Abstract
Abstract: :
Purpose: Nation-wide population based active surveillance systems are effective for ascertaining cases and facilitating the epidemiological investigation of rare conditions in other specialties. We report upon the evaluation of the first 3 years activities of an active surveillance system of rare eye conditions in the United Kingdom (UK). Methods: This scheme involves all ophthalmologists with clinical autonomy in the UK. The evaluation assessed participation rates, study applications and research outputs. In addition opinions of ophthalmologists were sought through an anonymous postal survey. This collected information on the usefulness, levels of feedback, barriers to participation and levels of case ascertainment achieved through the surveillance scheme. Results: Over the first 3 years, the 4-month mean participation rate improved from 58% to 71%. An association between higher individual card return rates and an increased likelihood that a returned card reported a case was identified (p<0.001). 10 studies used this system for case ascertainment with further applications being assessed. To date 4 journal publications and 14 conference presentations have reported findings from these studies. 582/870 (68%) questionnaires were returned by ophthalmologists. 95% considered this surveillance system as very or quite useful. 71% reported overall feedback to be sufficient. However, 34% requested greater feedback from the research groups. Difficulty with identifying previously reported cases (52%) and paying for return postage of cards (22%) were reported as barriers to effective participation. 72% of respondents did not consider the work involved in reporting a case to be prohibitive. Self-reported levels of case ascertainment by ophthalmologists for completed studies ranged between 72% and 95%. Conclusion: This evaluation demonstrates that active surveillance is a suitable method for the investigation of rare ophthalmic conditions and it currently receives a high level of support from UK ophthalmologists. This population based surveillance system provides an effective method for prospective case identification and subsequent data collection. It enables the study of sufficiently representative samples to allow meaningful epidemiological analysis and to avoid the bias that can occur through using non-population based methods or retrospective surveys .
Keywords: 350 clinical (human) or epidemiologic studies: biostatistics/epidemiology methodology • 354 clinical (human) or epidemiologic studies: prevalence/incidence • 353 clinical (human) or epidemiologic studies: outcomes/complications