The number of knee arthroplasty procedures performed in the United States has increased annually, accompanied by rises in health care resource use and costs [1]. Risk-sharing and bundled payment plans have been implemented with the goal of improving care and controlling costs through the sharing of financial responsibility for a 90-day joint replacement episode-of-care (EOC) [2]. Approximately 36% of the EOC cost has been attributed to postdischarge services [3]. In-person outpatient physiotherapy (PT) has been the standard of care (SoC) postoperatively but is associated with significant cost and may be overused following uncomplicated knee arthroplasty [4]. Telerehabilitation and mobile health delivery of PT has gained popularity in recent years [5]. The aim of this study was to compare costs of a smartphone-based care management platform (sbCMP) with traditional care in adult patients undergoing knee arthroplasty.

Preoperative patient characteristics as well as baseline and postsurgical clinical outcomes were similar between the two groups [6]. The estimated costs associated with health care resources are presented in Table 1. The number of events was lower in the treatment group in each category except for non-SoC physician office visits. Patients using the sbCMP had significantly fewer ED visits and readmissions. The average cost per patient was approximately US $732 lower in the treatment group after including the cost of the sbCMP. The reduction in the number of in-person PT visits accounted for the bulk of the potential savings in the cohort, with costs approximately US $400 less in the treatment group. The average number of PT visits in the control and sbCMP groups were 9.75 (SD 3.98) and 5.40 (SD 5.51), respectively. Considering only noncrossovers, average costs were further reduced to approximately US $186 per patient through 90 days (Table 2). Sensitivity analyses demonstrated cost savings across all scenarios (Multimedia Appendix 1).

This analysis demonstrated cost savings for patients using the sbCMP for self-directed rehabilitation following primary knee arthroplasty. Most savings were derived from the reduction in PT, the most common resource used. Cost savings were also achieved with the sbCMP for all health care resources except physician office visits. It is possible that this increase in office visits is the result of improved communication between patients and their care team via real-time messaging. This may have prompted additional unexpected office visits for postoperative concerns, which may have prevented more costly ED visits or readmissions. Alternately, this could be due to a patient need for feedback and assurance not received during in-person PT.

To our knowledge, this is the first cost comparison analysis of this care management platform compared with traditional care. There are few studies of other telerehabilitation programs compared with traditional care in this context. One study reported reduced outpatient PT costs with increased use of web-based PT [9] and another reported overall EOC cost savings with telerehabilitation and acknowledged improved outcomes, without attributing costs to the type of event [10].

A key limitation of this analysis is the uncertainty regarding the generalizability of the list price for the sbCMP used in the analysis. Additionally, the cost data may not be generalizable. Postacute care use was not accounted for given it is not expected to differ between treatment modalities.

In conclusion, the sbCMP has a potential for robust cost savings without negatively impacting postsurgical outcomes in patients undergoing knee arthroplasty.