Single-patient multicrossover (n-of-1) trials supported by mobile health applications may not improve pain interference compared with usual care for patients with chronic musculoskeletal pain, according to a randomized clinical trial published in JAMA Internal Medicine.
In this study, 215 patients with chronic musculoskeletal pain for ≥6 months were enrolled between 2014 and 2016 and followed for ≤1 year by a total of 48 clinicians across northern California. Clinician-patient dyads selected therapies and treatment parameters for patients receiving an intervention (n=108) in an n-of-1 trial — a design that allows switching among ≥2 treatment regimens — from the following 8 options: acetaminophen, any nonsteroidal anti-inflammatory drug, acetaminophen/codeine, acetaminophen/hydrocodone, acetaminophen/oxycodone, tramadol, complementary/alternative treatments (eg, massage, meditation, or physical exercise), or current ongoing therapy (or no therapy). A mobile health application reminded patients to take their treatment and answer daily questions on pain and treatment-related adverse effects. Patients in a control group (n=107) were required to visit the clinic for a baseline assessment after which they received usual care.
The study’s primary outcome was change in the 8-item short-form PROMIS (Patient-Reported Outcomes Measurement Information System) pain-related interference scale from time of enrollment to the 6-month follow-up. Secondary outcomes were analgesic adherence, patient-reported pain intensity, overall health, trust in clinician, medication-related shared decision making, satisfaction with care, and participant engagement and experience of the n-of-1 group only.
In the intention-to-treat analysis, pain interference was found to be reduced in the overall cohort at 6 months and was comparable between the control and intervention groups (-1.36 points; 95% CI, -2.91 to 0.19 points; P =.09). Patients in the n-of-1 trials were found to be more likely to report an improvement ≥5 points on the PROMIS scale at follow-up compared with the control group (34% vs 22%, respectively; P =.05). Medication-related shared decision-making scores were higher in patients in the n-of-1/intervention vs control group at 6 months (between-group difference, 11.9 points; 95% CI, 2.6-21.2 points; P =.01).
Limitations of the study include the inability to blind patients to the intervention, the inclusion of patients from a single region of the United States, and the relatively small number of participants in each arm.
“N-of-1 trials are a potentially appealing vehicle for delivering precision medicine in office practice,” concluded the study authors.
Kravitz RL, Schmid CH, Marois M, et al. Effect of mobile device-supported single-patient multi-crossover trials on treatment of chronic musculoskeletal pain: a randomized clinical trial. JAMA Intern Med. 2018;178:1368-1377.