A prospective cohort study evaluating the state of medical readiness in the United States Air Force and risk factors to improve the medical readiness posture

A cohort of 418 United States Air Force (USAF) personnel from over 15 different bases deployed to Morocco in 1994. This was the first study of its kind and was designed with two primary goals: to determine if the USAF was medically prepared to deploy with its changing mission in the new world order, and to evaluate factors that might improve or degrade USAF medical readiness. The mean length of deployment was 21 days. The cohort was 95% male, 86% enlisted, 65% married, and 78% white.^ This study shows major deficiencies indicating the USAF medical readiness posture has not fully responded to meet its new mission requirements. Lack of required logistical items (e.g., mosquito nets, rainboots, DEET insecticide cream, etc.) revealed a low state of preparedness. The most notable deficiency was that 82.5% (95% CI = 78.4, 85.9) did not have permethrin pretreated mosquito nets and 81.0% (95% CI = 76.8, 84.6) lacked mosquito net poles. Additionally, 18% were deficient on vaccinations and 36% had not received a tuberculin skin test. Excluding injections, the overall compliance for preventive medicine requirements had a mean frequency of only 50.6% (95% CI = 45.36, 55.90).^ Several factors had a positive impact on compliance with logistical requirements. The most prominent was "receiving a medical intelligence briefing" from the USAF Public Health. After adjustment for mobility and age, individuals who underwent a briefing were 17.2 (95% CI = 4.37, 67.99) times more likely to have received an immunoglobulin shot and 4.2 (95% CI = 1.84, 9.45) times more likely to start their antimalarial prophylaxsis at the proper time. "Personnel on mobility" had the second strongest positive effect on medical readiness. When mobility and briefing were included in models, "personnel on mobility" were 2.6 (95% CI = 1.19, 5.53) times as likely to have DEET insecticide and 2.2 (95% CI = 1.16, 4.16) times as likely to have had a TB skin test.^ Five recommendations to improve the medical readiness of the USAF were outlined: upgrade base level logistical support, improve medical intelligence messages, include medical requirements on travel orders, place more personnel on mobility or only deploy personnel on mobility, and conduct research dedicated to capitalize on the powerful effect from predeployment briefings.^ Since this is the first study of its kind, more studies should be performed in different geographic theaters to assess medical readiness and establish acceptable compliance levels for the USAF. ^

Knowledge, beliefs, risk behaviors, and social skills for HIV/STD prevention in junior college students (grades 11--12) in Bombay, India

1230 year 11 and 12 college students, modal age 16 and 17, in three colleges in Bombay, India, were studied on sexual behaviors or risk of sexual behaviors, beliefs about sex, HIV/STD knowledge, perceived norms regarding sexual behaviors, and the relationships between social skills/anxieties in HIV/STD prevention and actual and anticipated sexual behaviors. A quantitative questionnaire examining HIV/STD risk behaviors, knowledge, attitudes and beliefs, and the AIDS Social Assertiveness Scale (ASAS) were administered to these 1230 college students. Data indicated that 8% of males and 1% of females had had sexual experience, but over one third were not sure at all of being able to abstain from sexual activity with either steady or casual partners. Perceived norms were slanted toward sexual abstinence for the majority of the sample. Knowledge of protective effects of condoms was high, although half of those who had had sex did not use condoms. Logistic regression showed knowledge was higher among males, those who believed it was OK to have sex with a steady partner and that they should not wait until they were older, those who believed that condoms should be used even if the partner is known, and those who believed it was acceptable to have multiple partners. Gender differences in sexual activity and beliefs about sexual activity showed males were less likely to believe in abstaining from sexual activity. The 5 scales of the ASAS were scored and compared on ANOVA on: those who had had sexual experience (HS), those who anticipated being unable to refuse sex (AS), and those who did not anticipate problems in refusing sex (DS). Those in the AS group had greater anxieties about refusing sexual or other risk behaviors than HS and DS groups. There were greater anxieties about dealing with condoms in the AS and DS groups compared with the HS group. Confiding sexual or HIV/STD-related problems to significant others was more anxiety-provoking for the AS group compared with the HS group, and the AS group were more anxious about interactions with people with HIV. Factor analysis produced the same 5 factors as those found in previous studies. Of these, condom interactions and confiding in significant others were most anxiety provoking, and condom interactions most variable based on demographic and attitudinal factors.^ This age group is appropriate for HIV/STD reduction education given the low rate of sexual activity but despite knowledge of the importance of condom use, social skills to apply this knowledge are lacking. Social skills training in sexual negotiations, condom negotiations, and confiding HIV/STD-related concerns to significant others should reduce the risks of Indian college students having unwanted or unprotected sex. ^

Middle managers' attitudes toward employee assistance programs in the corporate setting

Several studies have shown that successful Employee Assistance Programs (EAPs) have strong management endorsement. Strong management endorsement is defined as positive support in utilizing EAP services for themselves and their employees. This study focuses solely on middle management as opposed to upper or general management support. The study further examines success or lack of success of an EAP by the utilization rate defined as the number of employees over a year period who access EAP services.^ A analytical cross-sectional design was used to compare and observe differences between two groups of middle managers (utilizers and nonutilizers). Middle manager data was collected through a mail questionnaire. The study focused on identifying predictors that influence middle managers' utilization rate specifically: attitude toward EAPs, EAP knowledge level, attitude toward mental health professionals, age, gender, years worked as a middle manager, education level, training, and other possible predictors of utilization. The overall hypothesis states middle manager utilizers of EAP services have more positive attitudes and a better understanding of their EAP than middle management nonutilizers.^ As predicted, nonparametric bivariate results showed significant differences between the two groups. Middle managers in the utilization group (n = 473) tended to show more positive attitudes toward their EAP and mental health professionals and demonstrated greater EAP knowledge compared to the nonutilization group (n = 154). These findings support past studies on variables that influence EAP utilization rates.^ Further variables found to influence middle management utilization were identified by multivariate logistic regression results. These variable were gender (female supervisors), educational levels of employees supervised (employees with lower levels of education), number of employees supervised (greater the number supervised, more likely to utilize), managerial EAP training (trained supervisors) and awareness that problems do influence an employee's productivity.^ These findings strengthen the assertion that middle management's attitudes, as well as other variables may influence utilization. Study findings add new information about important variables specifically influencing middle management who utilize EAPs. An understanding of these variables is essential in developing competent EAP program training and orientation programs for middle managers. ^

The epidemiology of chronic fatigue in San Francisco

Chronic fatigue syndrome (CFS) is a recently defined condition characterized by severe disabling fatigue that persists for a minimum of six months, and a host of somatic and neurocognitive symptoms. Although conditions similar to CFS have been described in the medical literature for over 100 years, little is known about the epidemiology of CFS or of chronic fatigue generally. The San Francisco Fatigue Study was undertaken to describe the prevalence and characteristics of self-reported chronic fatigue and associated conditions in a diverse urban community. The study utilized a cross-sectional telephone survey of a random sample of households in San Francisco, followed by case/control interviews of fatigued and nonfatigued subjects. Respondents were classified as chronically fatigued (CF) if they reported severe fatigue lasting six months or longer, then further classified as having CFS-like illness if, based on self-reported information, their condition appeared to meet CFS case definition criteria. Subjects who reported idiopathic chronic fatigue that did not meet CFS criteria were classified as having ICF-like illness.^ 8004 households were screened, yielding fatigue and demographic information on 16970 residents. CF was reported by 635 persons, 3.7% of the study population. CFS-like illness was identified in 34 subjects (0.2%), and ICF-like illness in 259 subjects (1.6%). Logistic regression analysis indicated that prevalence odds ratios for CFS-like illness were significantly elevated for females compared to males (OR = 2.9), and in Blacks (OR = 2.9) and Native Americans (OR = 13.2) relative to Whites, but significantly lower in Asians (OR = 0.12). Above-average household income was protective for all categories of CF. CFS-like subjects reported more symptoms and were more severely disabled than ICF-like subjects, but the pattern of symptoms experienced by both groups was similar. In conclusion, unexplained chronic fatigue, including CFS-like illness, occurs in all sociodemographic groups, but may be most prevalent among persons with lower incomes and in some racial minorities. Future studies that include clinical evaluation of incident cases of CFS and ICF are required to further clarify the epidemiology of unexplained chronic fatigue in the population. ^

Design and evaluation of the parent education component of a comprehensive violence prevention project in middle schools

Low parental monitoring is related to youth risk behaviors such as delinquency and aggression. The purpose of this dissertation was to describe the development and evaluation of a parent education intervention to increase parental monitoring in Hispanic parents of middle school children.^ The first study described the process of intervention mapping as used to develop Padres Trabajando por la Paz, a newsletter intervention for parents. Using theory, empirical literature, and information from the target population, performance objectives and determinants for monitoring were defined. Learning objectives were specified and a staged social-cognitive approach was used to develop methods and strategies delivered through newsletters.^ The second study examined the outcomes of a randomized trial of the newsletter intervention. Outcome measures consisted of a general measure of monitoring, parent and child reports of monitoring behaviors targeted by the intervention, and psychosocial determinants of monitoring (self-efficacy, norms, outcome expectancies, knowledge, and beliefs). Seventy-seven parents completed the randomized trial, half of which received four newsletters over an eight-week period. Results revealed a significant interaction effect for baseline and treatment for parent's reports of norms for monitoring (p =.009). Parents in the experimental condition who scored low at baseline reported increased norms for monitoring at follow-up. A significant interaction effect for child reports of parental monitoring behaviors (p =.04) reflected an small increase across baseline levels in the experimental condition and decreases for the control condition at higher baseline scores. Both groups of parents reported increased levels of monitoring at follow-up. No other outcome measures varied significantly by condition.^ The third study examined the relationship between the psychosocial determinants of parental monitoring and parental monitoring behaviors in the study population. Weak evidence for a relationship between outcome expectancies and parental monitoring behaviors suggests further research in the area utilizing stronger empirical models such as longitudinal design and structural equation modeling.^ The low-cost, minimal newsletter intervention showed promise for changing norms among Hispanic parents for parental monitoring. In light of the importance of parental monitoring as a protective factor for youth health risk behaviors, more research needs to be done to develop and evaluate interventions to increase parental monitoring. ^

An investigation of the pica practices of pregnant women in Houston and Prairie View, Texas

Pregnant African American women are at higher risk of having a preterm delivery and/or a low birthweight infant. Many factors are associated with adverse pregnancy outcomes but a food habit that deserves further study in the causal process is pica, a craving for, and ingestion of, nonnutritive substances such as laundry starch, clay, dirt, or ice. This food habit is more common in the African American population but has not been adequately studied in relation to preterm and/or low birth weight infants.^ Mothers (n = 281) with infants less than one year of age who participated in the Special Supplementary Food Program for Women, Infants, and Children (WIC) at clinics in Houston and Prairie View, Texas were interviewed regarding pica practices during pregnancy, dietary practices, and some demographic indices. Hospital records were abstracted for health information on the mothers and infants, including birthweight and gestational age at birth of the infant.^ The subjects were 88.6% African American, 6.8% Hispanic, and 4.6% Caucasian. Overall prevalence of pica was 76.5%. Pica prevalence by substance(s) was as follows: ice 53.7%; ice and freezer frost 14.6%; other substances such as baking soda, baking powder, cornstarch, laundry starch, and clay or dirt 8.2%; and 23.5% reported no pica. The women who reported ice/freezer frost pica had a higher percentage of illegal drug use and alcohol use during pregnancy. The women who reported other pica substances had the lowest mean educational level, highest gravidity, and a higher percentage smoked during pregnancy.^ There were no significant differences in nutrient intakes measured by the mean 24-hour dietary recalls between women who reported ice pica (n = 103) and women who denied pica (n = 50). The women who reported ice/freezer frost pica or other pica substances had more food cravings and food dislikes during pregnancy than those who reported ice pica or no pica.^ There were no differences in mean birthweight or mean gestational age at birth of infants born to mothers from the three pica groups and the no pica group but regression analyses revealed a possible relationship between pica, low maternal hemoglobin at delivery, and preterm birth. ^

Status epilepticus and multiple organ system dysfunction

Recent reports have suggested the possible association of status epilepticus and multiple organ system failure. The purpose of this case control study was to investigate this association and to identify factors that predispose individuals with status epilepticus (SE) or aborted status epilepticus (ASE) to develop multiple organ system failure (MOSF) or multiple organ system dysfunction (MODS).^ For the purpose of the study, definitions of SE, ASE, MOSF, and MODS were operationalized as follows: SE was defined as any seizure lasting for a duration of $\ge$30 minutes or intermittent seizures lasting for $\ge$30 minutes from which the patient does not regain consciousness. ASE was defined as any seizure lasting for a duration of $\ge$10 minutes but $<$30 minutes and which was aborted as a result of a medical intervention. MOSF was defined as the failure of $\ge$2 organ systems in the same patient; organ system failure was said to be present whenever standard MOSF criteria were met. MODS was defined as the dysfunction of $\ge$2 organ systems in the same patient; organ system dysfunction was said to be present, whenever the monitor(s) of that organ's function exceeded the normal range for the physiological or laboratory parameters.^ Medical records of 686 individuals between the age of 5 and 44 years, with history of seizures needing hospitalization at the Texas Children's Hospital or Methodist Hospital, Houston, Texas, between 1991-95 were reviewed and 100 individuals with SE/ASE were identified. Of these 100 individuals with SE/ASE, 45 developed MOSF/MODS during their hospitalization and 9 of these individuals died. Using multivariate analyses, it was found that adult individuals who had an "acute" etiology of their seizure disorder (OR = 5.23; 95%CI: 0.41, 66.24) and children who had a "remote" etiology of their seizure disorder (OR = 3.92; 95%CI: 0.53, 29.22), were more likely to develop MOSF/MODS compared with those who had other etiologies of the seizure disorder. Individuals with SE lasting more than one hour were more likely to develop MOSF/MODS compared with individuals with SE lasting less than 1 hour (OR = 6.51; 95%CI: 1.63, 25.92). Individuals who presented with the SE/ASE episode as their first seizure episode were more likely to develop MOSF/MODS compared to those with a previous history of seizure episodes (OR = 1.78; 95%CI: 0.36, 8.82).^ The major limitations of this study includes the relatively small sample size and the study being performed in only two institutions. However, this is the first study of this kind and should therefore be viewed as largely exploratory in nature. Future studies should investigate the relationship of the risk factors identified in this study using a larger number of institutions and patients. ^

AIDS talk

The observations of Michel Foucault, noted Twentieth Century French philosopher, regarding modern power relations and orders of discourse, form the framework utilized to analyze and interpret the power struggles of AIDS activists and their opponents--the religious and radical right, and the administrative agencies of the 'Liberal' welfare State. Supported by the tools of sociolinguistic inquiry, the analysis highlights the success of a safer sex campaign in Houston, Texas to illustrate the dynamics of cultural and political change by means of discursive transformations initiated by the gay micro-culture. The KS/AIDS Foundation, allied with both the biomedical community and gay entertainment spheres, was successful in conveying biomedical cautions that resulted in altered personal behavior and modified public attitudes by using linguistic conventions consonant with the discourse of the Houston gay micro-culture. The transformation of discursive practices transgressed not only the Houston gay micro-culture's boundaries, but the city boundaries of Houston as well. In addition to cultural and political change, moderate and confrontational gay activists also sought to change the cognitive boundaries surrounding 'the gold standard' for clinical research trials.^ From a Foucauldian perspective, the same-sex community evolved from the subordinated Other to a position of power in a period of five years. Transformations in discursive practices and power relations are exemplified by the changing definitions employed by AIDS policy-makers, the public validation of community-based research and the establishment of parallel track drug studies. Finally, transformations in discursive practices surrounding the issues of HIV antibody testing are interpreted using Foucault's six points of power relations. The Montrose Clinic provides the case study for this investigation. The clinic turned the technical rationalities of the State against itself to achieve its own ends and those of the gay micro-culture--anonymous testing with pre and post test counseling. AIDS Talk portrays a dramatic transformation in discursive practices and power relations that transcends the historical moment to provide a model for future activists. Volume 2 contains copies of fugitive primary source materials largely unavailable elsewhere. Original documents are archived in the Harris County Medical Archives in the Houston Academy of Medicine located in the Texas Medical Center Library, Houston, Texas. ^

Contribution of the genes of the renin-angiotensin system to interindividual differences in blood pressure levels in Caucasians from Rochester, Minnesota

The Renin-Angiotensin system (RAS) regulates blood pressure through its effects on vascular tone, renal hemodynamics, and renal sodium and fluid balance. The genes encoding the four major components of the RAS, angiotensinogen, renin, angiotensin I-converting enzyme (ACE), and angiotensin II receptor type 1 (AT1), have been investigated as candidate genes in the pathogenesis of essential hypertension. However, studies have primarily focused on small samples of diseased individuals, and, therefore, have provided little information about the determinants of interindividual variation in blood pressure (BP) in the general population.^ Using data from a large population-based sample from Rochester, MN, I have evaluated the contribution of variation in the region of the RAS genes to interindividual variation in systolic, diastolic, and mean arterial pressure in the population-at-large. Marker genotype data from four polymorphisms located within or very near these genes were first collected on 3,974 individuals from 583 randomly ascertained three-generation pedigrees. Haseman-Elston regression and variance component methods of linkage analysis were then carried out to estimate the proportion of interindividual variance in BP attributable to the effects of variation at these four measured loci.^ A significant effect of the ACE locus on interindividual variation in mean arterial pressure (MAP) was detected in a sample of siblings belonging to the youngest generation. After allowing for measured covariates, this effect accounted for 15-25% of the interindividual variance in MAP, and was even greater in a subset with a positive family history of hypertension. When gender-specific analyses were carried out, this effect was significant in males but not in females. Extended pedigree analyses also provided evidence for an effect of the ACE locus on interindividual variation in MAP, but no difference between males and females was observed. Circumstantial evidence suggests that the ACE gene itself may be responsible for the observed effects on BP, although the possibility that other genes in the region may be at play cannot be excluded.^ No definitive evidence for an effect of the renin, angiotensinogen, or AT1 loci on interindividual variation in BP was obtained in this study, suggesting that the impact of these genes on BP may not be great in the Caucasian population-at-large. However, this does not preclude a larger effect of these genes in some subsets of individuals, especially among those with clinically manifest hypertension or coronary heart disease, or in other populations. ^

Patterns of care and outcomes for pregnant inmates and their infants in Texas state prisons: Epidemiologic and ethnographic analyses

Female inmates make up the fastest growing segment in our criminal justice system today. The rapidly increasing trend for female prisoners calls for enhanced efforts to strategically plan the correctional facilities that address the needs of this growing population, and to work with communities to prevent crime in women. The incarcerated women in the U.S. have an estimated 145,000 minor children who are predisposed to unique psychosocial problems as a result of parental incarceration.^ This study examined the patterns of care and outcomes for pregnant inmates and their infants in Texas state prisons between 1994 and 1996. The study population consists of 202 pregnant inmates who delivered in a 2-year period, and a randomly sampled comparison cohort of 804 women from general Texas population, matched on race and educational levels. Both quantitative and qualitative data were used to elucidate the inmates' risk-factor profile, delivery/birth outcomes, and the patterns of care during pregnancy. The continuity-of-care issues for this population were also explored.^ Epidemiologic data were derived from multiple record systems to establish the comparison between two cohorts. A significantly great proportion of the inmates have prior lifestyle risk-factors (smoking, alcohol, and illicit drug abuse), poorer health status, and worse medical history. However, most of these existing risk-factors seem to show little manifestation in their current pregnancy. On the basis of maternal labor/delivery outcome and a number of neonatal indicators, this study found some evidence of a better pregnancy outcome for the inmate cohort when compared to the comparison group. Some possible explanations of this paradox were discussed. Seventeen percent of inmates gave birth to infants with suspected congenital syphilis. The placement patterns for the infants' care immediately after birth were elucidated.^ In addition to the quantitative data, an ethnographic approach was used to collect qualitative data from a subset of the inmate cohort (n = 20) and 12 care providers. The qualitative data were analyzed for their contents and themes, giving rise to a detailed description of the inmates' pregnancy experience. Eleven themes emerged from the study's thematic analysis, which provides the context for interpreting the epidemiologic data.^ Meaningful findings in this study were presented in a three-dimensional matrix to shed light on the apparent relationship between outcome indicators and their potential determinants. The suspected "linkages" between the outcome and their determinants can be used to generate hypotheses for future studies. ^

Evaluation of androgenicity, abdominal adiposity, blood pressure and types of ovulatory patterns in a sample of women with menstrual irregularities

Objective: To determine the prevalence of and the relationships between the degree and source of hyperandrogenemia, ovulatory patterns and cardiovascular disease risk indicators (blood pressure, indices or amount of obesity and fat distribution) in women with menstrual irregularities seen at endocrinologists' clinic. Design: A cross-sectional study design. Participants: A sample of 159 women with menstrual irregularities, aged 15-44, seen at endocrinologists' clinic. Main Outcome Measures: androgen levels, body mass index (BMI), waist-hip ratio (WHR), systolic and diastolic blood pressure (SBP & DBP), source of androgens, ovulatory activity. Results: The prevalence of hyperandrogenemia was 54.7% in this study sample. As expected, women with acne or hirsutism had an odds ratio 12.5 (95%CI = 5.2-25.5) times and 36 (95%CI = 12.9-99.5) times more likely to have hyperandrogenemia than those without acne or hirsutism. The main findings of this study were the following: Hyperandrogenemic women were more likely to have oligomenorrheic cycles (OR = 3.8, 95%CI = 1.5-9.9), anovulatory cycles (OR = 6.6, 95%CI = 2.8-15.4), general obesity (BMI $\ge$ 27) (OR = 6.8, 95%CI = 2.2-27.2) and central obesity (WHR $\ge$ 127) (OR = 14.5, 95%CI = 6.1-38.7) than euandrogenemic women. Hyperandrogenemic women with non-suppressible androgens had a higher mean BMI (29.3 $\pm$ 8.9) than those with suppressible androgens (27.9 $\pm$ 7.9); the converse was true for abdominal adiposity (WHR). Hyperandrogenemic women had a 2.4 odds ratio (95%CI = 1.0-6.2) for an elevated SBP and a 2.7 odds ratio (95%CI = 0.8-8.8) for elevated DBP. When age differences were accounted for, this relationship was strengthened and further strengthened when sources of androgens were controlled. When the differences in BMI were controlled, the odds ratio for elevated SBP in hyperandrogenemic women increased to 8.8 (95%CI = 1.1-69.9). When the age, the source of androgens, the amount of obesity and the type of obesity were controlled, hyperandrogenemic women had 13.5 (95%CI = 1.1-158.9) odds ratio for elevated SBP. Conclusions: In this study population, the presence of menstrual irregularities are highly predictive for the presence of elevated androgens. Women with elevated androgens have a high risk for obesity, more specifically for central obesity. The androgenemic status is an independent predictor of blood pressure elevation. It is probable that in the general population, the presence of menstrual irregularities are predictive of hyperandrogenemia. There is a great need for a population study of the prevalence of hyperandrogenemia and for longitudinal studies in hyperandrogenemic women (adrenarche to menopause) to investigate the evolution of these relationships. ^

Survey of safety climate in public hospitals in Costa Rica in 1997

In response to growing concern for occupational health and safety in the public hospital system in Costa Rica, a research program was initiated in 1995 to evaluate and improve the safety climate in the national healthcare system through regional training programs, and to develop the capacity of the occupational health commissions in these settings to improve the identification and mitigation of workplace risks. A cross-sectional survey of 1000 hospital-based healthcare workers was conducted in 1997 to collect baseline data that will be used to develop appropriate worker training programs in occupational health. The objectives of this survey were to: (1) describe the safety climate within the national hospital system, (2) identify factors associated with safety climate focusing on individual and organizational variables, and (3) to evaluate the relationship between safety climate and workplace injuries and safety practices of employees. Individual factors evaluated included the demographic variables of age, gender, education and profession. Organizational factors evaluated included training, psychosocial work environment, job-task demands, availability of protective equipment and administrative controls. Work-related injuries and safety practices of employees included the type and frequency of injuries experienced and reported, and compliance with established safety practices. Multivariate regression analyses demonstrated that training and administrative controls were the two most significant predictors of safety climate. None of the demographic variables were significant predictors of safety climate. Safety climate was inversely and significantly associated with workplace injuries and positively and significantly associated with safety practices. These results suggest that training and administrative controls should be included in future training efforts and that improving safety climate will decrease workplace injuries and increase safety practices. ^

The association of genetic groups 1, 2, and 3 of Mycobacterium tuberculosis with pulmonary and extra-pulmonary tuberculosis

Objective. To investigate the association of the three major genetic groups of Mycobacterium tuberculosis with pulmonary and extra-pulmonary tuberculosis in clustered and non-clustered TB cases in the Houston area. ^ Study design. Secondary analysis of an ambi-directional study. ^ Study population. Three hundred fifty-eight confirmed cases of tuberculosis in the Houston that occurred between October 1995 and May 1997, who had been interviewed by the Houston T13 Initiative staff at Baylor College of Medicine, and whose isolates have had their DNA fingerprint and genetic group determined. ^ Exclusions. Individuals whose mycobacterial genotype was unknown, or whose data variables were unavailable. ^ Source of data. Laboratory results, patient interviews, and medical records at clinics and hospitals of the study population. ^ Results. In clustered cases, the majority of both, pulmonary and extra-pulmonary TB cases were caused by genetic group 1. Independent factors were assessed to determine the interactions that may influence the site of infection or increase the risk for one site or another. HIV negative males were protected against extra-pulmonary TB compared to HIV negative females. Individuals ages 1–14 years were at higher risk of having extra-pulmonary TB. Group 3 organisms were found less frequently in the total population in general, especially in extra-pulmonary disease. This supports the evidence in previous studies that this group is the least virulent and genetically distinct from the other two groups. Group 1 was found more frequently among African Americans than other ethnic groups, a trend for future investigations. ^ Among the non-clustered cases, group 2 organisms were the majority of the organisms found in both sites. They were also the majority of organisms found in African Americans, Caucasians, and Hispanics causing the majority of the infections at both sites. However, group 1 organisms were the overwhelming majority found in Asian/Pacific Islander individuals, which may indicate these organisms are either endemic to that area, or that there is an ethnic biological factor involved. This may also be due to a systematic bias, since isolates from individuals from that geographic region lack adequate copies of the insertion sequence IS6110, which leads to their placement in the non-clustered population. ^ The three genetic groups of Mycobacterium tuberculosis were not found equally distributed between sites of infection in both clustered and non-clustered cases. Furthermore, these groups were not distributed in the same patterns among the clustered and non-clustered cases, but rather in distinct patterns. ^

Physical activity and survival after a first myocardial infarction: The Corpus Christi Heart Project

Previous studies have demonstrated that habitual physical activity is associated with a reduced risk of incident coronary heart disease (CHD). However, the role of physical activity in lowering the risk of all-cause mortality, CHD mortality, reinfarction, or receipt of a revascularization procedure after a first myocardial infarction (MI) remains unresolved, particularly in minority populations. To investigate the associations between physical activity and risk of all-cause mortality, CHD mortality, reinfarction, and receipt of a revascularization procedure, this study was conducted among Mexican-American and non-Hispanic white women and men who survived a first MI. The Corpus Christi Heart Project, a population-based cardiovascular surveillance study, provide data which included vital status, survival time, medical history, CHD risk factor information, including level of physical activity among Mexican-American and non-Hispanic white adults who had experienced a first MI between May, 1988 and April, 1990. MI patients were interviewed at baseline and annually thereafter until their death or through May, 1995. A categorical variable was created to reflect change in level of physical activity following the first MI; categories included (1) sedentary with no change, (2) decreased activity, (3) increased activity, and (4) moderate activity with no change (the referent group). Proportional hazards regression analyses were used to assess the relationship of level of physical activity and risk of death, reinfarction, or receipt of a revascularization procedure adjusting for age, sex, ethnicity, severity of MI, and CHD risk factor status. Over a 7-year follow-up period, the relative risk (95% confidence intervals) of all-cause mortality was 4.67 (2.27, 9.60) for the sedentary-no change group, 2.33 (0.96, 5.67) for the decreased activity group, and 0.52 (0.11, 2.41) for the increased activity group. The relative risk of CHD mortality was 6.92 (2.05, 23.34) for the sedentary-no change group, 2.40 (0.55, 10.51) for the decreased activity group, and 1.58 (0.26, 9.65) for the increased activity group. The relative risk for reinfarction was 2.50 (1.52, 4.10) for the sedentary-no change group, 2.26 (1.24, 4.12) for the decreased activity group, and 0.52 (0.21, 1.32) for the increased activity group. Finally, the relative risk for receipt of a revascularization procedure was 0.65 (0.39, 1.07) for the sedentary-no change group, 0.45 (0.22, 0.92) for the decreased activity group, and 1.01 (0.51, 2.02) for the increased activity group. No interactions were observed for ethnicity or severity of first MI. These results are consistent with the hypothesis that moderate physical activity is independently associated with a lower risk of all-cause mortality, CHD mortality, and reinfarction, but not revascularization, among Mexican-American and non-Hispanic white, female and male, first MI patients. These results also support the current recommendation that physical activity plays an important role in the secondary prevention of CHD. ^

Sequential updating via dynamic hierarchical models: A Bayesian approach to longitudinal data analysis

Most statistical analysis, theory and practice, is concerned with static models; models with a proposed set of parameters whose values are fixed across observational units. Static models implicitly assume that the quantified relationships remain the same across the design space of the data. While this is reasonable under many circumstances this can be a dangerous assumption when dealing with sequentially ordered data. The mere passage of time always brings fresh considerations and the interrelationships among parameters, or subsets of parameters, may need to be continually revised. ^ When data are gathered sequentially dynamic interim monitoring may be useful as new subject-specific parameters are introduced with each new observational unit. Sequential imputation via dynamic hierarchical models is an efficient strategy for handling missing data and analyzing longitudinal studies. Dynamic conditional independence models offers a flexible framework that exploits the Bayesian updating scheme for capturing the evolution of both the population and individual effects over time. While static models often describe aggregate information well they often do not reflect conflicts in the information at the individual level. Dynamic models prove advantageous over static models in capturing both individual and aggregate trends. Computations for such models can be carried out via the Gibbs sampler. An application using a small sample repeated measures normally distributed growth curve data is presented. ^