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.

Keywords

• optometric patient
• predictive value
• questionnaire
• refractive history
• sensitivity
• specificity