Informal caregiving in COPD: A systematic review of instruments and their measurement properties

BACKGROUND: Increasing symptoms and activity restriction associated with COPD progression greatly impact on the lives of their informal caregivers, who play a vital role in maintaining their health. An understanding of this impact is important for clinicians to support caregivers and maintain a viable patient environment at home. This systematic review aimed to identify the instruments commonly used to assess informal caregiving in COPD and describe their measurement properties in this population. METHODS: Searches were conducted in PubMed, Scopus, Web of Science, CINAHL and PsycINFO and in references of key articles, until November 2016 (PROSPERO: CRD42016041401). Instruments used to assess the impact of COPD on caregivers were identified and their properties described. Quality of studies was rated using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist. Quality of the measurement properties of instruments was rated as 'positive', 'negative' or 'indeterminate'. RESULTS: Patients cared for, had moderate to very severe COPD and the sample of caregivers ranged from 24 to 406. Thirty-five instruments were used in fifty studies to assess caregivers' psychological status and mood (9 instruments), burden/distress (12 instruments), quality of life (5 instruments) or other (9 instruments). Eighteen studies assessed the measurement properties of 21 instruments, most commonly hypothesis testing (known validity) and internal consistency. Study quality varied from 'poor' to 'fair' and with many properties rated as 'indeterminate'. CONCLUSIONS: Although several instruments have been used to assess the impact of COPD on caregivers, an increased understanding of their properties is needed before their widespread implementation.