Subgroup analysis of telehealthcare for patients with chronic obstructive pulmonary disease: the cluster-randomized Danish Telecare North Trial

PURPOSE: Results from the Danish cluster-randomized trial of telehealthcare to 1,225 patients with chronic obstructive pulmonary disease (COPD), the Danish Telecare North Trial, concluded that the telehealthcare solution was unlikely to be cost-effective, by applying international willingness-to-pay threshold values. The purpose of this article was to assess potential sources of variation across subgroups, which could explain overall cost-effectiveness results or be utilized in future economic studies in telehealthcare research. METHODS: First, the cost-structures and cost-effectiveness across COPD severities were analyzed. Second, five additional subgroup analyses were conducted, focusing on differences in cost-effectiveness across a set of comorbidities, age-groups, genders, resource patterns (resource use in the social care sector prior to randomization), and delivery sites. All subgroups were investigated post hoc. In analyzing cost-effectiveness, two separate linear mixed-effects models with treatment-by-covariate interactions were applied: one for quality-adjusted life-year (QALY) gain and one for total healthcare and social sector costs. Probabilistic sensitivity analysis was used for each subgroup result in order to quantify the uncertainty around the cost-effectiveness results. RESULTS: The study concludes that, across the COPD severities, patients with severe COPD (GOLD 3 classification) are likely to be the most cost-effective group. This is primarily due to lower hospital-admission and primary-care costs. Telehealthcare for patients younger than 60 years is also more likely to be cost-effective than for older COPD patients. Overall, results indicate that existing resource patterns of patients and variations in delivery-site practices might have a strong influence on cost-effectiveness, possibly stronger than the included health or sociodemographic sources of heterogeneity. CONCLUSION: Future research should focus more on sources of heterogeneity found in the implementation context and the way telehealthcare is adopted (eg, by integrating formative evaluation into cost-effectiveness analyses). TRIAL REGISTRATION: Clinicaltrials.gov, NCT01984840.