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S M McKinlay

Publications and source records attributed to S M McKinlay.

At least 19 recordsLinked to original sources
PubMed1999

Early revascularization in acute myocardial infarction complicated by cardiogenic shock. SHOCK Investigators. Should We Emergently Revascularize Occluded Coronaries for Cardiogenic Shock.

BACKGROUND: The leading cause of death in patients hospitalized for acute myocardial infarction is cardiogenic shock. We conducted a randomized trial to evaluate early revascularization in patients with cardiogenic shock. METHODS: Patients with shock due to left ventricular failure complicating myocardial infarction were randomly assigned to emergency revascularization (152 patients) or initial medical stabilization (150 patients). Revascularization was accomplished by either coronary-artery bypass grafting or angioplasty. Intraaortic balloon counterpulsation was performed in 86 percent of the patients in both groups. The primary end point was mortality from all causes at 30 days. Six-month survival was a secondary end point. RESULTS: The mean age of the patients was 66+/-10 years, 32 percent were women and 55 percent were transferred from other hospitals. The median time to the onset of shock was 5.6 hours after infarction, and most infarcts were anterior in location. Ninety-seven percent of the patients assigned to revascularization underwent early coronary angiography, and 87 percent underwent revascularization; only 2.7 percent of the patients assigned to medical therapy crossed over to early revascularization without clinical indication. Overall mortality at 30 days did not differ significantly between the revascularization and medical-therapy groups (46.7 percent and 56.0 percent, respectively; difference, -9.3 percent; 95 percent confidence interval for the difference, -20.5 to 1.9 percent; P=0.11). Six-month mortality was lower in the revascularization group than in the medical-therapy group (50.3 percent vs. 63.1 percent, P=0.027). CONCLUSIONS: In patients with cardiogenic shock, emergency revascularization did not significantly reduce overall mortality at 30 days. However, after six months there was a significant survival benefit. Early revascularization should be strongly considered for patients with acute myocardial infarction complicated by cardiogenic shock.

Aged↗
PubMed1999

SHould we emergently revascularize Occluded Coronaries for cardiogenic shocK: an international randomized trial of emergency PTCA/CABG-trial design. The SHOCK Trial Study Group.

BACKGROUND: Cardiogenic shock (CS) is the leading cause of death in patients hospitalized with acute myocardial infarction (MI). Nonrandomized studies suggest reduced mortality rate with revascularization. TRIAL DESIGN: The SHOCK trial is a multicenter, randomized, and unblinded study with a Registry for trial-eligible and ineligible nonrandomized patients. The trial is testing the hypothesis that a direct invasive strategy of emergency revascularization for patients with cardiogenic shock complicating acute MI will reduce 30-day all-cause mortality rate by 20 absolute percentage points compared with initial medical stabilization. Eligibility criteria include development of CS within 36 hours of an acute transmural MI as evidenced by ST elevation or new left bundle branch block MI; clinical criteria for CS with hemodynamic confirmation; absence of a mechanical, iatrogenic, or other cause of shock; and enrollment within 12 hours of CS diagnosis. Patients randomly assigned to emergency revascularization immediately undergo coronary angiography, with percutaneous transluminal coronary angioplasty or coronary artery bypass grafting depending on the coronary anatomy. Patients assigned to initial medical stabilization may undergo revascularization >/=54 hours after randomization. END POINTS: The primary end point is all-cause 30-day mortality after randomization. Secondary end points include death at trial termination, changes in left ventricular dimensions and function measured by echocardiography at randomization and 2 weeks later, and changes in quality of life and physical functioning from 2 weeks after discharge to 6 months after MI.

Angioplasty, Balloon, Coronary↗
PubMed1997

Psychosocial, behavioral, and health factors related to menopause symptomatology.

Despite wide variation in the reporting of hot flashes and night sweats among menopausal women, what differentiates symptomatic from asymptomatic women is not well understood. In this article, we use longitudinal data from a large cohort of initially premenopausal women to address premenopausal factors predictive of length of the perimenopause, frequency of hot flash/night sweat (HF/NS) reporting, bothersomeness of HF/NS, and treatment seeking during menopause. The sample for analysis consists of 454 women from the Massachusetts Women's Health Study who were premenopausal at baseline and postmenopausal by the sixth and last study follow-up. Each of the four study outcomes was modeled as a function of premenopausal characteristics using logistic regression. Results confirm a wide range of symptom reporting, with 23% of women not reporting HF/NS at any of the six interviews. Variables related to greater frequency of HF/NS reporting included a longer perimenopause, more psychological and physical symptoms prior to menopause, lower education, and more negative attitudes toward menopause prior to menopause. Symptom bothersomeness was related to greater frequency of HF/NS reporting, smoking, and being divorced. Variables that predicted medical doctor consultation were greater frequency and bothersomeness of symptoms, higher education, and greater health care utilization. We conclude that general symptom reporting, attitudes toward menopause, and lifestyle factors can explain some of the individual variation in symptom reporting.

Attitude to Health↗
PubMed1996

Outcomes of a field trial to improve children's dietary patterns and physical activity. The Child and Adolescent Trial for Cardiovascular Health. CATCH collaborative group.

OBJECTIVE: To assess the outcomes of health behavior interventions, focusing on the elementary school environment, classroom curricula, and home programs, for the primary prevention of cardiovascular disease. DESIGN: A randomized, controlled field trial at four sites with 56 intervention and 40 control elementary schools. Outcomes were assessed using prerandomization measures (fall 1991) and follow-up measures (spring 1994). PARTICIPANTS: A total of 5106 initially third-grade students from ethnically diverse backgrounds in public schools located in California, Louisiana, Minnesota, and Texas. INTERVENTION: Twenty-eight schools participated in a third-grade through fifth-grade intervention including school food service modifications, enhanced physical education (PE), and classroom health curricula. Twenty-eight additional schools received these components plus family education. MAIN OUTCOME MEASURES: At the school level, two primary end points were changes in the fat content of food service lunch offerings and the amount of moderate-to-vigorous physical activity in the PE programs. At the level of the individual student, serum cholesterol change was the primary end point and was used for power calculations for the study. Individual level secondary end points included psychological factors, recall measures of eating and physical activity patterns, and other physiologic measures. RESULTS: In intervention school lunches, the percentage of energy intake from fat fell significantly more (from 38.7% to 31.9%) than in control lunches (from 38.9% to 36.2%)(P<.001). The intensity of physical activity in PE classes during the Child and Adolescent Trial for Cardiovascular Health (CATCH) intervention increased significantly in the intervention schools compared with the control schools (P<.02). Self-reported daily energy intake from fat among students in the intervention schools was significantly reduced (from 32.7% to 30.3%) compared with that among students in the control schools (from 32.6% to 32.2%)(P<.001). Intervention students reported significantly more daily vigorous activity than controls (58.6 minutes vs 46.5 minutes; P<.003). Blood pressure, body size, and cholesterol measures did not differ significantly between treatment groups. No evidence of deleterious effects of this intervention on growth or development was observed. CONCLUSION: The CATCH intervention was able to modify the fat content of school lunches, increase moderate-to-vigorous physical activity in PE, and improve eating and physical activity behaviors in children during 3 school years.

Analysis of Variance↗
PubMed1996

The normal menopause transition: an overview.

OBJECTIVES: This review emphasizes results from population based studies in order to provide a reliable knowledge base and define major knowledge gaps for future research. METHODS: The review systematically addresses the following aspects of menopause research: definition of menopause and menopause transitions; age at natural menopause and at inception of perimenopause; factors affecting timing and length of menopause transitions; concurrent hormone, menstrual and vascular changes. Under each substantive heading, available reports of original research are reviewed, assessed for reliability and summarized with respect to their contribution to the knowledge base. RESULTS: From this review, the following reliable information can be summarized: median age at natural menopause in Caucasian women occurs between 50 and 51-55 years of age, is not affected by timing of surgical menopause and is affected by cigarette smoking, with current smokers having an earlier menopause by 1.5-2.0 years. No other factors appear to have an independent effect on age at menopause. There is no evidence of any secular trend in age at menopause. Evidence is accumulating that most physiological change associated with menopause either occurs or begins before the final menstrual period. CONCLUSIONS: We lack reliable information on the following: estimates of age at menopause from non-industrialized countries and diverse ethnic groups; information on perimenopause; differing perceptions of menopause, cross culturally; multi-disciplinary prospective data that can link various processes into coherent patterns.

Adult↗
PubMed1996

Does collecting repeated blood samples from each subject improve the precision of estimated steroid hormone levels?

Measuring levels of steroid hormones in epidemiologic studies is difficult because pulsatile release can cause the levels of many hormones to vary markedly over short intervals, leading to a loss of precision in between-subject comparisons. Clinicians often control this variation by collecting several samples from each subject at defined intervals and pooling these samples for assay. The number of samples per subject that would adequately control such variation in an epidemiologic study has not been fully investigated. This study examines the effects of collecting 1, 2, or 3 samples per subject on the variances of 11 hormones and sex hormone binding globulin in men and 6 hormones in women. Three samples were collected at 30-minute intervals from each of 20 men and 59 women and were assayed separately. Variances that would be obtained in studies collecting one, two, or three samples per subject were then estimated. Collecting more than one sample substantially reduced the variances of several hormones in men but not in women.

Adult↗
PubMed1996

Batch sampling to improve power in a community trial. Experience from the Pawtucket Heart Health Program.

Experiments involving large social units, such as schools, work sites, or whole cities, are commonly limited in statistical power because the number of randomized units is small, leaving few degrees of freedom for residual (between-unit) error. The authors describe a method for increasing residual degrees of freedom in a community experiment without substantially increasing cost or difficulty. In brief, they propose that the experimental units should be divided into random subsamples (batches). Batch sampling can improve statistical power if the community endpoint means are stable over time or if their temporal variation is comparable in period to the batch-sampling schedule. The authors demonstrate the theoretical advantages of the batch system and illustrate its use with data from the Pawtucket Heart Health Program, in which such a design was implemented.

Analysis of Variance↗
PubMed1995

Statistical design of the Child and Adolescent Trial for Cardiovascular Health (CATCH): implications of cluster randomization.

This paper describes some statistical considerations for the Child and Adolescent Trial for Cardiovascular Health (CATCH), a large-scale community health trial sponsored by the National Heart, Lung, and Blood Institute. The trial involves randomization of entire schools rather than individual students to the experimental arms. The paper discussed the implications of this form of randomization for the design and analysis of the trial. The power calculations and analysis plan for the trial are presented in detail. The handling of outmigrating and immigrating students is also discussed.

Adolescent↗
PubMed1994

Defining the perimenopause for application in epidemiologic investigations.

The authors present a method for defining the inception of perimenopause that is based on self-reported data. The study sample (n = 1,550) was obtained from a 5-year longitudinal study of 2,569 Massachusetts women aged 45-55 years that began in 1981. The definition was derived from the ability of responses to questions concerning timing of the last menstrual period, menstrual regularity, and presence of menopausal symptoms (hot flashes/sweats) to predict menopause 3 years later. The two items that best defined the inception of perimenopause were 3-11 months of amenorrhea and increased menstrual irregularity for those without amenorrhea. This definition can easily be used in large epidemiologic investigations.

Female↗
PubMed1994

Longitudinal patterns and correlates of hormone replacement therapy use in middle-aged women.

Patterns of hormone replacement therapy (HRT) use over time and predictors of initiating or discontinuing use were examined in a longitudinal study. A cohort of 2,425 women aged 45-55 years identified from a population-based random survey in Massachusetts in 1981-1982 was followed by six telephone interviews, 9 months apart. Cohort participants were either premenopausal (66.8%) or in early perimenopause (33.2%). During the study, prevalence of use was low overall (12.3%) and was considerably higher for surgical menopause (45%) than for peri- (9.3%), natural (4.5%), or premenopause (1.5%). Predictors of HRT uptake and discontinuation (from time t - 1 to time t) were examined by repeated-measures logistic regression, stratified by surgical status. For surgical menopause, the only significant predictor of HRT uptake was recent surgery (odds ratio = 4.4; 95% confidence interval 2.73-7.22), while for nonsurgical subjects, menopausal status (primarily perimenopause), prior use of HRT, health care utilization, hot flashes, alcohol consumption, regular exercise, and leaner body mass were all significant predictors of uptake. Discontinuing HRT was inversely associated with surgical and perimenopause and positively related to prior short-term use and health care utilization. Nonsurgical HRT users had a somewhat more favorable cardiovascular risk profile than did nonusers.

Climacteric↗
PubMed1994

Cohort versus cross-sectional design in large field trials: precision, sample size, and a unifying model.

In planning large longitudinal field trials, one is often faced with a choice between a cohort design and a cross-sectional design, with attendant issues of precision, sample size, and bias. To provide a practical method for assessing these trade-offs quantitatively, we present a unifying statistical model that embraces both designs as special cases. The model takes account of continuous and discrete endpoints, site differences, and random cluster and subject effects of both a time-invariant and a time-varying nature. We provide a comprehensive design equation, relating sample size to precision for cohort and cross-sectional designs, and show that the follow-up cost and selection bias attending a cohort design may outweigh any theoretical advantage in precision. We provide formulae for the minimum number of clusters and subjects. We relate this model to the recently published prevalence model for COMMIT, a multi-site trial of smoking cessation programmes. Finally, we tabulate parameter estimates for some physiological endpoints from recent community-based heart-disease prevention trials, work an example, and discuss the need for compiling such estimates as a basis for informed design of future field trials.

Analysis of Variance↗
PubMed1994

Cost-efficient designs of cluster unit trials.

BACKGROUND: Large field trials that randomize naturally occurring clusters such as communities, worksites, or schools are becoming widely accepted for evaluating complex interventions. The within-cluster measurement of individuals typically uses a cohort, followed throughout the trial or cross-sectional samples selected independently at each time point. The relative costs of these approaches is of concern in designing such trials. METHODS: This paper takes the unified model for analyzing large cluster unit trials developed by Feldman and McKinlay (Stat Med 1993) and combines the resulting expression for the variance of the treatment effect with a simple cost function into an algorithm that produces the optimal trial design in terms of the number of clusters and the number of observations per cluster. Using the unified model developed in the prior paper, this algorithm also allows direct comparison of the cost of designs with equivalent precision. In particular, designs that use cohorts in each cluster unit and observe cohort members over time are contrasted with designs that draw independent cross-sectional samples from each cluster at each time point. RESULTS: Using the algorithm and a realistic design problem, it is demonstrated that cohort designs are more cost efficient for short trials and high (> or = 0.75) autocorrelations. CONCLUSIONS: The power of the algorithm in designing cost-efficient cluster unit trials is well demonstrated. Estimates of variance and cost components from prior trials need to be readily accessible for use in the algorithm, for planning subsequent trials.

Algorithms↗
PubMed1994

A longitudinal analysis of the association between menopause and depression. Results from the Massachusetts Women's Health Study.

The present article prospectively examines the effect of change in menopause status on depression, while controlling for prior depression. This is a longitudinal follow-up of previous cross-sectional analyses reported by McKinlay, McKinlay, and Brambilla who examined the relative contribution of menopause to depression. The data derive from the Massachusetts Women's Health Study, a 5-year longitudinal study of a cohort of 2565 women aged 45 to 55 years at baseline (1981 to 1982). Results show that prior depression is the variable most predictive of subsequent depression, as measured by the Center for Epidemiologic Studies-Depression (CES-D) scale. Onset of natural menopause was not associated with increased risk of depression. Experiencing a long perimenopausal period (at least 27 months), however, was associated with increased risk of depression. The association between a long perimenopause and depression appeared to be explained by increased menopausal symptoms rather than by the menopause status itself. The observed increase in depression during a lengthy perimenopause appears to be transitory.

Climacteric↗
PubMed1993

Caffeine and other predictors of bone density among pre- and perimenopausal women.

We evaluated the influence of dietary, anthropomorphic, and hormonal factors on bone density in a cross-sectional sample of 281 pre- and perimenopausal women age 50-60 years living in Massachusetts. The sample included only women who had intact ovaries and were not currently using estrogen. Information on diet was obtained through a semiquantitative food frequency questionnaire. We measured bone density using single-photon absorptiometry in the non-dominant arm in two sites: the midshaft and the ultradistal radius. We observed no important associations between midshaft bone density and dietary variables but found linear relations between ultradistal radius bone density and body mass index [b = 1.10 gm/cm2 per kg/m2, standard error (SE) = 0.56], follicle-stimulating hormone (FSH) (b = -0.36 gm/cm2 per IU/liter, SE = 0.15), and several nutrients: calcium (b = 0.012 gm/cm2 per mg/day, SE = 0.007), retinol (b = 0.002 gm/cm2 per IU/day, SE = 0.0008), vitamin C (b = 0.025 gm/cm2 per mg/day, SE = 0.013), and vitamin D (b = 0.040 gm/cm2 per IU/day, SE = 0.018). We could not clearly distinguish the independent contribution of these micronutrients, however, because many were commonly ingested together in the form of supplements. Caffeine was inversely associated with bone density (b = -0.035, SE = 0.017) independent of dietary, anthropometric, and hormonal factors. Analyses of individual caffeinated beverages revealed consistent inverse associations for coffee (b = -3.42 gm/cm2 per cups/day, SE = 1.49), tea (b = -2.85 gm/cm2 per cups/day, SE = 1.56), and caffeinated cola (b = -14.0 gm/cm2 per cans/day, SE = 5.1), but not for decaffeinated coffee or decaffeinated cola [corrected]. [ABSTRACT TRUNCATED AT 250 WORDS)

Anthropometry↗
PubMed1993

Hemophilia growth and development study. Design, methods, and entry data.

PURPOSE: The study design, research questions, and baseline data are presented from a multicenter longitudinal epidemiologic investigation of the impact of human immunodeficiency virus (HIV) infection on three areas of functioning in children and adolescents with hemophilia: physical growth and sexual maturation, immune function, and neurological and neuropsychological functioning. PATIENTS AND METHODS: Sixty-nine percent (n = 333) of a population of males between the ages of 6 and 19 years with moderate to severe hemophilia participated in a comprehensive baseline examination. Approximately 62% of the study group was HIV seropositive and 38% HIV seronegative. RESULTS: Adjusted for age, HIV-positive participants were three times as likely as HIV-negative participants to exhibit declines in height-for-age attainment (p = 0.05), twice as likely to have delays in sexual maturation (p = 0.414), and more than three times as likely to exhibit antibody levels that were not indicative of prior exposure or vaccination (p < 0.001). In addition, analysis of a comprehensive battery of neuropsychological tests showed that HIV-positive participants were 50% more likely to show scores approximately 1 SD below expected levels in three of nine functional areas (p = NS) compared with HIV-negative participants. CONCLUSIONS: Entry data for this study reveal a greater likelihood for HIV-positive children and adolescents with moderate to severe hemophilia to have abnormal growth, and to exhibit antibody levels not indicative of prior exposure to disease or vaccination, which could be attributed to HIV infection. Lowered neuropsychological test performance in both groups may be attributable to the deleterious effects of chronic illness. Data are being collected from a group of non-HIV infected non-hemophiliac siblings for comparison.

Adolescent↗
PubMed1993

Correlates of the prevalence of self-reported hypertension among African-American and white women.

This study examines self-reported hypertension and its correlates in a random sample of 5539 African-American and white middle-aged women residing in Massachusetts. African-American women reported hypertension more frequently than did whites (38.2% vs 19.8%). African-American women were more likely than white women to have seen a doctor in the preceding year and to have had a hysterectomy. The African-American women were less likely to be current smokers and were less educated than white women. Stepwise logistic regression revealed that self-reported hypertension was associated with race, education, health care utilization, and the interaction of education and race. Prevalence differences between African Americans and whites declined with increasing education. However, the model indicates that after controlling for differences in socioeconomic status (based on education) and health care utilization, self-reported hypertension was still more prevalent among African-American women.

Black or African American↗
PubMed1992

The normal menopause transition.

This paper presents analyses from perhaps the largest and most comprehensive prospective cohort study of mid-aged women--the Massachusetts Women's Health Study (MWHS)--with numbers sufficient to provide, for the first time, stable estimates of parameters in the normal menopause transition. The three questions addressed in this analysis are (i) what are the natural menopause transitions and when do they occur, (ii) what factors affect these transitions and (iii) what signs and/or symptoms accompany these transitions? The data were obtained primarily from 5 years of follow-up of 2570 women in Massachusetts who were aged 45-55 years as of January 1, 1982. An initial baseline cross-sectional survey (T0) yielded a total of 8050 completed responses with an overall response rate of 77%. From this cross-sectional sample a cohort of approximately 2570 women was identified, consisting of women who had menstruated in the preceding 3 months and who had not undergone removal of the uterus and/or ovaries. Prospective study of the cohort consisted of six telephone contacts (T1-T6) at 9-month intervals with excellent retention of the respondents. A subset of the full cohort was defined that consisted of women who were premenopausal (rather than perimenopausal) at baseline (T0) (n = 1178). Confirming prior reports, the age at natural menopause occurred at 51.3 years with a highly significant median difference (1.8 years) between current smokers and non-smokers. The new analyses reported here on median age at inception of perimenopause (47.5 years) and factors affecting it are consistent with findings for age at last menstrual period, particularly the overwhelming effect of smoking. Smokers tend to have not only an earlier but also a shorter perimenopause. The length of the perimenopausal transition (estimated at nearly 4 years) has not been previously reported. Moreover, the highest rate of physician consultations is observed among those with longer perimenopause transitions. The relationship between menopause transitions and symptom reporting appears to be transitory, with reported rates showing an increase in the perimenopause and a compensatory decrease in the postmenopause. The implications of combined hormone replacement therapy for future research on menopause in industrial societies is discussed in relation to these findings.

Age Factors↗