Novel linkage approach to join community-acquired and national data.

BACKGROUND: Community optometrists in Scotland have performed regular free-at-point-of-care eye examinations for all, for over 15 years. Eye examinations include retinal imaging but image storage is fragmented and they are not used for research. The Scottish Collaborative Optometry-Ophthalmology Network e-research project aimed to collect these images and create a repository linked to routinely collected healthcare data, supporting the development of pre-symptomatic diagnostic tools. METHODS: As the image record was usually separate from the patient record and contained minimal patient information, we developed an efficient matching algorithm using a combination of deterministic and probabilistic steps which minimised the risk of false positives, to facilitate national health record linkage. We visited two practices and assessed the data contained in their image device and Practice Management Systems. Practice activities were explored to understand the context of data collection processes. Iteratively, we tested a series of matching rules which captured a high proportion of true positive records compared to manual matches. The approach was validated by testing manual matching against automated steps in three further practices. RESULTS: A sequence of deterministic rules successfully matched 95% of records in the three test practices compared to manual matching. Adding two probabilistic rules to the algorithm successfully matched 99% of records. CONCLUSIONS: The potential value of community-acquired retinal images can be harnessed only if they are linked to centrally-held healthcare care data. Despite the lack of interoperability between systems within optometry practices and inconsistent use of unique identifiers, data linkage is possible using robust, almost entirely automated processes.

Referrals from community optometrists in England and their replies: A mixed methods study.

PURPOSE: Community optometrists, through routine eye examinations, identify patients with disease or ocular abnormalities requiring referral to the Hospital Eye Service. In many cases no reply to the referral letter is received, resulting in some patients being re-referred unnecessarily, potentially increasing the number of other patients who lose sight whilst on hospital waiting lists. This study investigated, qualitatively and quantitatively, factors influencing optometric referrals and replies. METHODS: The three-phase, sequential mixed methods study started with a literature review and qualitative phase, interviewing stakeholders to identify issues for exploration in subsequent phases. The second, quantitative phase, undertook documentary analysis of 349 patient referral records from three optometric practice modalities (domiciliary, independently owned, and corporate chain) in England. A final qualitative phase obtained views from stakeholders to explore unexplained findings from the first two phases. RESULTS: Phase 1 identified communication, financial, professional and technological issues for further exploration. In Phase 2, the referral rate was 22.2% for domiciliary provider, 2.1% for independent practice and 2.5% for the corporate chain, with the variation most likely explained by patient age and associated ophthalmic disease, illness and disability. The referral reply rate was 5.7% for domiciliary provider, 25.0% for independent practice and 4.9% for the corporate chain. The community optometrist remained unaware of the outcome of their referral in 72.8% of cases. Qualitative analyses indicate the main factors influencing referral reply rates are technology, the General Medical Practitioner, community optometrists' utility to and utility of the National Health Service and patient mobilisation. CONCLUSIONS: The low referral reply rate creates a break in the feedback loop required to raise the standard of referrals and avoid unnecessary re-referral. Of the factors identified that influence referral reply rates, technology is key in view of the increasing use of online referral platforms. Feedback to the referring optometrist should be embedded in such systems.