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In the past three decades, health-related quality of life (HRQoL) has become an outcome variable in Parkinson’s disease clinical trials. This review considers the measuring tools that have been developed, suitability of data reporting, complexity of outcome interpretation, and clinical application to provide evidence regarding available therapeutic interventions to date. In the introduction, different terms regarding quality of life are clearly defined. The methodology section offers an overview of generic, disease specific, and recommended HRQoL scales in Parkinson’s disease and the most important psychometric attributes a scale should meet. The interpretation of HRQoL outcomes is complex and not intuitive. Thus, appropriate reporting of data is crucial in order to calculate relative change, a result that facilitates understanding to what extent an intervention is beneficial. The concept of minimally important change/difference is explained as well as the different approaches to its calculation (anchor-based and distribution-based methods). In the results section, a brief overview of the impact on HRQoL of currently available treatments in Parkinson’s disease is provided. Special emphasis is given to data assessment, highlighting reports that helped understanding of the clinical significance of the intervention and therefore aided in making therapeutic decisions. The discussion section emphasizes the need for more clinical trials with HRQoL as a primary outcome and standardized reporting in order to further our understanding of the complexity of treatment effects and make evidence-based clinical decisions regarding HRQoL in patients with Parkinson’s disease. [ABSTRACT FROM PUBLISHER]

Abstract: Dopamine receptor agonists have demonstrated effectiveness in managing Parkinson''s disease both as monotherapy and as adjunctive treatment to l-dopa. Dopamine receptor agonist therapy may reduce the risk of developing motor complications; however, it can also produce undesirable side-effects. Patient health-related quality of life (HRQoL) is a comprehensive outcome that may be useful in evaluating these complex effects. This is a systematic review of the reported clinical trials that have investigated the effect of dopamine receptor agonists on HRQoL. A literature search was carried out using Medline, cut-off date 30 June 2009. Identified manuscripts were classified according to level of evidence; Level I studies were rated for quality; relative change (RC) and effect size (ES) were calculated when possible; and dopamine receptor agonist efficacy in improving HRQoL was assigned accordingly. Overall, 18 manuscripts reporting clinical trial outcomes on seven dopamine receptor agonists were reviewed. Six studies were randomized and double-blinded; five were controlled with placebo; and 10 were comparative. Sample sizes ranged from 4 to 506 patients (mean, 181.1 ± 143.7), and follow-up ranged from 1.5 to 48 months (11.8 ± 14.2). Level I was reached by six of eight pramipexole studies (mean quality, 79%), one of four cabergoline studies (quality, 83.3%), and one study with the following: ropinirole prolonged release (quality, 88.9%), pergolide (quality, 86.0%), and rotigotine (quality, 77.8%). Quantifying HRQoL improvement by RC and ES was only possible for five of the 18 studies. The reviewed trials were highly variable in design, objectives and presentation of results. Therefore, specific evaluation of intervention impact in each of the tested clinical settings was required. [Copyright &y& Elsevier]