Change in level of physical activity and risk of all-cause mortality or reinfarction: The Corpus Christi Heart Project.

BACKGROUND: The role of physical activity (PA) in reducing the risk of all-cause mortality or reinfarction after a first myocardial infarction (MI) remains unresolved, particularly for minority populations. The association between change in level of PA and risk of death or reinfarction was studied in 406 Mexican American and non-Hispanic white women and men who survived a first MI. METHODS AND RESULTS: MI patients were interviewed at baseline and annually thereafter about PA, medical history, and risk factors of coronary heart disease. Change in level of PA after the index MI was categorized as (1) sedentary, no change (referent group), (2) decreased activity, (3) increased activity, and (4) active, no change. Over a 7-year period, the relative risk (95% CI) of death was as follows: 0.21 (0.10 to 0.44) for the active, no change group; 0.11 (0.03 to 0.46) for the increased activity group; and 0.49 (0.26 to 0.90) for the decreased activity group. The relative risk of reinfarction was as follows: 0.40 (0.24 to 0.66) for the active, no change group; 0.22 (0.09 to 0.50) for the increased activity group; and 0.93 (0.59 to 1.42) for the decreased activity group. CONCLUSIONS: These findings are consistent with a beneficial role of PA for Mexican American and non-Hispanic white women and men who survive a first MI and have practical implications for the management of MI survivors.

Surgical treatment for intracerebral hemorrhage (STICH): a single-center, randomized clinical trial.

OBJECTIVE: To perform a single-center pilot investigation of early hematoma removal in patients with intracerebral hemorrhage (ICH). BACKGROUND: Considerable debate remains regarding the utility of surgical clot evacuation for ICH. METHODS: This was a prospective trial of open craniotomy within 12 hours of ICH symptom onset versus best medical therapy. Patients were eligible if they had a nontraumatic ICH >9 mL with significant neurologic impairment and were prepared for surgery within 12 hours of symptom onset. The study included a prospective registry of patients and a randomized trial. RESULTS: The registry group included 34 medical and seven surgical patients. The surgical group had larger hemorrhages (median, 96 mL) and a lower Glasgow Coma Scale (GCS) score (median, 10) compared with the medical group (33 mL; GCS score, 13). Six-month mortality was less in the medical group (36%) compared with the surgical group (54%). In the randomized series, median ICH volumes were similar in the surgical group (n = 17; 49 mL) compared with the medical group (n = 17; 44 mL). Median GCS score was also similar (medical, 10; surgical, 11). Mortality was lower in the surgical group (6%) compared with the medical group (24%) at 1 month, but similar at 6 months (surgical group, 17%; medical group, 24%). CONCLUSION: A trial of early surgery for ICH is feasible. This study represents the largest prospective, randomized series of surgery for ICH. A modest early mortality benefit for surgery is possible, but long-term benefit for surgery was not established in this single-center pilot investigation.

Rebleeding leads to poor outcome in ultra-early craniotomy for intracerebral hemorrhage.

BACKGROUND: A modest benefit was previously demonstrated for hematoma evacuation within 12 hours of intracerebral hemorrhage onset. Perhaps surgery within 4 hours would further improve outcome. METHODS: Adult patients with spontaneous supratentorial intracerebral hemorrhage were prospectively enrolled. Craniotomy and clot evacuation were commenced within 4 hours of symptom onset in all cases. Mortality and functional outcome were assessed at 6 months. This group of patients was compared with patients treated within 12 hours of symptom onset using the same surgical and medical protocols. RESULTS: The study was stopped after a planned interim analysis of 11 patients in the 4-hour surgery arm. Median time to surgery was 180 minutes; median hematoma volume was 40 mL; median baseline NIH Stroke Scale score was 19 and Glasgow Coma Scale score was 12. Six-month mortality was 36% and median Barthel score was 75 in survivors. Postoperative rebleeding occurred in four patients, three of whom died. A relationship between postoperative rebleeding and mortality was apparent (p = 0.03). Rebleeding occurred in 40% of the patients treated within 4 hours, compared with 12% of the patients treated within 12 hours (p = 0.11). There was a clear correlation between improved outcome and smaller postsurgical hematoma volume (p = 0.04). CONCLUSIONS: Surgical hematoma evacuation within 4 hours of symptom onset is complicated by rebleeding, indicating difficulty with hemostasis. Maximum removal of blood remains a predictor of good outcome.

Neurologists' attitudes regarding rt-PA for acute ischemic stroke.

We studied the attitudes of 238 Texas neurologists regarding the use of recombinant tissue plasminogen activator (rt-PA). The results show that 38 (16%) had treated stroke patients with rt-PA, and 97% of these would do so again. In the group that had not treated patients, 60% would treat if a suitable candidate presented. We conclude that soon after FDA approval of rt-PA, two-thirds of survey respondents were using or were planning to use this therapy. Those neurologists who have used rt-PA for stroke report a positive experience.

A case-control evaluation of treatment efficacy: the example of magnesium sulfate prophylaxis against eclampsia in patients with preeclampsia.

Randomized trials are the optimal approach for evaluations of treatment efficacy but may not always be feasible. We study the adequacy of the case-control design in evaluating efficacy in a situation where the investigated therapy, namely the administration of magnesium sulfate for the prevention of eclampsia in patients with preeclampsia, has a suspected strong protective effect. A total of 66 cases of eclampsia were ascertained from among deliveries occurring between 1977 and 1992 at two hospitals in Houston, Texas. Randomly selected preeclamptic controls were matched to cases based on hospital and month of delivery. Magnesium sulfate administration prior to seizure occurrence had a strong protective effect against eclampsia in patients with preeclampsia (OR, 0.02; 95% CI, 0.01-0.05). This protective effect remained when controls were stratified by the degree of severity of preeclampsia (mild-to-moderate OR, 0.03, 95% CI, 0.01-0.09 and severe OR, 0.005; 95% CI, 0.0005-0.04) and when cases were stratified by the timing of the first seizure (antepartum and intrapartum seizures OR, 0.01; 95% CI, 0.003-0.05 and postpartum seizures OR, 0.03; 95% CI, 0.005-0.15). The effect also remained after adjustment for other important predictors in a multivariate logistic regression model (OR, 0.11; 95% CI, 0.03-0.38). The results of this study are in support of a recent randomized trial on the efficacy of magnesium sulfate as a prophylactic agent against eclampsia. Although there are serious potential sources of bias in this study, the magnitude of the protective effect of magnesium sulfate minimizes the likelihood that this effect can be explained by bias. Observational studies could be appropriate complements or alternatives to randomized trials in situations where a strong treatment effect is expected.

The effectiveness of a needleless intravenous connection system: an assessment by injury rate and user satisfaction.

OBJECTIVE: To assess the impact of a needleless intravenous (i.v.) connection system on the rate of reported intravenous-connection-related (IVCR) percutaneous injuries, and to assess user satisfaction, frequency of use, and barriers to use. DESIGN: A pre-post intervention design, with injury incidence rates being compared 3 years before and 1 year after hospital wide device implementation; and a cross-sectional descriptive user satisfaction survey. SETTING: Two tertiary-care teaching hospitals, one general and one pediatric, located in a large metropolitan medical center. OUTCOME VARIABLE: All IVCR percutaneous injuries reported to the employee health services at both hospitals during the years from 1989 to 1991 and 1993. STUDY POPULATION: Survey participants were selected randomly from licensed nursing employees at both hospitals. INTERVENTION: i.v. connection system consisting of blunt plastic cannulas and compressed latex injection sites. RESULTS: After device implementation, the IVCR injury rate was reduced 62.4% (rate ratio [RR], 0.38; 95% confidence interval [CI95], 0.27-0.53) at the general hospital and 70.2% (RR, 0.30; CI95, 0.17-0.53) at the pediatric hospital. After adjusting for the reduction in injury rate due to factors other than device implementation, the IVCR injury rate was reduced 54.5% (adjusted RR, 0.46; CI95, 0.32-0.65) at the general hospital and 57.2% (adjusted RR, 0.43; CI95, 0.24-0.78) at the pediatric hospital. Approximately 94% of survey respondents (n = 478, response rate = 51%) were satisfied with the device and recommended continued use. However, needles still were being used for activities that could have been performed with the needleless system because of compatibility, accessibility, and other technical problems related to the device. CONCLUSIONS: The device was effective in reducing the rate of reported IVCR percutaneous injuries and users were satisfied with the device, but barriers to universal use were identified.

Foeto-maternal morbidity in the presence of antibodies to Trypanosoma cruzi.

Pregnancy outcome and maternal morbidity were analysed in 302 pregnant women with positive Machado-Guerreiro Complement Fixation Test (MGCFT) for antibodies to Trypanosoma cruzi and 302 women with a negative MGCFT resident of Córdoba, Argentina. A comparison of positive and negative cases was employed to investigate the association between MGCFT reaction and pregnancy outcome assessed from abortion and perinatal infant mortality rates; similarly, the data were analysed for demographic and socio-economic factors, numbers of previous pregnancies (birth order) and maternal complications. A twofold increase in the risk of pregnancy loss associated with a positive MGCFT was found. The incidence of polyhydramnios and varicosities of the leg was significantly higher in the serologically reactive group.

High-dose barbiturate control of elevated intracranial pressure in patients with severe head injury.

In a five-center study, 73 patients with severe head injury and elevated intracranial pressure (ICP) were randomly assigned to receive either a regimen that included high-dose pentobarbital or one that was otherwise similar but did not include pentobarbital. The results indicated a 2:1 benefit for those treated with the drug with regard to ICP control. When patients were stratified by prerandomization cardiac complications, the advantage increased to 4:1. A multiple logistic model considering treatment and selected baseline variables indicated a significant positive treatment effect of barbiturates, a significant effect of time from injury to randomization, and an interaction of treatment with cardiovascular complications. However, of 925 patients potentially eligible for randomization, only 12% met ICP randomization criteria. The results support the hypothesis that high-dose pentobarbital is an effective adjunctive therapy, but that it is indicated in only a small subset of patients with severe head injury.

Neurobehavioral outcome following minor head injury: a three-center study.

The majority of hospital admissions for head trauma are due to minor injuries; that is, no or only transient loss of consciousness without major complications and not requiring intracranial surgery. Despite the low mortality rate following minor head injury, there is controversy surrounding the extent of morbidity and the long-term sequelae. The authors postulated that consecutively admitted patients who fulfilled research diagnostic criteria for minor head injury and who were carefully screened for antecedent neuropsychiatric disorder and prior head injury would exhibit subacute cognitive and memory deficits that would resolve over a period of 1 to 3 months postinjury. To evaluate this hypothesis, the neurobehavioral functioning of 57 patients was compared within 1 week after minor head injury (baseline) and at 1 month postinjury with that of 56 selected control subjects at three medical centers. Quantified tests of memory, attention, and information-processing speed revealed that neurobehavioral impairment demonstrated at baseline by all means of measurement generally resolved during the first 3 months after minor head injury. Although nearly all patients initially reported cognitive problems, somatic complaints, and emotional malaise, these postconcussion symptoms had substantially resolved by the 3-month follow-up examination. The data suggest that a single uncomplicated minor head injury produces no permanent disabling neurobehavioral impairment in the great majority of patients who are free of preexisting neuropsychiatric disorder and substance abuse.

Prediction of maximum voluntary ventilation (MVV) in African-American adolescent girls.

The purposes of the present study were to: 1) develop original equations to predict maximum voluntary ventilation (MVV) in African-American adolescent girls; and 2) determine the validity of existing MVV prediction equations for use in African-American subjects by comparing predicted MVV values in the literature with actual MVV values obtained in this study. Forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and 12 second MVV were measured with a clinical respirometer (Spirometrics model 2451) in 93 African-American adolescent girls (13.5 +/- 1.0 years). Age (r = 0.29), height (r = 0.38), FEV1 (r = 0.52), and FVC (r = 0.48) were significantly (P < 0.01) correlated with MVV. Multiple regression analysis was used to develop equations to predict MVV with age, height, and FEV1 as predictor variables. Using Mallow's Cp criterion, age-FEV1 and FEV1 equations appeared to be the most accurate predictors of MVV. When MVV was regressed on FEV1 in a non-intercept model, the result was the commonly cited equation MVV = 35.0 x FEV1. Thus, the previously established relationship between FEV1 and MVV can be extended to African-American adolescent girls. Comparison of predicted MVV values calculated from other published equations with our subjects' actual values indicated that equations using age and/or height as predictors did not accurately predict MVV in our subjects.

Maximal exercise hemodynamics and risk of mortality in apparently healthy men and women.

The purpose of this investigation was to determine the association of maximal exercise hemodynamic responses with risk of mortality due to all-causes, cardiovascular disease (CVD), and coronary heart disease (CHD) in a population of apparently healthy individuals. Study participants were 20,387 men (mean age = 42.2 yr) and 6,234 women (mean age = 41.9 yr), patients of a preventive medicine center in Dallas, TX, examined between 1971 and 1989. Maximal heart rate and maximal systolic blood pressure (SBP) measured during the maximal exercise test were related to risk of all-cause, CVD, and CHD mortality. During an average of 8.1 yr of follow-up, there were 348 deaths in men and 66 deaths in women. Among men, after adjustment for confounding variables, risks (and 95 percent confidence interval (CI)) of all-cause mortality for quartiles of maximal SBP, relative to the lowest quartile, were: 0.96 (0.70-1.33), 1.36 (1.01-1.85), and 1.37 (0.98-1.92) for quartiles 2-4, respectively. Similarly adjusted risks for maximal heart rate were: 0.61(0.44-0.85), 0.69 (0.51-0.93), and 0.60 (0.41-0.87). Similar results were seen for risk of CVD and CHD death. In women, similar trends in adjusted risks of all-cause and CVD mortality across maximal SBP and heart rate categories were observed. For maximal heart rate, a 35 bpm higher value was associated with a 36 percent decreased risk of CVD mortality in men (RR = 0.63,95 percent CI = 0.34-0.71) and an 8 percent lower risk in women (RR = 0.92,95 percent CI = 0.18-4.63). These results suggest that an exaggerated SBP or an attenuated heart rate response to maximal exercise may indicate an elevated risk for mortality in this apparently healthy population.

A meta-analysis of trials evaluating patient education and counseling for three groups of preventive health behaviors.

OBJECTIVES: To examine the overall effectiveness of patient education and counseling on preventive health behaviors and to examine the effects of various approaches for modifying specific types of behaviors. DATA SOURCES: Computerized databases (Medline, Healthline, Dissertation Abstracts, and Psychological Abstracts), bibliographies 1971-1994. Search terms (patient education, patient compliance, and self care) with modifiers (evaluation and specific preventive behaviors). STUDY SELECTION: Randomized and non-randomized controlled trials measuring behavior in clinical settings with patients without diagnosed disease. Abstracts and retrieved studies screened by multiple reviewers; 13% of retrieved studies met screening criteria. DATA EXTRACTION: Replicated coding by multiple observers. DATA SYNTHESIS: Behaviors were grouped based on whether the behavior is addictive and whether the desired change required subtraction of existing behaviors or adding new behaviors. The weighted average effect size from a random effects model for smoking/alcohol studies was 0.61 (CI = 0.45, 0.77), for nutrition/weight, 0.51 (CI = 0.20, 0.82) and for other behaviors, 0.56 (CI = 0.34, 0.77) indicating that the behavioral outcomes for these subgroups were significantly different from zero. Multiple regression models for the three groups indicated that using behavioral techniques, particularly self-monitoring, and using several communication channels, e.g., media plus personal communication, produces larger effects for the smoking/alcohol and nutrition/weight groups. CONCLUSIONS: Patient education and counseling contribute to behavior change for primary prevention of disease. Some techniques are more effective than others in changing specific behaviors.

Alcohol consumption and nearly lethal suicide attempts.

We conducted a case-control study of the association between nearly lethal suicide attempts and facets of alcohol consumption; namely, drinking frequency, drinking quantity, binge drinking, alcoholism, drinking within 3 hours of suicide attempt, and age began drinking. Subjects were 13-34 years of age. In bivariable analyses, all measures were associated with nearly lethal suicide attempts. Odds ratios ranged from 2.4 for alcoholism to 7.0 for drinking within 3 hours of attempt. All exposure variables except age began drinking exhibited a J-shaped relationship between alcohol exposure and nearly lethal suicide attempt. After controlling for potential confounders and other measures of alcohol exposure, drinking within 3 hours of attempt remained most strongly (odds ratios > 6) associated. Alcoholism remained significantly associated in most models, but at lower strength.

An unmatched case-control study of nearly lethal suicide attempts in Houston, Texas: research methods and measurements.

This article details the research methods and measurements used in conducting a population-based, case-control study of nearly lethal suicide attempts among persons aged 13-34 years, residing in Houston, Texas. From November 1992 to July 1995, we interviewed 153 case subjects presenting at one of three participating hospital emergency departments and used random digit dialing to identify 513 control subjects residing in the same catchment area in which cases were enlisted. Unlike most research in this area, this study was designed to extend our understanding of suicidal behavior and prevention activities beyond identification and treatment of depression and other mental illnesses. We discuss the overall strengths and weaknesses of our study design and conclude that this methodology is well suited for studying rare outcomes such as nearly lethal suicide.

The influence of geographic mobility on nearly lethal suicide attempts.

Teenagers and young adults are very mobile and mobility has been identified as a potential risk factor for suicidal behavior. We conducted a population-based, case-control study of nearly lethal suicide attempts with 153 cases and 513 controls. Study participants were asked about changing residence over the past 12 months. Results indicate that moving in the past 12 months is positively associated with a nearly lethal suicide attempt (adjusted odds ratio of 2.1, with 95% confidence interval of 1.4-3.3), as are specific characteristics of the move (e.g., frequency, recency, distance, and difficulty staying in touch). These findings confirm and extend prior ecologic research by demonstrating a relationship, at the individual level, between the geographic mobility of adolescents and young adults and nearly lethal suicide attempts.

Identification of nearly fatal suicide attempts: Self-Inflicted Injury Severity Form.

The Self-Inflicted Injury Severity Form (SIISF) was developed as an epidemiological research tool for identifying individuals in hospital emergency departments who have life-threatening self-inflicted injuries. Data were collected from 715 patients with self-inflicted injuries in two large hospitals. In 295 of these cases, a second set of data was independently collected for assessment of interrater reliability. Validity was assessed by comparing the SIISF results with simultaneously collected Risk-Rescue Ratings. Assessment of interrater reliability found that only 2.4% of physicians disagreed on the suicide method used. The kappa statistic for method used was .94, indicating excellent agreement. The SIISF was found to distinguish between severe and less severe injuries. Thus, it appears to provide a simple method to distinguish patients who have life-threatening self-inflicted injuries.

Definition and yield of inclusion criteria for a meta-analysis of patient education studies in clinical preventive services.

Because selection of studies for a literature review influences conclusions, inclusion criteria are of utmost importance. For a meta-analysis of studies testing effects of patient education on preventive behaviors, we present the framework and concepts used for setting inclusion criteria for primary studies. We also present the yield in terms of number and distribution of studies that resulted from the inclusion criteria. Because we were interested in a diverse range of behaviors and a broad definition of patient education, we present a method for grouping behaviors by type of behavior change and describe parameters for subgrouping interventions by orientation and communication channel. Of 5,451 citations located and abstracts screened, 561 citations reporting potentially relevant studies were reviewed. Based on our inclusion criteria, 171 citations contained relevant studies, of which 64 studies (found in 62 citations) also met our acceptability criteria. We examine the effects of alternate inclusion criteria on the yield of primary studies and their distributions across the subgroupings.

Effect of unequal censoring on the size and power of the logrank and Wilcoxon types of tests for survival data.

This paper examines the effect of random unequal censoring on the size and power of two-sample logrank and Wilcoxon types of tests for comparing two survival distributions by simulation with small samples from censored exponential distributions. We compared equal-sized samples of n = 8, 16, and 32 with 1000 (size) and 500 (power) simulation trials for 16 combinations of the censoring proportions of 0, 20, 40, and 60 per cent in each of the two samples. For n = 8, the asymptotic normality (AN), Peto-Peto, and the two Wilcoxon-type tests performed at nominal 5 per cent size expectations, but the Mantel test exceeded the 5 per cent size acceptance region in 6 of 16 censoring combinations. For n = 16 and 32, all tests showed proper size, with the Peto-Peto test being most conservative in the presence of unequal censoring. We compared powers of all tests for exponential hazard ratios of 1.4 and 2.0. The Mantal test showed 90 to 95 per cent power efficiency relative to the parametric AN test. Both Wilcoxon tests performed identically and had the lowest relative power of all tests examined but appeared most robust to the differential censoring patterns studied. A modified version of the Peto-Peto test showed power comparable to the Mantel test.