Gastrointestinal disorders in Parkinson's disease: prevalence and health outcomes in a US claims database.

The majority of patients with Parkinson's Disease (PD) will eventually develop gastrointestinal disorders (GIDs) such as dysphagia, constipation and gastroesophageal reflux. The objectives of this study were to examine the incidence of GIDs in PD patients in a US population, and to examine subsequent PD-related outcomes in patients with GIDs. In a US administrative health claims database, GID incidence increased over time to reach 65% at four years after PD diagnosis. To further investigate this relationship, a subset of patients was analysed in greater detail. Continuously treated PD patients with and without GIDs were matched by age, gender, comorbidities, treatment regime, US region and plan type. Their emerging health outcomes were followed up for two years. Outcomes included neuropsychiatric, motor and urogenital disturbances, as well as healthcare utilization and costs. Patients with GIDs had higher rates of psychosexual dysfunction, anxiety, depression, ataxia, pain, movement disorders, urinary incontinence and falls. Emergency room admissions, the number of drugs for pain, sleep and depression, PD-related healthcare costs and non PD-related healthcare costs also increased during the observation period in GID patients. This study indicated that GIDs may be associated with deleterious effects on some PD-related outcomes.