JMIR Publications

ABSTRACT

Background:

Much attention has been drawn to patient portals, which are considered as an important tool for health providers to facilitate patient engagement. However, little is known about whether the intensive use of patient portals contributes to improved management of patients’ health, within the context of their confidence in acquiring health information and exercising self-care. There is a lack of randomized trials with these outcomes measured both pre- and post-adoption of patient portals.

Objective:

The objective of this study was to examine the causal relationship between the usage of patient portals and patients’ self-efficacy towards obtaining health information and taking care of themselves.

Methods:

This study was a secondary data analysis that used a national survey, the National Cancer Institute’s HINTS 5 Cycle 1 data. Patient portal usage frequency was used to define the treatment. Survey items measuring self-efficacy on a Likert-type scale were selected as the main outcomes, including patients’ confidence in 1) getting health information and 2) taking care of their own health. To establish causality using survey data, we adopted the instrumental variables method. We further proposed a novel testing framework that employs conditional independent tests to identify the direction of causal relationship in a directed acyclic graph with the presence of high-dimensional confounders. The average causal effect was measured using two-stage least squares regression.

Results:

We showed that frequently using patient portals improves patients’ confidence in getting health information. The estimand of the weighted average causal effect is 0.14, with a 95% Confidence Interval (0.06, 0.23), P < .001. It means that increasing the portal usage intensity, for instance, from 1-2 times to 3-5 times per year, the expected average increase in confidence level measured on a Likert-type scale is 0.14. However, we cannot conclude a causal effect of using patient portals on patients’ confidence in exercising self-care.

Conclusions:

The results advocate patient portals and promote the need to provide better support and education to patients. The proposed statistical method exploits the potential of national survey data for causal inference studies.