Current literature lacks solid evidence on the improvement of heart rate variability (HRV) after exercise training in patients with COPD.

OBJECTIVES: We aimed to investigate changes in HRV after two exercise training programs in patients with COPD and to investigate the determinants of these eventual changes.

METHODS: Forty patients with COPD (FEV(1) 39±13%pred) were randomized into high (n=20) or low (n=20) intensity exercise training (3-month duration), and had their HRV assessed by the head-up tilt test before and after either protocols. Baseline spirometry, level of daily physical activity, exercise capacity, body composition, functional status, health-related quality of life and muscle force were also assessed to investigate the determinants of improvement in HRV after the training program.

RESULTS: There was a significant improvement in HRV only after the high-intensity protocol (pre versus post; SDNN 29±15ms versus 36±19ms; rMSSD 22±14ms versus 28±22ms; p<0.05 for both). Higher values of biceps brachialis strength, time spent walking in daily life and SDNN at baseline were determinants of improvement in HRV after the training program.

CONCLUSIONS: High-intensity exercise training improves HRV at rest and during orthostatic stimulus in patients with COPD. Better baseline total HRV, muscle force and daily physical activity level are predictors of HRV improvements after the training program.

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Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death among US adults and is projected to be the third by 2020. In anticipation of the increasing burden imposed on healthcare systems and payers by patients with COPD, a means of identifying COPD patients who incur higher healthcare utilization and costs is needed.

METHODS: This retrospective, cross-sectional analysis of US managed care administrative claims data describes a practical way to identify COPD patients. We analyze 7.79 million members for potential inclusion in the COPD cohort, who were continuously eligible during a 1-year study period. A younger commercial population (7.7 million) is compared with an older Medicare population (0.115 million). We outline a novel approach to stratifying COPD patients using "complexity" of illness, based on occurrence of claims for given comorbid conditions. Additionally, a unique algorithm was developed to identify and stratify COPD exacerbations using claims data.

RESULTS: A total of 42,565 commercial (median age 56 years; 51.4% female) and 8507 Medicare patients (median 75 years; 53.1% female) were identified as having COPD. Important differences were observed in comorbidities between the younger commercial versus the older Medicare population. Stratifying by complexity, 45.0%, 33.6%, and 21.4% of commercial patients and 36.6%, 35.8%, and 27.6% of older patients were low, moderate, and high, respectively. A higher proportion of patients with high complexity disease experienced multiple ([greater than or equal to]2) exacerbations (61.7% commercial; 49.0% Medicare) than patients with moderate- (56.9%; 41.6%), or low complexity disease (33.4%; 20.5%). Utilization of healthcare services also increased with an increase in complexity.

CONCLUSION: In patients with COPD identified from Medicare or commercial claims data, there is a relationship between complexity as determined by pulmonary and non-pulmonary comorbid conditions and the prevalence of exacerbations and utilization of healthcare services. Identification of COPD patients at highest risk of exacerbations using complexity stratification may facilitate improved disease management by targeting those most in need of treatment.

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The 5-item, caregiver-completed Test for Respiratory and Asthma Control in Kids (TRACK) was developed and validated primarily in asthma-specialist practices to monitor respiratory control in preschool-aged children. This longitudinal study in children treated by pediatricians evaluated the responsiveness of TRACK to changes in respiratory- and asthma-control status over time and further assessed TRACK's reliability and validity.

Patients and Methods: Caregivers of children younger than 5 years with symptoms consistent with asthma within the past year (N = 438) completed TRACK at 2 clinic visits separated by 4 to 6 weeks. Physicians were blinded to caregiver assessment, completed a guidelines-based respiratory-control survey at both visits, and were asked whether the visit resulted in a change in therapy. Responsiveness of TRACK to change in respiratory-control status over time was evaluated; reliability and discriminant validity were assessed.

Results: Mean changes in TRACK scores from the initial to follow-up visits differed in the expected direction in subsets of children whose clinical status improved, remained unchanged, or worsened based on physicians' and caregivers' assessments (P < .001). Mean TRACK scores also differed significantly (P < .001) across patient subsets, with lower scores (indicating poorer control) in children classified as very poorly controlled, in those who required a step-up in therapy, and in those who had 4 or more episodes or attacks of wheezing, coughing, or shortness of breath per week in the past 3 months.

Conclusions: The present study extends the validity and reliability of the TRACK by demonstrating its responsiveness to change in respiratory-control status over time in preschool-aged children with symptoms consistent with asthma.

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