RESEARCH PAPER The effect of disability on personal quality of primary care received by older adults CHUN-JU HSIAO 1 , KAREN BANDEEN-ROCHE 2 , JILL A. MARSTELLER 1 ,& BRUCE A. LEFF 3 1 Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA, 2 Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA, and 3 Division of Geriatric Medicine and Gerontology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA Accepted February 2009 Abstract Purpose. To quantify the association between disability and patient-rated personal quality of primary care among older adults. Methods. Participants were community-dwelling Medicare beneficiaries aged 65 enrolled in traditional Medicare or a Medicare health maintenance organisations. Functional status was evaluated twice (1998 and 1999) using nine activities of daily living (ADLs) and instrumental ADLs. Respondents were classified as having no, persistent, incident or previous disability based on the combination of their functional statuses at the two measurements. Self-reported personal quality of primary care was assessed using the Primary Care Assessment Survey in five domains. Results. Compared to those with no disability, respondents with previous disability reported lower quality of care by 0.497 (p ¼ 0.001) of a standard deviation, whereas persistent or incident disability was not associated with a difference in personal quality of care. Conclusions. Previous disability appears to have a negative effect on the personal quality of care while incident and persistent disability do not. Findings for previous and incident disability may suggest a lag in the perception of quality of care. A ‘response shift’ phenomenon may explain the lack of an observed association between persistent disability and personal quality of care. Keywords: Quality of care, physician–patient relationship, functional status, patient-centred care Introduction Advances in medicine and improvements in health have contributed to longer life expectancies for older persons than their counterparts experienced only a few decades ago. These and other demographic trends will lead, in many countries, to a ‘gerontolo- gical explosion’ – a significant expected increase in the older population in the next 50 years [1]. In 2000, 35 million people in the United States aged 65 and over and the number is expected to double by 2030 [2]. In addition, the number of those who are 85 and over, the oldest old, who are at greatest risk for frailty and chronic disease, is expected to increase fivefold between 2000 and 2050 due to aging of the baby boomers [3]. A large portion of the older population suffers from at least one chronic illness or disability [4]. Among community-dwelling adults aged 75 years and older, approximately 10% require help with activities of daily living (ADL), and 19% require help with instrumental activities of daily living (IADL) [5]. In this article, we define disability as ‘a relational concept that describes any restriction or lack of ability to perform an activity in the manner or within the range considered normal for a human being’ [6–8]. The 1997 IOM modified model, used here, emphasises that disability is not an individual Correspondence: Chun-Ju Hsiao, Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, 624 North Broadway, Room 433, Baltimore, MD 21205, USA. Tel: þ410-409-5935. Fax: þ410-955-3249. E-mail: cjhsiao@jhsph.edu Disability and Rehabilitation, 2009; 31(22): 1835–1842 ISSN 0963-8288 print/ISSN 1464-5165 online ª 2009 Informa UK Ltd. DOI: 10.1080/09638280902811727