Phyllis L. Pirie

Validity and Reliability of Short Physical Activity History: Cardia and the Minnesota Heart Health Program

Validity and reliability of a short physical activity history were assessed in two studies. Validity was studied in 2766 women and 2303 men, participants in CARDIA, a biracial study. Ages ranged from 18 to 30 years. The activities performed in the past 12 months by ≥ 50 percent of participants were walking/hiking, nonstrenuous sports, shoveling/lifting during leisure, running/jogging and home maintenance/gardening. Validity was indirectly assessed by studying the relationships of total activity to skinfold thickness, total caloric intake, duration on a self-limited maximal exercise test, and high density lipoprotein cholesterol. Less than perfect correlation are expected since physical activity is not the only factor affecting the validation criteria and since physical activity patterns change over time within each person. Comparing the highest physical activity quartile to the lowest physical activity quartile, mean level of sum of three skinfolds was 10.7 mm less for women (correlation coefficient (r) = -0.15, P < 0.001) and 6.9 mm less for men (r = -0.12, P < 0.001); mean level of caloric intake was 158 kcal morefor women (r = 0.07, P < 0.001) and 875 kcal morefor men (r = 0.21, P < 0.001); mean level of duration on treadmill was 132 seconds more for women (r = 0.36, P < 0.001) and 95 seconds more for women (r = 0.25, P < 0.001); and mean level of high density lipoprotein cholesterol was 4.8 mg/dL more for women (r = 0.13, P < 0.001) and 3.2 mg/dL more for men (r = 0.11, P < 0.001). Reliability was studied in a separate population by comparing questionnaire results in an initial telephone administration with results obtained two weeks later (N = 129). Similar types and amounts of activity were reported in this group as in the group studied for validity. Test-retest correlation coefficients for three summary scores ranged from 0.77 to 0.84, and were at least 0.57 for each of the 13 activity groupings queried. This questionnaire typically takes 5-10 minutes to administer. It yields moderately detailed information about type and amount of usual leisure time physical activity.

An investigation of the cause of the eosinophilia–myalgia syndrome associated with tryptophan use

BACKGROUND The eosinophilia-myalgia syndrome is a newly recognized illness that has been associated with the consumption of tryptophan products. It is not known whether the cause is related to the tryptophan itself or to chemical constituents introduced by the manufacturing process. METHODS To describe the epidemiology of the eosinophilia-myalgia syndrome further and elucidate a possible association with the manufacturing process, we conducted surveillance for the syndrome in Minnesota, a community survey of tryptophan use in Minneapolis-St. Paul, and a case-control study to assess potential risk factors, including the use of tryptophan from different manufacturers. We performed high-performance liquid chromatography on tryptophan samples to identify other chemical constituents. RESULTS The prevalence of tryptophan use increased from 1980 to 1989 and was highest among women. Among the subjects for whom the source of the tryptophan was known, 29 of 30 case patients (97 percent) and 21 of 35 controls (60 percent) had consumed tryptophan manufactured by a single company (odds ratio, 19.3; 95 percent confidence interval, 2.5 to 844.9; P less than 0.001). This company used a fermentation process involving Bacillus amyloliquefaciens to manufacture tryptophan. Analysis of the manufacturing conditions according to the retail lot demonstrated an association between lots used by case patients and the use of reduced quantities of powdered carbon in a purification step (odds ratio, 9.0; 95 percent confidence interval, 1.1 to 84.6; P = 0.014), as well as the use of a new strain of B. amyloliquefaciens (Strain V) (odds ratio, 6.0; 95 percent confidence interval, 0.8 to 51.8; P = 0.04). There was a significant correlation (r = 0.78, P less than 0.001) between the reduced amount of powdered carbon used during manufacturing and the use of the new bacterial strain. High-performance liquid chromatography of this companys tryptophan demonstrated one absorbance peak (peak E) that was present in 9 of the 12 retail lots (75 percent) used by patients and 3 of 11 lots (27 percent) used by controls (odds ratio, 8.0; 95 percent confidence interval, 0.9 to 76.6; P = 0.022). CONCLUSIONS The outbreak of the eosinophilia-myalgia syndrome in 1989 resulted from the ingestion of a chemical constituent that was associated with specific tryptophan-manufacturing conditions at one company. The chemical constituent represented by peak E may contribute to the pathogenesis of the eosinophilia-myalgia syndrome, or it may be a surrogate for another chemical that induces the syndrome.

Recruitment in the Coronary Artery Disease Risk Development in Young Adults (Cardia) study

Coronary Artery Disease Risk Development in Young Adults (CARDIA) is a longitudinal study designed to trace the development of risk factors for coronary heart disease in 5100 individuals 18-30 years old. The study will compare, by cross-sectional and longitudinal analyses, trends and processes involved in risk factor development by sex, race, age, and other sociodemographic characteristics. Participants for the approximately 4 1/2-hour baseline examination were randomly selected and recruited by telephone from census tracts in Minneapolis and Chicago, by telephone exchanges within the Birmingham city limit, and from lists of the Kaiser-Permanente Health Plan membership in Oakland and Berkeley. A major issue was the desirability of sampling approximately equal numbers by age, race, sex, and education as compared with sampling numbers representative of the population base. The recruitment goal of 5100 was achieved on schedule.

Community-wide prevention of cardiovascular disease: Education strategies of the Minnesota Heart Health Program

The Minnesota Heart Health Program (MHHP) is a research and demonstration project of population-wide primary prevention of cardiovascular disease. Study goals are to achieve reductions in cardiovascular disease risk factors and morbidity and mortality in three education communities compared with three reference communities. The program in the first of the three intervention communities, Mankato, has been operating for 3 of the planned 5 years. Early objectives of the program have been achieved based on data obtained from population-based random samples surveyed in education and comparison communities. After 2 years of participation, Mankato was significantly more exposed to activities promoting cardiovascular disease prevention. In this town of 38,000 inhabitants, 190 community leaders were directly involved as program volunteers, 14,103 residents (over 60% of adults) attended a screening education center, 2,094 attended MHHP health education classes, 42 of 65 physicians and 728 other health professionals participated in continuing education programs offered by MHHP, and distribution of printed media averaged 12.2 pieces per household. These combined educational strategies have resulted in widespread awareness of MHHP and participation by the majority of the Mankato adult population in its education activities.

Five- and six-year follow-up results from four seventh-grade smoking prevention strategies.

Seven thousand one hundred twenty-four members of the Classes of 1985 and 1986 who had participated as seventh graders in one of several smoking prevention programs were tracked and surveyed for smoking habits at 5- and 6-year follow-up: participation exceeded 90% in both cohorts. These data indicated that participants who received seventh-grade interventions based on the social influences model had similar smoking patterns compared to participants in other conditions. This finding supports the call for booster sessions after the initial seventh-grade intervention program. Future follow-up studies will assess whether the earlier benefits associated with the social influences model will translate into measurable differences in adult smoking patterns.

Prevention of relapse in women who quit smoking during pregnancy.

OBJECTIVES This study is an evaluation of relapse prevention interventions for smokers who quit during pregnancy. METHODS Pregnant smokers at 2 managed care organizations were randomized to receive a self-help booklet only, prepartum relapse prevention, or prepartum and postpartum relapse prevention. Follow-up surveys were conducted at 28 weeks of pregnancy and at 8 weeks, 6 months, and 12 months postpartum. RESULTS The pre/post intervention delayed but did not prevent postpartum relapse to smoking. Prevalent abstinence was significantly greater for the pre/post intervention group than for the other groups at 8 weeks (booklet group, 30%; prepartum group, 35%; pre/post group, 39%; P = .02 [different superscripts denote differences at P < .05]) and at 6 months (booklet group, 26%, prepartum group, 24%; pre/post group, 33%; P = .04) postpartum. A nonsignificant reduction in relapse among the pre/post group contributed to differences in prevalent abstinence. There was no difference between the groups in prevalent abstinence at 12 months postpartum. CONCLUSIONS Relapse prevention interventions may need to be increased in duration and potency to prevent post-partum relapse.

Differences in preconceptional and prenatal behaviors in women with intended and unintended pregnancies.

OBJECTIVES This study examined whether pregnancy intention was associated with cigarette smoking, alcohol drinking, use of vitamins, and consumption of caffeinated drinks prior to pregnancy and in early pregnancy. METHODS Data from a telephone survey of 7174 pregnant women were analyzed. RESULTS In comparison with women whose pregnancies were intended, women with unintended pregnancies were more likely to report cigarette smoking and less likely to report daily vitamin use. Women with unintended pregnancies were also less likely to decrease consumption of caffeinated beverages or increase daily vitamin use. CONCLUSIONS Pregnancy intention was associated with health behaviors, prior to pregnancy and in early pregnancy, that may influence pregnancy course and birth outcomes.

Smoking prevalence in a cohort of adolescents, including absentees, dropouts, and transfers.

This study reports daily smoking rates among older adolescents obtained by a unique follow-up of a cohort originally identified in the seventh grade. Those no longer in their original school districts were located and interviewed by telephone. Smoking rates among dropouts exceeded 70 per cent in all age-sex groups. Smoking rates among transfers were as high as those among absentees. Including these subgroups raised smoking prevalence rates among older adolescents substantially.

Smoking cessation in women concerned about weight.

BACKGROUND Weight gain after smoking cessation is often cited by women smokers as a primary reason for not attempting to quit smoking or for relapsing after a cessation attempt. METHODS A randomized trial of 417 women smokers was conducted to test the addition of two weight control strategies to a smoking cessation program. Participants received the standard smoking cessation program, the program plus nicotine gum, the program plus behavioral weight control, or the program plus both nicotine gum and behavioral weight control. Weight and smoking status were measured at the end of treatment and at 6 and 12 months posttreatment. RESULTS Smoking cessation rates were highest in the group receiving the smoking cessation program plus nicotine gum. Weight gain did not vary by treatment condition, so its effect on relapse could not be examined by group. There was no significant relationship between weight gained and relapse in individuals. CONCLUSIONS The added behavioral weight control program was attractive to the participants and did not reduce smoking cessation rates. However, it did not produce the expected effect on weight, thereby restricting our ability to examine the effect of weight control on smoking cessation and relapse.

Community-wide prevention strategies: Evaluation design of the Minnesota Heart Health Program

The Minnesota Heart Health Program (MHHP) is a community-based research and demonstration program designed to accelerate population-wide changes in coronary risk factors and disease. MHHP is on-going in three pairs of communities in Minnesota, North and South Dakota. To strengthen inference of program effects, its basic design involves elements of control, repetition, sensitive trend measurements and evaluation of the effects of program components. Its evaluation design is presented here as a comprehensive measurement system for disease endpoints, risk factor levels and efficacy of specific educational programs. The MHHP design is able to compare risk factor levels and mortality rates between education and comparison communities. MHHP statistical power is sufficient to detect community-wide changes of public health import. Early results show comparability of education and comparison communities for most variables. Widespread community awareness of and participation in MHHP programs is reported.