Recruitment to a clinical trial from the databases of specialists in Parkinson's disease

Many clinical trials involving elderly people living at home suffer from low recruitment. We report our experience of recruiting people with Parkinson's disease (PD) from specialist clinical databases, to a randomised controlled trial of personalized exercise.

We aimed to recruit 200 repeat fallers with PD. Subjects were recruited through the clinical registers of specialists in PD in two NHS trusts. They had to have a confirmed diagnosis of PD, be independently mobile, live in the community, be a repeat faller, and were screened for cognitive impairment.

Out of 1107 patients on the registers, 457 did not meet the eligibility criteria for the trial. A further 151 were excluded for other reasons. Four hundred and ninety-nine were approached to have a home screening visit: 405 replied and 305 agreed to be screened for the trial. Of those screened, 126 were non-repeat fallers and 22 failed other eligibility criteria. Out of the remaining 157 patients, 18 (11%) decided not to participate in the trial which left 139 recruited to the trial. Seven more were recruited from a second screen of previous non-repeat fallers. In total 146 patients were recruited: 142 to the main trial and four to the initial pilot phase.

The percentage of patients who participated in the main trial was only 13% (95% confidence interval 11% to 15%) of those on specialists' registers, considerably less than estimated, although the proportion of fallers and repeat fallers was similar to that previously reported.