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Most economic evaluations of health care programmes do not consider the effects of informal care, while this could lead to suboptimal policy decisions. This study investigates the construct validity of the CarerQol instrument, which measures and values carer effects, in a new population of informal caregivers.
A questionnaire was distributed by mail (n = 1,100, net response rate = 21%) to regional informal care support centers throughout the Netherlands. Two types of construct validity, i.e., convergent and clinical validity, have been analyzed. Convergent validity was assessed with Spearman’s correlation coefficients and multivariate correlation between the burden dimensions (CarerQol-7D) and the valuation component (CarerQol-VAS) of the CarerQol. Additionally, convergent validity was analyzed with Spearman’s correlation coefficients between the CarerQol and other measures of subjective caregiver burden (SRB, PU). Clinical validity was evaluated with multivariate correlation between CarerQol-VAS and CarerQol-7D, characteristics of caregivers, care recipients and care situation among the whole sample of caregivers and subgroups.
The positive (negative) dimensions of CarerQol-7D were positively (negatively) related to CarerQol-VAS, and almost all had moderate strength of convergent validity. CarerQol-VAS was positively associated with PU and negatively with SRB. The CarerQol-VAS reflects differences in important background characteristics of informal care: type of relationship, age of the care recipient and duration of care giving were associated with higher CarerQol-VAS scores. These results confirmed earlier tests of the construct validity of the CarerQol. Furthermore, the dimensions of CarerQol-7D significantly explained differences in CarerQol-VAS scores among subgroups of carers.
Notwithstanding the limitations of our study, such as the low response rate, this study shows that the CarerQol provides a valid means to measure carer effects for use in economic evaluations. Future research should derive a valuation set for the CarerQol and further address the instrument’s content validity, sensitivity and reliability.
Schellingerhout, R. (2003). The informal caregiver. In J. Timmermans (Ed.), Informal care. Care of and to informal carers (pp. 33–57). The Hague: SCP.
Broese van Groenou, M., & De Boer, A. (2009). Findings: Burden of informal carers. In A. De Boer, M. Broese, J. van Groenou, & J. Timmermans (Eds.), Informal care. An overview of the support given by and to informal carers in 2007 (pp. 144–165). The Hague: SCP.
Schellingerhout, R. (2003). Extra expenses and loss of income. In J. Timmermans (Ed.), Informal care. Care of and to informal carers (pp. 163–206). The Hague: SCP.
Hoefman, R. (2009). Care providers. In A. De Boer, M. Broese, J. van Groenou, & J. Timmermans (Eds.), Informal care. An overview of the support given by and to informal carers in 2007 (pp. 29–44). The Hague: SCP.
Broese van Groenou, M., & De Boer, A. (2009). Findings: Positive experiences. In A. De Boer, M. Broese, J. van Groenou, & J. Timmermans (Eds.), Informal care. An overview of the support given by and to informal carers in 2007 (pp. 167–183). The Hague: SCP.
Gold, M. R., Siegel, J. E., Russell, L. B., & Weinstein, M. (1996). Cost-effectiveness in health and medicine. New York: Oxford University Press.
Drummond, M. F., Sculpher, M. J., Torrance, G. W., O’Brien, B. J., & Stoddart, G. L. (2005). Methods for the economic evaluation of health care programmes. New York: Oxford University Press.
College voor Zorgverzekeringen (CVZ). (2005). Guidelines for pharmaco-economic research; evaluation and actualisation [richtlijnen voor farmaco-economisch onderzoek; evaluatie en actualisatie]. Diemen: CVZ.
van Exel, J., Koopmanschap, M., & Brouwer, W. (2003). Kostbaar ontslag. Korte verpleegduur brengt mantelzorgers in de problemen. Medisch Contact, 58(34), 1272–1274.
National Institute for Clinical Excellence. (2008). Guide to the methods of technology appraisal. London: NICE.
National Institute for Clinical Excellence. (2009). NICE technology appraisal guidance 111. Donepezil, galantamine, rivastigmine (review) and memantine for the treatment of Alzheimer’s disease (amended). London: NICE.
de Meijer, C., Brouwer, W., Koopmanschap, M., van den Berg, B., & van Exel, J. (2009). The value of informal care-a further investigation of the feasibility of contingent valuation in informal caregivers. Health Economics, 19, 755–771. CrossRef
EuroQol Group. (1990). EuroQol—a new facility for the measurement of health-related quality of life. Health Policy, 16(3), 199–208. CrossRef
Brouwer, W. B. F., Van Exel, N. J. A., & Tilford, M. J. (2010). Incorporating caregiver and family effects in economic evaluations of child health. In W. J. Ungar (Ed.), Economic evaluation in child health. Oxford: Oxford University Press.
Robinson, B. C. (1983). Validation of a caregiver strain index. Journal of Gerontology, 38(3), 344–348. PubMed
van Exel, N. J., Scholte op Reimer, W. J., Brouwer, W. B., van den Berg, B., Koopmanschap, M. A., & van den Bos, G. A. (2004). Instruments for assessing the burden of informal caregiving for stroke patients in clinical practice: A comparison of CSI, CRA, SCQ and self-rated burden. Clinical Rehabilitation, 18(2), 203–214. PubMedCrossRef
Frey, B. S., & Stutzer, A. (2002). What can economists learn from happiness research? Journal of Economic Literature, 40, 402–435. CrossRef
Ferrer-i-Carbonell, A., & Frijters, P. (2004). How important is methodology for the estimates of the determinants of happiness? The Economic Journal, 114, 641–659. CrossRef
Veenhoven, R. (1984). Conditions of happiness. Dordrecht: Kluwer.
De Vaus, D. A. (2002). Surveys in social research. St. Leonards: Allen & Unwin.
Cohen, J. (1988). Statistical power analysis for the behavioral sciences. New Jersey: Lawrence Erlbaum.
Hopkins, W. G. (2002). A new view of statistics: Effect magnitudes. http://www.sportsci.org/resource/stats/effectmag.html.
Svensson, E. (2000). Comparison of the quality of assessments using continuous and discrete ordinal rating scales. Biometrical Journal, 4, 417–434. CrossRef
van Exel, J., Moree, M., Koopmanschap, M., Goedheijt, T. S., & Brouwer, W. (2006). Respite care—an explorative study of demand and use in Dutch informal caregivers. Health Policy, 78(2–3), 194–208. PubMed
Veenhoven, R. (2009). World database of happiness, distributional findings in nations. http://worlddatabaseofhappiness.eur.nl.
- A new test of the construct validity of the CarerQol instrument: measuring the impact of informal care giving
Renske J. Hoefman
N. Job A. van Exel
Sandra Looren de Jong
W. Ken Redekop
Werner B. F. Brouwer
- Springer Netherlands