonly used HRQOL scales relevant to adults with chronic conditions in primary care settings, and make recommendations for using HRQOL scales in primary care practice.