Clinical course of patients with plantar heel pain excluded from the FIX-Heel trial

Background Individuals with plantar heel pain (PHP) are often excluded from randomised clinical trials (RCTs) despite having care-seeking behaviour and symptoms consistent with PHP. This study aimed to describe their clinical course over 12 months after not being included in the FIX-Heel Trial. Methods We conducted a prospective cohort study of individuals with PHP who did not meet one or more of the inclusion criteria: 1) pain on palpation at the medial calcaneal tubercle, 2) plantar fascia thickness >4.0 mm, or 3) pain >30 mm on a 100-mm visual analogue scale. Individuals completed the Foot Health Status Questionnaire (FHSQ) and care-seeking behaviour at baseline and after 4, 12, 26, and 52 weeks. Results We included 28 individuals who were primarily not included in the trial due to their plantar fascia thickness (86%). Significant improvements were observed in FHSQ Pain and Function scores at 12 weeks compared to baseline (mean difference 9.0 (95%CI: 1.5;16.5, P=0.019) and 7.7 (95%CI: 0.3;15.2, P=0.043), respectively), with continued improvement at 26 and 52 weeks. Less than half received treatment at any time point. Conclusion Despite limited care, individuals not included in an RCT experienced clinically meaningful long-term improvement. These findings shed light on the clinical course of individuals excluded from trials.