Cognitive heuristics in the operating room: the role of ‘left-digit bias’ in ophthalmic surgical selection

Introduction Left-digit bias is a cognitive heuristic in which the leftmost digit of a number disproportionately influences judgment. This study evaluates the impact of perceived patient age on ophthalmic surgical decision-making. Methods Using a multicentre federated electronic health record network, patients aged 40–85 years with a routine health visit, followed by at least 1 documented ophthalmic examination and a diagnosis code specific to the surgical outcome under study, were followed for 1 year. Patients were grouped into consecutive 2-year age cohorts and matched 1:1 on demographic characteristics, healthcare utilisation, systemic comorbidities, and ocular diagnoses and procedures. Prespecified decade-boundary comparisons were 48/49 versus 50/51, 58/59 versus 60/61, and 68/69 versus 70/71. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for each surgical outcome. Results Among 8,156,608 eligible patients, 218,816 (2.68%) underwent an included ophthalmic procedure, including 201,591 phacoemulsification procedures. The younger cohort had lower odds of phacoemulsification at each decade boundary: 48/49 vs. 50/51 (OR, 0.956; 95% CI, 0.926–0.986), 58/59 vs. 60/61 (OR, 0.935; 95% CI, 0.909–0.961), and 68/69 vs. 70/71 (OR, 0.903; 95% CI, 0.879–0.927; all P < 0.001). No mid-decade phacoemulsification comparisons were significant. The odds of undergoing MIGS were lower at 48/49 vs. 50/51 (OR, 0.876; 95% CI, 0.814–0.940); no decade-boundary differences were observed for GDI or keratoplasty procedures. Conclusions Consistent with left-digit bias, surgical frequency for phacoemulsification increased at decade transitions. Clinicians should consider the potential influence of age perception in surgical decision-making.