The development and validation of the Parkinson’s disease questionnaire and related measures

© Cambridge University Press 2011. Introduction Parkinson's disease can have a wide range of impacts on individuals' lives. Although the range of problems has been documented, attempts to assess such impacts systematically and directly from the individual's perspective are relatively recent. This chapter outlines the development of a questionnaire designed to measure health-related quality of life in patients diagnosed with Parkinson's disease, as well as the subsequent development of a shorter-form measure of this instrument. Parkinson's disease (PD) is a common, chronic neurological condition affecting just over 1 per 1000 and increasing in incidence in older ages. Early diagnosis can prove difficult but is usually defined by the presence of at least two of the primary physical symptoms (tremor, rigidity, bradykinesia, and postural instability), as well as a positive response to the drug levodopa. Primary symptoms can manifest themselves in many ways, including slowness, stiffness, an inability to initiate movement, a stooped posture, an impassive face, and a shuffling gait. Difficulties may be observed with walking and balance, dressing, and speech and communication, along with loss of dexterity or fatigue. As the disease progresses, the physical symptoms may affect other aspects of daily life and create additional psychological and social problems. Currently, no cure for PD is known, although pharmaceutical and surgical treatments can be effective in managing some of the symptoms. Therefore the aim of any treatment must primarily be to improve quality of life.