From office to digital primary care services: analysing income-related inequalities in utilization.

The use of digital technologies to deliver primary health care has increased over the past decade. While some technologies have been shown to be medically effective and efficient, the effects of digital primary care on the policy goal of equality in the use of such types of care have not been studied using large register data. The aim of this study was to analyse how digital contacts differ from officebased visits by income as an indicator of socioeconomic status. Specifically, we estimated differences in primary care utilization across income, factors of contribution to these inequalities, and applied a needs-based standardisation of utilization to estimate differences in equity.We used a purposively built consultation level dataset with 726 000 Swedish adult patients diagnosed with an infection, including clinical and sociodemographic variables. Applying concentration indexes (CI) and graphical illustrations we measured how the two types of services are distributed relative to income. We estimated how much of the inequalities were attributed to different sociodemographic factors by decomposing the concentration indexes. Standardised utilization for sex, age and comorbidity allowed for the estimation of horizontal inequity indexes for both types of services.Utilization by the two types of care showed large income inequalities. Office-based visits were propoor (CI -0.116), meaning lowincome patients utilized relatively more of these services, while digital contacts were prorich (CI 0.205). However, within the patient group who had at least one digital contact, the utilization was also propoor (CI -0,101), although these patients had higher incomes on average. The standardised utilization showed a smaller prorich digital utilization (CI 0.143), although large differences remained. Decomposing the concentration indexes showed that education level and being born in Sweden were strong attributes of prorich digital service utilization.The prorich utilization effects of digital primary care may risk undermining the policy goals of access and utilization to services regardless of socioeconomic status. As digital health technologies continue to expand, policy makers need to be aware of the risk.