Background: A home based tele-monitoring system was developed to assess the effects of heat stress (days > 25°C) on clinical and functional status in patients with chronic obstructive pulmonary disease (COPD).
Methods: Sixty-two COPD patients (GOLD II-IV) were randomized into a tele-monitoring Group (TG, N = 32) or Control Group (CG, N = 30). Tele-monitoring included 1) daily clinical status (COPD Assessment Test-CAT), 2) daily lung function and 3) weekly 6-minute walk test (6MWT). Duration of monitoring lasted a total of nine months (9 M).
Results: From June 1st-August 31st 2012, 32 days with heat stress (29.0 ± 2.5°C) were recorded and matched with 32 thermal comfort days (21.0 ± 2.9°C). During heat stress, the TG showed a significant reduction in lung function and exercise capacity (FEV1% predicted: 51.1 ± 7.2 vs. 57.7 ± 5.0%; P <0.001 and 6MWT performance: 452 ± 85 vs. 600 ± 76 steps; P <0.001) and increase in CAT scores (19.2 ± 7.9 vs. 16.2 ± 7.2; P <0.001).Over summer, significantly fewer TG patients suffered exacerbation of COPD compared to CG patients (3 vs. 14; P = 0.006). Over entire 9 M follow-up, the TG group had fewer exacerbations compared to CG (7 vs. 22; P = 0.012), shorter cumulative hospital stay (34 vs. 97 days) and 43% fewer specialist consultations (24. vs. 42; P = 0.04).
Conclusion: Heat stress affects clinical and functional status in COPD. Tele-monitoring reduces exacerbation frequency and health care utilization during heat stress and other periods of the year.
Trial registration drks-id: DRK00000705.