Fallibility of Optometric Patients Recall of Spectacle Prescription Changes

Abstract

Purpose Practising optometrists and vision researchers often rely on the patient's recollection of past optometric events to compile a refractive history. The work reported here attempted to evaluate the reliability of such an approach in a clinical population by comparing self-report of previous spectacle prescription change against actual recorded refractive details. Methods A documented healthy clinical population with mildmoderate myopia habitually corrected by spectacles was invited to complete a short tick-box questionnaire. Subjective recall of spectacle prescription changes over the past five years was investigated. Subsequently, these recollections were compared against individual recorded optometric histories. Results 155 persons (42% of those canvassed: mean age 36.2± 9.1 years) responded to the invitation to complete the questionnaire. The subjective estimate of the interval since the most recent sight test was accurate ( P=0.7). However the question “Has your distance glasses prescription been changed over the past five years?” had a sensitivity of 0.67/specificity of 0.64, and a positive predictive value (PV) of 0.43/negative PV of 0.82. With a calculated value of K= 0.25, the strength of the agreement between subjective recall and the actual record could at best only be regarded as “Fair”. Conclusions The accuracy of subjective recollection as an indication of refractive change over an immediately-preceding time interval of several years must be treated with caution. Whether questioning patients in the optometric practice or establishing the background of participants in a clinical vision research project, there is no substitute for reference to a contemporary record detailing refractive history.