A new study from Hinge Health, Inc., a supplier of online, digital patient therapies collected medical claims data and compared it to patients who had been treated with their products and found, no surprise, that their digital therapy services reduced the rate of surgical intervention for knee or hip osteoarthritis (OA).
We’re publishing the details of this study despite its obvious bias, because the study methodology, as designed by the five member research team (two of whom are Hinge Health employees, three of which own equity in Hinge Health) with strong pedigrees from Department of Radiology, University of Washington (LSG), Seattle, WA; Department of Surgery and Perioperative Care, Dell Medical School, The University of Texas at Austin (KMK), Austin, TX; Weitzman Institute (GW), Middletown, CT., because, we think, the study did develop interesting new clinical insights for large joint osteoarthritic care.
The five study authors (Louie Lu, Ph.D., Laura S. Gold, Ph.D., Karl M. Koenig, M.D., M.S., Jonathan H. Lee, M.D., M.B.A. and Grace Wang, Ph.D., M.P.H.) published the results of their study, titled “Digital Musculoskeletal Program Is Associated With Decreased Joint Replacement Rates” in The American Journal of Managed Care October 2023.
What Is ‘Digital Health’?
“Digital health” refers to a smart phone or computer-based software program which motivates and guides patients through a personalized program of exercise therapy, education and coaching.
Many employers (approximately 66 in the U.S.) provide this as a health benefit for employees and dependents in order to, they hope, improve their employee’s ability to manage chronic knee or hip pain non-interventionally. The software presents patients with 3 to 8 different stretching, strengthening, balance, and mobility exercises via animations and videos. It also provides wearable motion sensors (InvenSense MPU-6050; TDK Corporation) that gives feedback through the app about range of movement and repetitions. Finally, after exercises, patients using the app receive educational resources and support from certified health coaches.
Study Methodology
Using, presumably, Hinge Health’s list of subscribers to its software program, the study authors identified study participants who had begun using the software app between January 2020 and October 2020. Then, using privacy-preserving linkage tokens provided by Datavant, the researchers located the medical claims records for these subscribers to the Hinge Health software app.
The researchers then assigned appropriate knee or hip ICD-10-CM codes to each subscriber (aka: digital member).
Finally, the two researchers accessed medical claims data from January 2016 and September 2021 for patients coded for knee or hip osteoarthritis.
In total, the researchers were able to access 56,634 knee OA medical claims patients and 20,819 hip OA medical claims patients. From those two large datasets, the researchers culled out 739 knee OA patients and 141 hip OA patients who matched the 77,453 digital patients for age (18-64 years), continuous enrollment in a health plan for at least 12 months and having an index event (enrolling into the software app program or beginning a different treatment program). Patients with cancer, pregnancy, childbirth or an outlier medical costs, were excluded.
The study match was 1:1—digital patients for medical claims data patients.
Study Results and Conclusions
The study authors reported that “adults with osteoarthritis who took part in a digital musculoskeletal program had lower rates of knee and hip arthroplasty at 12 months vs those using traditional care.”
Quoting from the study, “digital members were matched to control group patients with similar demographics, comorbidities, and baseline MSK-related medical care use.” At 12 months after treatment, total knee arthroplasty (TKA) and total hip arthroplasty (THA) rates were then compared.
For the knee osteoarthritis group, the study matched 739 of 56,634 control group patients to 739 digital members. At 12 months, the study found “3.79% of digital members and 14.21% of control group patients had total knee arthroplasty (difference, 10.42%; P < .001).”
For the hip osteoarthritis group, the study matched 141 of 20,819 control group patients to 141 digital members. At 12 months, the study found “16.31% of digital members and 32.62% of control group patients had total hip arthroplasty (difference, 16.31%; P = .001).”
Bottom line, the study authors reported lower rates of both total knee arthroplasty and total hip arthroplasty among digital members when compared to the control group patients who received traditional care. Notably, “73% fewer digital members underwent total knee arthroplasty, and 50% fewer digital members underwent total hip arthroplasty than control group patients at 12 months.”
Inpatient or Outpatient – any Difference?
The study also looked at surgery settings to determine whether the total knee arthroplasty or total hip arthroplasty occurred at an inpatient or outpatient setting.
The authors did this because “projections show that joint replacement surgeries are on the rise and that the surgeries are shifting from inpatient to outpatient settings.”
And the authors found “fewer surgeries in both settings” and that the “decrease was similar for both settings.” This included the observation that “69% fewer inpatient total knee arthroplasty surgeries and 75% fewer outpatient TKA surgeries among digital members vs control group patients.”
The study also discussed the potential impact on cost that digital MSK programs may have. Based on surgery cost estimates, and data from the study, the researchers found that a digital MSK program may be associated with savings of avoided patient costs related to the surgeries.
The study had a number of limitations including the time period of the study. The study period was from 2019 to 2021 which coincided with pandemic shutdowns. The researchers acknowledged that it is “it is plausible that COVID-19 had an effect on the findings” for this reason.
The study’s authors are employed by and own equity in Hinge Health, Inc., which provided the digital musculoskeletal program to participants and funded the research study.
