The profile of pain in older women with arthritis

Research Doctorate - Doctor of Philosophy (PhD)Arthritis covers a diverse group of diseases commonly involving degeneration and inflammation of the joints. It is very common, estimated to affect 18.5% of the Australian population, or approximately 3.9 million people. Although pain is the most prevalent presenting symptom in the very debilitating condition of arthritis, it has been insufficiently researched and therefore is not well understood, nor well managed in clinical practice. Traditionally, pain in arthritis has been attributed to peripheral, local tissue injury and the mechanism of nociceptive pain. However, the understanding of the experience of pain in arthritis is being increasingly broadened to include the complex interactions between nociceptive and neuropathic mechanisms. Recently, the Osteoarthritis Research Society International (OARSI) and the US Food and Drug Administration (FDA) have called for research to define the disease state of arthritis, and this includes the identification and evaluation of different types of pain in arthritis. The aim of this thesis was to explore the experience and impact of pain in arthritis. Specifically, this thesis focuses on the multi-dimensional nature of the experience of pain in older women with arthritis. This thesis by publication comprises a series of four papers, constituting elements of an integrated project. The flow of the thesis includes an introduction, chapters consisting of four inter-related papers, a discussion and a conclusion. Paper 1 is a systematic review of the literature on how the experience of pain is measured in older, community dwelling people with osteoarthritis. This paper concluded that the most commonly used measures of pain do not effectively assess the multi-dimensional nature of the experience of pain in osteoarthritis, nor have the majority of epidemiological studies in arthritis captured the multi-dimensional nature of the experience of pain in osteoarthritis. In acknowledging the findings from Paper 1, the <i>Profile of Pain in Older Women with Arthritis Study</i> was undertaken to better assess the multi-dimensional nature of the experience of pain in arthritis. Paper 2 outlines the study protocol for the <i>Profile of Pain in Older Women with Arthritis Study</i> and discusses the appropriateness of eleven measures of health, pain and arthritis used to explore the experience and impact of pain in arthritis. Paper 3 used data generated from the <i>Profile of Pain in Older Women with Arthritis Study</i> (Paper 2). Paper 3 reports that neuropathic-like pain in arthritis is common and is associated with greater disability and poorer quality of life. Furthermore, women who have arthritis and neuropathic-like pain have significantly more severe pain, a heightened pain experience and more fatigue. Abnormal sensory changes, higher pain catastrophizing and using more medications are significantly associated with neuropathic-like pain. Paper 4 identified three subgroups of older, community dwelling women with arthritis with very different, very distinct profiles of pain. Profiles consisted of 39.5% of women having uni-dimensional pain, 38.6% of women having moderate multi-dimensional pain and 21.9% of women having severe multi-dimensional pain. Once profiles were identified, women with moderate and severe multi-dimensional pain profiles were at a significantly greater risk of poorer physical and mental health related quality of life. This thesis has explored the experience and impact of pain in arthritis. The papers presented provide a significant and important contribution to the field of arthritis and pain, by providing preliminary evidence on the identification and evaluation of different types of pain in arthritis. The next challenge is in the study of the treatment of pain mechanisms in arthritis. This area of research has great promise to improve pain management and decrease the significant socio-economic burden associated with arthritis