Effect of adherence to home spirometry on bronchiolitis obliterans and graft survival after lung transplantation.

Background: Patient-controlled home spirometry (HS) after lung transplantation has been shown to be valid and reliable to detect the presence of graft infection and rejection at its earliest onset. Effects of nonadherence to HS on detection of the bronchiolitis obliterans syndrome (BOS) and on graft survival are unknown.

Methods: A 7-year prospective cohort study assessed nonadherence longitudinally using electronic spirometry for 24 months. During follow-up, BOS, retransplantation, and survival were stratified by adherence groups.

Results: Electronic monitoring of 226 patients confirmed that 123,487 measures were performed. Period prevalence was 0.76 measures per patient day and decreased significantly over time (P<0.0001). During follow-up, BOS was developed in 32% of patients; 5% received a second transplant, and mortality rate was 19%. Kaplan-Meier event-free analysis showed decreased freedom from BOS time in nonadherers (30%) compared with good (43%) or moderate adherers (19%) (log rank 6.008; P<0.014) and a tendency toward lower retransplantation rates (log rank 3.14; P<0.07). Mantel Cox regression revealed no impact of adherence on patient survival.

Conclusions: This was the first study assessing nonadherence to HS based on electronic monitoring in relation to long-term outcome after lung transplantation. Nonadherers showed decreased freedom from BOS in the largest sample to date, but did not impact survival.