Robert P. Murray

Error in smoking measures: effects of intervention on relations of cotinine and carbon monoxide to self-reported smoking. The Lung Health Study Research Group.

OBJECTIVES Sources of measurement error in assessing smoking status are examined. METHODS The Lung Health Study, a randomized trial in 10 clinical centers, includes 3923 participants in a smoking cessation program and 1964 usual care participants. Smoking at first annual follow-up was assessed by salivary cotinine, expired air carbon monoxide, and self-report. Each of these measures is known to contain some error. Sensitivity and specificity were calculated by comparing a biochemical measure with self-report to produce an undifferentiated estimate of error. Classification error rates due to imprecision of the biochemical measures and to the error in self-report were estimated separately. RESULTS For cotinine compared with self-report, the sensitivity was 99.0% and the specificity 91.5%. For carbon monoxide compared with self-report, the sensitivity was 93.7% and the specificity 87.2%. The classification error attributed to self-report, estimated by comparing the results from intervention and control groups, was associated with the responses of 3% and 5% of participants, indicating a small but significant bias toward a socially desirable response. CONCLUSIONS In absolute terms in these data, both types of error were small.

Social support for smoking cessation and abstinence: The lung health study☆

This article evaluates the relationship of social support to smoking cessation and continued abstinence of 3923 men and women with mild to moderate airway obstruction in the Lung Health Study. At both the end of a 12-week group program and after 1 year, men but not women who were supported in quitting were more likely to be successful. Married status facilitated quitting but was less strongly related to long-term abstinence. Participants supported by an ex-smoker who had attended the group program with them were very likely not smoking after 1 year (men, 74.7%; women, 72.4%). Participants supported by a smoker were less than half as likely to have achieved abstinence after 1 year but still had cessation rates greater than 30%. The nature of these relationships has implications for the distinction between women and men in studies of social support and for intervention strategies. Support people should be included in cessation intervention programs. Spouse involvement, however, is more evidently useful for men than for women.

Lifestyle intervention on diet and exercise reduced excessive gestational weight gain in pregnant women under a randomised controlled trial

Please cite this paper as: Hui A, Back L, Ludwig S, Gardiner P, Sevenhuysen G, Dean H, Sellers E, McGavock J, Morris M, Bruce S, Murray R, Shen G. Lifestyle intervention on diet and exercise reduced excessive gestational weight gain in pregnant women under a randomised controlled trial. BJOG 2012;119:70–77.

A structural equation model of the effect of poverty and unemployment on alcohol abuse.

The short- and long-term effects of poverty and unemployment on alcohol abuse are investigated using structural equation modelling (SEM) to better understand the observed conflicting relationships among them. We studied 795 community residents who provided complete data in both 1989 and 1991 in the Winnipeg Health and Drinking Survey (WHDS), with equal representation of males and females. Results indicate that (a) increased poverty causes increased alcohol use and alcohol problems, and (b) recent unemployment decreases alcohol use while longer unemployment increases it. It is concluded that the effect of unemployment on alcohol abuse changes direction with time and, thus, both cross-sectional and longitudinal data are required to assess any meaningful relationship between them.

Effects of Multiple Attempts to Quit Smoking and Relapses to Smoking on Pulmonary Function

The effect of intermittent smoking on pulmonary function was assessed among participants in the Lung Health Study, 5887 adult smokers with evidence of early chronic obstructive pulmonary disease (COPD), followed up for 5 years. The mean annual rate of loss in FEV1% of predicted after year 1 was smallest for those who quit at some point during the first year of the study and stayed quit (-0.33%/year, +/-0.05%), intermediate for those who smoked intermittently during the study (-0.58%/year, +/-0.05%) and greatest for those who continued to smoke throughout the study (-1.18%/year, +/-0.03%). Surprisingly, those who made several attempts to quit smoking had less loss of lung function at comparable cumulative doses of cigarettes than those who continued to smoke. Quitting smoking for an interval followed by relapse to smoking appeared to provide a measurable and lasting benefit in comparison to continuous smoking. In this early COPD population, not only quitting smoking but attempts to quit smoking can prevent some loss of lung function. These results provide some encouragement to exsmokers who relapse on their way to complete cessation.

Smoking reduction and the rate of decline in FEV1: results from the Lung Health Study

Previous findings from the Lung Health Study have shown that smoking cessation and sustained abstinence substantially reduce the rate of decline in forced expiratory volume (FEV1) among smokers with early chronic obstructive pulmonary disease (COPD) when compared with continuing smoking. Intermittent quitters demonstrated rates of FEV1 decline intermediate between those of sustained quitters and continuing smokers. In this study, data from 1,980 participants were analysed from 10 centres of the Lung Health Study in the USA and Canada. All participants were smokers with mild-to-moderate COPD who were unable to quit smoking at any time during the 1st yr of the study. No linear relationship was found between reduction in cigarettes per day and changes in FEV1 during the 1st yr of the study. However, examination of the data revealed that this relationship was nonlinear. Further analysis found that smokers who reduced their cigarettes per day to very low amounts had smaller declines in FEV1 than those who did not. Reduction in cigarettes per day was associated with only minimal changes in the presence of chronic respiratory symptoms. In conclusion, compensatory changes in smoking behaviour may account for the limited and unpredictable impact of smoking reduction on lung function decline and symptom prevalence when compared with smoking cessation.

Community-based Exercise and Dietary Intervention During Pregnancy:A Pilot Study

ABSTRACT OBJECTIVE To determine the feasibility of implementing a communitybased exercise/dietary intervention program targeted at socioeconomically deprived pregnant women living in an urban core in an attempt to reduce risks of obesity and diabetes. METHODS Fifty-two participants were enrolled and randomized into additional intervention (AI) and standard care (SC) groups. Participants in the AI group undertook group and homebased exercises during pregnancy and received computerassisted Food Choice Map dietary interviews and counselling. Participants in the SC group received an information package on diet and activity for a healthy pregnancy. RESULTS Forty-five participants completed the study (SC group, n=21, AI group, n=24). No adverse effects of exercise were observed during the study. Physical activity levels in the AI group were greater than those in the SC group (p CONCLUSIONS The results of this pilot study demonstrated the feasibility of the lifestyle intervention during pregnancy and its potential to improve pregnancy outcomes in urban communities.

Weight Gain as a Function of Smoking Cessation and 2-Mg Nicotine Gum Use Among Middle-Aged Smokers With Mild Lung Impairment in the First 2 Years of the Lung Health Study

The extent and predictors of weight change were assessed among sustained nonsmoking special intervention participants in the Lung Health Study. The intervention included a 12-session group program and 2-mg nicotine gum. At 12 months, female sustained quitters (SQs; n = 248) had gained a mean of 8.4% (5.3 kg) of their baseline weight, whereas male SQs (n = 443) had gained 6.7% (5.5 kg). By 24 months, female SQs had gained 9.8% of their baseline weight compared with 6.9% for men. Nicotine gum usage delayed a portion of the weight gain. Multiple regression analysis showed that weight gain at 12 months was associated with a higher baseline salivary cotinine level, a lower baseline body mass index, drinking less alcohol per week, and a lower cotinine level at 12 months (indicating less or no nicotine gum use). We conclude that moderate weight gain is a long-term consequence of smoking cessation--a portion of which can be delayed with 2-mg nicotine gum.

An Empirical Study of Empowerment in the Workplace

Empowerment in the workplace was developed and practiced in the 1950s and 1960s. Recent forces in the business community, such as globalization, skilled staff shortages, and the need for innovation and productivity have added momentum to the search for ways to survive. Despite limited empirical evidence, empowerment has been advocated as a promising solution. This study evaluates the effect of a controlled introduction of empowerment, with reference to power, managerial functions, leadership styles, and employee motivation. Data from 81 employees who were formally empowered were compared with 90 individuals in a control group. Results provided minimal support for the positive influence of empowerment. The disruptive nature of corporate downsizing that occurred during the introduction of empowerment may have nullified its effect.

Menthol Cigarettes and Health Risks in Lung Health Study Data

Whether menthol cigarettes confer a higher risk of death than plain cigarettes is not known. The Lung Health Study (LHS) enrolled 5,887 adult smokers in a clinical trial of smoking cessation and ipratropium in the prevention of chronic obstructive pulmonary disease. LHS participants have been subjected to surveillance for mortality from all causes for 14 years. We examined these data for differences between self-reported smokers of menthol cigarettes versus plain cigarettes. Using proportional hazards regression methods, we found no differences in hazard ratios for coronary heart disease, cardiovascular disease, lung cancer, or death from any cause. Contrary to expectations about nicotine dependence, we found that users of menthol cigarettes had smoked fewer pack-years at baseline. We found no difference in success at smoking cessation with or without menthol. We conclude that our data contain no evidence that mentholation of cigarettes increases the hazards of smoking.