Secondhand Smoke Respiratory Health Study

Maximum oxygen consumption (Max VO2) as determined by a symptom-limited progressively increasing cycle exercise test to determine the maximum work (watts) and oxygen uptake (VO2) achieved. The protocol consisted of 3-min rest, 1-min unloaded (freewheeling) cycling at 60 rpm, followed by increasing work rate of 20-30 Watts each 2 minutes to a maximum tolerated, and 5-min of recovery. Twelve lead ECGs were monitored continuously and were recorded along with BP every 2 min. Oxyhemoglobin saturation (O2sat) determined by pulse oximetry was recorded continuously.

After 30 minutes period of rest, the subject will perform exercise at increasing work rates corresponding to 20%, 40%, 60%, and 80% of the maximum oxygen uptake attained in the first exercise with 2 minutes at each stage. Inspiratory capacity will be measured 2 to 3 times at each work rate while recording tidal flow-volume loops to assess for evidence of airflow limitation during exercise. Air flow limitation will be determined by calculating the percent overlap of tidal breathing over expiratory portion of maximum flow.

After 30 minutes period of rest, the subject will perform exercise at increasing work rates corresponding to 20%, 40%, 60%, and 80% of the maximum oxygen uptake attained in the first exercise with 2 minutes at each stage. Inspiratory capacity will be measured 2 to 3 times at each work rate while recording tidal flow-volume loops to assess for evidence of airflow limitation during exercise. Dynamic hyperinflation will be measured by changes in examining end-expiratory lung volume at each stage.

The SF-12 is a 12-item questionnaire used to assess generic health outcomes from the patient's perspective. The SF-12 consists of a subset of 12 items from the SF-36® Health Survey (SF-36) and measures two composite outcomes assessing mental health composite score (MCS) and physical health composite scores (PCS). The PCS & MCS are computed using the scores of twelve questions and range from 0 to 100, where a zero score indicates the lowest level of health measured by the scales and 100 indicates the highest level of health. The absolute change in item score by group from baseline up to 12 months was used to assess the quality of life/psychosocial impact on the patients with a larger scores indicating a greater degree of change on physical and mental health.

The AQ20 is given to patients to measure HRQOL related to asthma and chronic obstructive pulmonary disease (COPD) . It contains 20 items, with scores ranging from 0 to 20 - high scores indicate poor HRQOL. The absolute change in item score by group from baseline up to 12 months will be reported

The IPAQ measure a participants physical activity by either telephone interview or self-administered methods. IPAQ assesses physical activity undertaken across a comprehensive set of domains including: leisure time physical activity, domestic and gardening (yard) activities, work-related physical activity, and transport-related physical activity. Based on the participant responses, results are categorized into Low, Moderate, or High levels of physical activity. The absolute change in score by group from baseline up to 12 months will be reported

Real world (outside lab) level of physical activity will be measured using an activity monitor (Actigraph) over a period of a week starting the third week during their treatment. The Actigraph is a monitor that allows collection and analysis of daily activity information about subjects in their normal daily living environment, which records both the number of steps and the time interval during which the steps are taken. The change in score by group from baseline up to 12 months will be reported

The association between respiratory abnormalities and HRQOL outcomes at 12 months will be determined using pearson/spearman correlation. The aim is to show that at least 8%-10% of the variation in level of physical activity or score on our survey tools are explained by the observed lung function abnormalities and cabin SHS exposure (a correlation coefficient of at least 0.28). Correlation coefficients range from + 1 to -1, with a coefficient of 0=no correlation.