Pulmonary Rehabilitation in Functional Outcomes and Its Relationship With Morbidity and Mortality in Patients With COPD

Background: The pulmonary rehabilitation effects on various outcomes of COPD are well known. However, they may be lost over time due to poor adherence to therapy with absence of regular exercise maintenance in long term, disease progression, comorbidities, falls incidence and higher exacerbations frequency. Currently, the main focus is to make the patient more active and ensure the benefits maintenance. However, few studies have been concerned with the aim of to investigate the long-term effect of this intervention and the relationship of the change promoted in important outcomes of the disease with its morbidity and mortality.

Design: Non-controlled clinical trial, prospective and longitudinal. Setting: Outpatient pulmonary rehabilitation program in Florianopolis, Brazil

Subjects: Patients with COPD (GOLD II-IV).

Interventions: Pulmonary rehabilitation program (PRP) based on physical training, conducted over 24 sessions supervised, three times a week, including aerobic training in treadmill and resistance training for upper and lower limbs.

Main measures: Before, post-PRP, 6 months post-PRP and 12 months post-PRP will be measured Spirometry or Total Body Plethysmography, Triaxial Accelerometry by Dynaport Activity Monitor, Glittre ADL-Test to evaluated functional capacity and functional performance, Six-Minute Walk Test distance on tracks of 20 and 30 meters, muscle oxygenation variables by NIRS PortaLite®, force platform NeuroCom® SMART Equitest®, Timed Up and Go Test, Berg Balance Scale, Activities-specific Balance Confidence, Falls Efficacy Scale - International - Brasil, London Chest Activity of Daily Living score, Modified Medical Research Council score, Saint George Respiratory Questionnaire score, COPD Assessment Test score and Hospital Anxiety and Depression Scale, Behavioural Regulation in Exercise Questionnaire-2, Basic Psychological Needs in Exercise Scale, General self-efficacy scale, COPD self-efficacy scale, Pulmonary Rehabilitation Adapted Index of Self-Efficacy. The death cases and numbers of exacerbations and hospitalizations will be measured by monthly phone calls after PRP.

Assigned Interventions: Pulmonary rehabilitation program (PRP) will be conducted according to the American Thoracic Society/European Respiratory Society (ATS/ERS) guidelines. Physical training will be conducted over 24 sessions supervised, three times a week. The program will include aerobic training in treadmill (with 30 min load determined by the dyspnea sensation - 4 to 6 on the modified Borg scale) and resistance training for upper limbs with free weights or elastic bands (movements performed based on the proprioceptive neuromuscular facilitation diagonals, performed in two series, lasting two minutes each) and lower limbs (quadriceps and triceps sural) with free weights and/or in the bodybuilding station. All the muscle exercised and the breathing accessory muscles will be stretched for 30s each. Eleven 30-minute educational sessions will be delivered addressing topics related to disease self-management.

The death cases and numbers of exacerbations and hospitalizations will be measured by monthly phone calls after PRP.

Before PRP, post-PRP, 6 months post-PRP and 12 months post-PRP will be evaluated:

Pulmonary function test: Spirometry (EasyOne, NDD) or Total Body Plethysmography (Eric Jaeger, Germany) will be performed in accordance with ATS/ERS standards in order to provide the level of pulmonary obstruction and severity of disease. The predicted values will be calculated with the equations derived from Brazilian population.

Triaxial Accelerometry by Dynaport Activity Monitor: In order to evaluate the physical activity in daily life (PADL), it will be used DynaPort Activity Monitor (McRoberts BV®, Netherlands). Monitoring took place on four consecutive days lasting 12 hours from awakening. Data processing and analysis will be performed with the Dyrector software (McRoberts BV®).

Glittre-ADL Test (TGlittre): The patients will be instructed to complete the circuit described by Skumlien et al. In one day, the patients will perform two Glittre-ADL Tests with the orientation of performing the test in the shortest possible time. On the other day, two tests will also be performed, however, the patients will be instructed to perform the circuit at his usual speed (TGlittre-Perf). The order of execution of TGlittre and TGlittre-Perf will be randomized previously.

Six minute walk test (6MWT): The patients will be instructed to walk in order to perform the largest distance during six minutes. The walking speed will be selected by the patient, according to the guidelines of the ATS. Two 6MWTs will be conducted on tracks of 20 and 30 meters, in different days, with execution order randomized previously.

Peripheral muscle oxygenation: The patients will use a near-infrared spectroscopy device (NIRS PortaLite®, Artinis Medical Systems) on the vastus lateralis muscle of the dominant lower limb during TGlittre, TGlittre-Perf and 6MWT. The positioning will follow the SENIAM Project (Surface ElectroMyoGraphy for the Non-Invasive Assessment of Muscles) recommendations. The analyzed variables will be oxyhemoglobin, deoxyhemoglobin, total hemoglobin and tissue saturation index.

Postural control: The patients will perform five protocols randomized previously on force platform NeuroCom® SMART Equitest® (Sensory Organization Test, Adaptation Control Test, Motor Control Test, Limits of Stability, Rhythmic Weight Shift e Weight Bearing Squat). Besides, they will perform two Timed Up and Go Test in the shortest possible time and Berg Balance Scale, composed of 14 specific items with different tasks. The Activities-specific Balance Confidence and Falls Efficacy Scale - International - Brasil, both composed for 16 items related to ADL confidence and self-efficacy for falls, respectively, also will be performed. The postural control assessment will be randomized previously.

London Chest Activity of Daily Living scale: Patients will be asked about their perception of limitation in activities of daily living, using the London Chest Activity of Daily Living scale. It consists of 15 items with scores from 0 to 5, with the total score ranging from 0 to 75 points. The higher the score is, the greater the ADL limitation.

Modified Medical Research Council scale: Patients will be asked about their perception of dyspnea, using the modified Medical Research Council scale. The scale range is from 0 to 5, being that higher values correspond to worse dyspnea.

Saint George Respiratory Questionnaire: Patients will be asked about their perception of health-related quality of life, using the Saint George Respiratory Questionnaire. The SGRQ score ranges from 0 to 100% (total and three domains: symptoms, activity and impact), being that higher values correspond to worse quality of life.

COPD Assessment Test: Patients will be asked about the perception of the impact of COPD (cough, sputum, dyspnea, and chest tightness) on health status, using COPD Assessment Test. The total score varies from 0 to 40 and higher scores indicate greater impact of the disease on the health status of these patients.

Hospital Anxiety and Depression Scale: The Hospital Anxiety and Depression Scale will be applied to evaluated symptoms of anxiety and depression. It has two subscales: anxiety and depression. Each subscale generates a final score ranging from 0 to 21 points. Higher scores to more symptoms.

Behavioural Regulation in Exercise Questionnaire-2 (BREQ-2): the questionnaire assesses motivation to exercise. It consists of 19 Likert-based items that measure motivation to exercise. The self-determination index (SDI) will be scored. It ranges between -24 (lowest SDI) to 20 (highest SDI). The higher the SDI score, the greater the motivation to exercise.

Basic Psychological Needs in Exercise Scale: it assesses the patient´s perception regarding the supply of basic psychological needs and with the exercise. It is composed by 12 items that are divided into three domains: autonomy (four items), competence (four items), and relatedness (four items). Each item varies from from 1 ("totally disagree") to 5 ("very strongly agree"). The domains scores varies from 4 to 20. The higher the score, the greater the fulfillment of basic psychological needs.

COPD self-efficacy scale: the scales will be used to assess disease-specific self-efficacy. It assesses an individual's confidence in managing dyspnoea or other breathing-related issues. It is a Likert-based scale, consisting of 34 items divided into the following 5 subscales: negative affect (12 items), intense emotional arousal (8 items), physical exertion (5 items), weather or environment (6 items), behavioural risk factors (3 items). The total score ranges from 34 to 170 points. It can be also presented by a mean of the 34 items (sum of the items divided for 34). The higher the score, the greater the self-efficacy for both scales.

General self-efficacy scale: the scales will be used to assess general self-efficacy. It is a 10-item Likert-based scale, whose score varies from 10 to 40. The higher the score, the greater the self-efficacy.

Pulmonary Rehabilitation Adapted Index of Self-Efficacy: the scale will assess self-efficacy in the context of PR. It is composed by 10 items from the General Self-efficacy Scale and 5 items specific to challenges faced by patients attending a pulmonary rehabilitation program. Each item is scored from 1 to 4, with 4 being the highest level of perceived self-efficacy and 1 being considered the lowest level. The score range comprises a score of 15 to 60, with higher scores indicating high levels of self-efficacy.

Eligibility Criteria:
Inclusion Criteria:

* Clinical diagnosis of COPD confirmed by spirometry (COPD GOLD stages II, III and IV);
* Clinical stability in the past four weeks.

Exclusion Criteria:

* Hospital admission in the past 12 weeks;
* Any other disease or health condition that could compromise the test´s execution or physical training;
* Participation in pulmonary rehabilitation program completed in the last six months;
* Current smoking or its cessation in less than six months;
* Interruption of pulmonary rehabilitation program for any reason;
* Any change in symptoms during the study protocol assessments.