Two distinct healthcare utilisation trajectories prior to a COPD diagnosis in a multi-ethnic Asian population: a comparison of transient and chronic users.

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) imposes substantial clinical and economic burdens. Early detection can allow for monitoring and timely treatment to slow its progression. Tracking of patient trajectories prior to their diagnosis can inform the timing and targeting of interventions. We aimed to identify pre-diagnosis healthcare utilisation patterns in a COPD cohort and profile the associated subgroups.

METHODS: We conducted a retrospective cohort study of patients with a new inpatient or specialist outpatient clinic (SOC) diagnosis of COPD from 2018 to 2019 in a regional health system in Singapore. Their healthcare utilisation, expenditure and diagnoses from the 3 years prior to diagnosis were extracted. Patients were classified into subgroups with different expenditure and utilisation patterns using Bayesian mixture modelling and compared against a propensity score-matched non-respiratory control group.

RESULTS: 1171 patients with COPD were matched to a control and classified as either chronic (n=688) or transient healthcare users (n=483) prior to a first COPD diagnosis. Chronic users had increasing utilisation over time across all settings, recording multiple SOC visits (median, 25th-75th percentile: 10, 5-20). Transient users had low utilisation throughout, reporting fewer SOC visits than controls (transient: 0, 0-1, control: 2, 0-9). The prevalence of hypertension or hyperlipidaemia was >50% in chronic users, >30% in controls and <30% in transient users.

CONCLUSION: Early detection strategies should focus on case-finding among patients with known risk factors in SOCs for referral to respiratory care and outreach to socially disadvantaged communities to facilitate timely access to healthcare.