Prevalence and trends of substance abuse in Harris County, Texas, 1989 to 1991

In the late 1980s, Harris County, Texas began experiencing an escalation of drug-related activities. Various indicators used in this analysis tracked drug-related trends from 1989 to 1991 to determine patterns for comparison of local (Houston/Harris County, Texas) to national levels.^ An important indicator of the drug scenario was drug-related activities among youths, which increased during the period of this study. The Harris County Juvenile Probation Department showed that among arrests for drug-related activities, felonies increased from 25% in 1988 to 53% in 1991. With the rise in drug-related crimes, and substance abuse among the student body, school districts were forced to institute drug education programs in an effort to curtail such activities.^ Law enforcement agencies in the county saw increased demands for their services as a result of drug activities. Harris County Sheriffs Department reported a 32% plus increase in drug-related charges between 1986 and 1991. Houston Police Department reported an increase of 109% for the same period.^ Data from the Harris County Medical Examiner, the National Institute of Justice's Drug Use Forecasting System (Houston), and drug treatment facilities around Houston/Harris County, Texas indicated similar drug usage trends. Over a four-year period (1988-91), the drugs most frequently detected during blood and urine analyses were cocaine, followed by marijuana, heroin, LSD, and methamphetamines.^ From 1988 to 1991, most drug rehabilitation organizations experienced increased demands for their services by approximately 35%. Several other organizations experienced as much as a 70 percent increase. Males accounted for roughly 70% and females about 30% of persons seeking treatment. However, the number of females pursuing treatment increased, thereby reducing the gender gap.^ Blacks in Houston/Harris County were at higher risk for drug usage among the general population, but sought treatment more readily than other ethnic groups. Whites sought treatment in similar numbers as Blacks, but overall the risk appeared smaller because they made up a larger portion of the Houston/Harris County population.^ This analysis concluded that drug trends for the Houston/Harris County, Texas did not follow national trends, but showed patterns of its own. It was recommended that other communities carry out similar studies to determine drug use trends particular to their local. ^

Infectious diseases, immune status, and health insurance among child care providers in Houston, Texas

The objectives of this study were to compare female child-care providers with female university workers and with mothers of children in child-care centers for: (1) frequency of illness and work loss days due to infectious diseases, (2) prevalence of antibodies against measles, rubella, mumps, hepatitis B, hepatitis A, chickenpox and cytomegalovirus (CMV), and (3) status regarding health insurance and job benefits.^ Subjects from twenty child-care centers and twenty randomly selected departments of a university in Houston, Texas were studied in a cross-sectional fashion.^ A cluster sample of 281 female child-care providers from randomly selected child-care centers, a cluster sample of 286 university workers from randomly selected departments and a systematic sample of 198 mothers of children from randomly selected child-care centers.^ Main outcome measures were: (1) self-reported frequency of infectious diseases and number of work-days lost due to infectious diseases; (2) presence of antibodies in blood; and (3) self-reported health insurance and job benefits.^ In comparison to university workers, child-care providers reported a higher prevalence of infectious diseases in the past 30 days; lost three times more work-days due to infectious diseases; and were more likely to have anti-core antibodies against hepatitis B (odds ratio = 3.16 95% CI 1.27-7.85) and rubella (OR 1.88, 95% CI 1.02-3.45). Child-care providers had less health insurance and job-related benefits than mothers of children attending child-care centers.^ Regulations designed to reduce transmission of vaccine and non-vaccine preventable diseases in child-care centers should be strictly enforced. In addition policies to improve health insurance and job benefits of child-care providers are urgently needed. ^

Impact of environmental regulations on lead concentrations in Texas ambient air and water: 1970--1990

In the last two decades, the significance of lead has been addressed in a number of environmental regulations at the national and state levels. This project investigated the environmental regulations (Clean Air Act and Amendments, 1970-1990 and Clean Water Act of 1977) and their cumulative effects on lead in ambient air and water in the state of Texas. For this purpose, historical records from the Texas Water Development Board, Texas Natural Resources Conservation Commission, and the United States Geological Survey have been assembled and analyzed for temporal and spatial trends. These trends might correspond to the phase out of lead in gasoline and other regulations.^ This study concluded that there is a significant correlation (p $\leq$.001) between environmental regulations of lead in gasoline and the concentration of lead in ambient air. Lead concentrations in ambient air have been reduced by over 90 percent in the past twenty years. An overall significant difference (p $\leq$.001) was found in mean (94, 15 respectively) lead concentrations in surface water between two time periods, one at the beginning of the twenty year period and one at the end of the study period. There has been an overall reduction of lead concentrations in surface water in Texas of approximately 84 percent. However, this reduction cannot be statistically associated with any one regulation. Groundwater data could not be analyzed for lead concentrations because of limitations of reporting data as "less than". Approximately two percent of the groundwater data was analyzed by Oneway ANOVA and no significant difference was found between the means (18, 19 respectively) of two time periods, 1977-1979 and 1988-1990. This data is consistent with the regulations having a contributory affect on declining concentrations, but other factors cannot be ruled out as having added to these declines. This study can also serve as a starting point for a more in-depth study of environmental regulations and their impact on the environment. ^

Liberation of hope: An ethnographic study of community-based initiatives in Houston, Texas

This is an ethnographic study about the worldview of community-based initiatives in Houston, Texas, and the people who work in them. People who participated in this study recognize that their direct constructive action is at the heart of authentic social change in their minority communities. Through qualitative data analysis, a constellation of relationships and process patterns were found to constitute themselves into the system of the community-based initiative. The predominant patterns identified from the findings in this study are: the pervasiveness of place, the importance of people, unique initiatory patterns, the concrete local sustainability, the ever-present action orientation, the resourceful use of networks and inter-relationships, the significance of church influence, the core sense of spirituality and the essence of hope. These patterns emerged out of the local knowledge, which is acutely sensitive to the elements of history and lived experience, embedded in the distinctive moral and visionary patterns of meaning and expression. Findings from the research reveal that these community-based initiatives are not programs--they are people--people who keep hope alive in their communities and who, by their daily practice, liberate others. ^

Process and outcome evaluation of the hepatitis B perinatal vaccination program in Houston, Texas, 1991--1993

A retrospective cohort study was designed to evaluate the compliance of vaccination dose schedules and vaccination effectiveness at 12 months of age among a total of 226 high-risk infants born to HBsAg-positive pregnant women who participated in the HBV Perinatal Vaccination Program in Houston, Texas, 1991-1993.^ The seroprevalence of HBsAg-positivity was 0.5% among pregnant women who attended prenatal clinics in Houston, Texas, 1991-1993. The Asian women had the highest seroprevalence rate (5.9%), followed by black (1.9%), white (0.7%), and Hispanic women (0.3%). The seroprevalence of HBsAg increased with age (p =.02); the highest seroprevalence rate found among the $>$40 group (5.4%), followed by the 20-40 age group, and the $<$20 age. A steady increase was observed in the number of infants, from 45 in 1991, to 103 in 1993. The majority of these infants were black (58.0%), followed by Hispanic (28.8%), Asian (8.4%), and white infants (4.0%). Significant increases were observed from 1991 to 1993 in the number of infants who initiated vaccination (86.7% to 98.1%, p =.02) and in those infants who were post-tested at 12 months of age (24.4% to 44.7%, p =.04). During the same period an increase was also observed in the number of infants who completed the vaccination dose schedules (62.2% to 72.8%, p =.37). The compliance rates were not statistically significant regarding gender, race or ethnicity, health service area, medical referral source, and residential geographic areas. About 56.0% of the reasons cited for non-compliance among the 144 infants who neither completed the vaccination dose schedules nor received the 12-month post-test were "moved," and "no response/not at home." A total of 82 infants completed the vaccination dose schedules and were post-tested at 12 months of age for anti-HBs-positivity, and 96.3% of these infants seroconverted. A race-specific statistically significant seroconversion difference was found among infants who received all vaccination doses and were post-tested at 12 months of age (100% for the black and the white, 96.3% for the Hispanic, and 80.0% for the Asians infants, p =.05).^ From a public health perspective, the HBV Perinatal Vaccination Program improved during its first three years (1991-1993). It was effective in preventing perinatal HBV infection in almost 97.0% of infants who were vaccinated and post-tested. To increase the efficiency and efficacy of the program, the following recommendations are proposed: (1) Increase the vaccination compliance rate by educating and improving the tracking, communication and coordination channels with those individuals involved in the process and by increasing staff resources. (2) Reduce the post-test vaccination non-compliance by post-testing infants simultaneously with third vaccination dose at 6 months of age, and only post-test those infants who are anti-HBs-negative at 9-12 months of age. (Abstract shortened by UMI.) ^

Hispanic incorporation and access to health care in Houston and Harris County, Texas: Adopting an Hispanic perspective to the Aday and Andersen model

This study examines Hispanic levels of incorporation and access to health care. Applying the Aday and Andersen framework for the study of access, the study examined the relationship between two levels of Hispanic incorporation into U.S. society, i.e., mainstream versus ethnic, and potential and realized measures of access to health care. Data for the study were drawn from a 1992 telephone survey of 600 randomly selected Hispanics in Houston and Harris County.^ The hypotheses tested were: (1) Hispanics who are incorporated into mainstream society are more likely to have better potential and realized access to health care than those who are incorporated into ethnic-group enclaves regardless of their socioeconomic status (SES), health status and health needs, and (2) there is no interaction between the levels of incorporation (mainstream or ethnic) and SES, health status, and health needs in predicting potential and realized access.^ The data analysis supported Hypothesis One for the two measures of potential access. The results of bivariate and multiple logistic regression analyses indicated that for Hispanics in Houston and Harris County, being in the "mainstream" incorporation category increased their potential access to care, having "health insurance" and a "regular place of care". For the selected measure of realized access, having a "regular check-up", the analysis did not demonstrate statistically significant differences in having a regular check-up among Hispanics incorporated in the ethnic or mainstream incorporation categories.^ Hypothesis Two, that there is no interaction between the levels of incorporation and socioeconomic characteristics, health status, and health needs in predicting potential and realized access among Hispanics was supported by the data. The results of the logistic regression analysis showed that, after adjusting for socioeconomic status, health status, and health needs, the association between "level of incorporation" and the two measures of potential access ("health insurance" and having a "usual place of care") was not modified by the control variables nor by their interaction with level of incorporation. That is, the effect of incorporation on Hispanics' health insurance coverage, and having a usual place of care, was homogenous across Hispanics with different SES and health status.^ The main research implication of this dissertation is the employment of a theoretical framework for the assessment of cultural factors essential to research on migrating heterogeneous subpopulations. It also provided strategies to solve practical and methodological difficulties in the secondary analyses of data on these populations. ^

The use of invasive myocardial revascularization procedures following myocardial infarction and the effectiveness of these procedures in the biethnic community of Nueces County, Texas, 1988--1991

High levels of poverty and unemployment, and low levels of health insurance coverage may pose barriers to obtaining cardiac care by Mexican Americans. We undertook this study to investigate differences in the use of invasive myocardial revascularization procedures received within the 4-month period following hospitalization for a myocardial infarction (MI) between Mexican Americans and non-Hispanic whites in the Corpus Christi Heart Project (CCHP). The CCHP is a population-based surveillance program for hospitalized MI, percutaneous transluminal coronary angioplasty (PTCA), and aortocoronary bypass surgery (ACBS). Medical record data were available for 1706 patients identified over a three-year period. Mexican Americans had significantly lower rates of receiving a PTCA following MI than non-Hispanic Whites (RR: 0.56, 95% CI: 0.44-0.70). No meaningful ethnic difference was seen in the rates of ACBS use. History of PTCA use appeared to interact with ethnicity. Among patients without a history of PTCA use, Mexican Americans were less likely to receive a PTCA than non-Hispanic whites (RR: 0.59; 95% CI: 0.46-0.76). Among patients with a history of PTCA use, however, Mexican Americans were more likely to receive a PTCA than non-Hispanic whites (RR: 1.47; 95% CI: 0.75-2.87).^ Differences in the effectiveness of a first-time PTCA and first-time ACBS between Mexican Americans and non-Hispanic whites in the CCHP were also investigated. Mexican Americans were more likely to receive a 2nd PTCA (RR: 1.56, 95% CI: 1.11-2.17) and suffer a subsequent MI (RR: 1.42, 95% CI: 1.03-1.96) following a first-time PTCA than non-Hispanic whites. No meaningful ethnic differences were found in the rates of death and rates of ACBS following a first-time PTCA. Also, no significant ethnic differences were found in the rates of any of the events following a first-time ACBS. After adjusting for potential demographic, socioeconomic, clinical and angiographic confounders using Cox regression analysis, Mexican Americans were still more likely to receive a 2nd PTCA (HR: 1.38; 95% CI: 0.99-1.93) following a first-time PTCA than non-Hispanic whites. A significant difference in the rates of a subsequent MI following a first-time PTCA persisted (HR: 1.39, 95% CI: 1.01-1.93). (Abstract shortened by UMI.) ^

Macular edema in Hispanics with non-insulin dependent diabetes mellitus in Starr County, Texas: Prevalence, incidence and risk factors

This project is based on secondary analyses of data collected in Starr County, Texas from 1981 till 1991 to determine the prevalence, incidence and risk factors for macular edema in Hispanics with non-insulin-dependent diabetes in Starr County, Texas. Two studies were conducted. The first study examined the prevalence of macular edema in this population. Of the 310 diabetics that were included in the study 22 had macular edema. Of these 22 individuals 9 had clinically significant macular edema. Fasting blood glucose was found to be significantly associated with macular edema. For each 10 mg/dl increase in fasting blood glucose there was a 1.07 probability of an increase in the risk of having macular edema. Individuals with fasting blood glucose $\ge$200 mg/dl were found to be more than three times at risk of having macular edema compared to those with fasting blood glucose $<$200 mg/dl.^ In the second study the incidence and the risk factors that could cause macular edema in this Hispanic population were examined. 240 Hispanics with non-insulin-dependent diabetes mellitus and without macular edema were followed for 1223 person-years. During the follow-up period 27 individuals developed macular edema (2.21/100 person-years). High fasting blood glucose and glycosylated hemoglobin were found to be strong and independent risk factors for macular edema. Participants taking insulin were 3.9 times more at risk of developing macular edema compared to those not taking insulin. Systolic blood pressure was significantly related to macular edema, where each 10 mmHg increase in systolic blood pressure was associated with a 1.3 increase in the risk of macular edema.^ In summary, this study suggests that hyperglycemia is the main underlying factor for retinal pathological changes in this diabetic population, and that macular edema probably is not the result of sudden change in the blood glucose level. It also determined that changes in blood pressure, particularly systolic blood pressure, could trigger the development of macular edema.^ Based on the prevalence reported in this study, it is estimated that 35,500 Hispanic diabetics in the US have macular edema. This imposes a major public health challenge particularly in areas with high concentration of Mexican Americans. It also highlights the importance of public health measures directed to Mexican Americans such as health education, improved access to medical care, and periodic and careful ophthalmologic examination by ophthalmologists knowledgeable and experienced in the management of diabetic macular edema. ^

A GENETIC MARKER STUDY OF NON - INSULIN DEPENDENT DIABETICS IN THE MEXICAN-AMERICAN COMMUNITY FROM STARR COUNTY, TEXAS (PLASMA GLUCOSE, HEMOGLOBIN ANALYSIS)

Diabetes mellitus occurs in two forms, insulin-dependent (IDDM, formerly called juvenile type) and non-insulin dependent (NIDDM, formerly called adult type). Prevalence figures from around the world for NIDDM, show that all societies and all races are affected; although uncommon in some populations (.4%), it is common (10%) or very common (40%) in others (Tables 1 and 2).^ In Mexican-Americans in particular, the prevalence rates (7-10%) are intermediate to those in Caucasians (1-2%) and Amerindians (35%). Information about the distribution of the disease and identification of high risk groups for developing glucose intolerance or its vascular manifestations by the study of genetic markers will help to clarify and solve some of the problems from the public health and the genetic point of view.^ This research was designed to examine two general areas in relation to NIDDM. The first aims to determine the prevalence of polymorphic genetic markers in two groups distinguished by the presence or absence of diabetes and to observe if there are any genetic marker-disease association (univariate analysis using two by two tables and logistic regression to study the individual and joint effects of the different variables). The second deals with the effect of genetic differences on the variation in fasting plasma glucose and percent glycosylated hemoglobin (HbAl) (analysis of Covariance for each marker, using age and sex as covariates).^ The results from the first analysis were not statistically significant at the corrected p value of 0.003 given the number of tests that were performed. From the analysis of covariance of all the markers studied, only Duffy and Phosphoglucomutase were statistically significant but poor predictors, given that the amount they explain in terms of variation in glycosylated hemoglobin is very small.^ Trying to determine the polygenic component of chronic disease is not an easy task. This study confirms the fact that a larger and random or representative sample is needed to be able to detect differences in the prevalence of a marker for association studies and in the genetic contribution to the variation in glucose and glycosylated hemoglobin. The importance that ethnic homogeneity in the groups studied and standardization in the methodology will have on the results has been stressed. ^

LUNG CANCER AMONG TEXAS MALE OIL REFINERY WORKERS, 1976 - 1980 (CASE-CONTROL STUDY)

The apparent excess in the rate of lung cancer among the population of Texas coastal counties has prompted this study. The main objective was to assess the risk of lung cancer among employees of oil refining industries. Data collected by UTSPH and NCI were used for this research. A non significant overall low risk of lung cancer was observed among workers ever employed in oil refining (COR = 0.84). A lower but not significant risk of lung cancer was detected among the same workers when classified by their usual industry of employment (COR = 0.77). An overall non significant crosstime decline in the risk of lung cancer was observed among most of the occupational groups within the oil refining industry, with the exception of professional/technical and clerical/sales occupations where a non significant crosstime increase in the risk was observed. ^

A QUANTITATIVE INVESTIGATION OF SOURCE AND ELEMENTAL COMPOSITION OF INDOOR AND OUTDOOR FINE PARTICULATE AIR POLLUTION IN HOUSTON (TEXAS)

An investigation was undertaken to determine the chemical characterization of inhalable particulate matter in the Houston area, with special emphasis on source identification and apportionment of outdoor and indoor atmospheric aerosols using multivariate statistical analyses.^ Fine (<2.5 (mu)m) particle aerosol samples were collected by means of dichotomous samplers at two fixed site (Clear Lake and Sunnyside) ambient monitoring stations and one mobile monitoring van in the Houston area during June-October 1981 as part of the Houston Asthma Study. The mobile van allowed particulate sampling to take place both inside and outside of twelve homes.^ The samples collected for 12-h sampling on a 7 AM-7 PM and 7 PM-7 AM (CDT) schedule were analyzed for mass, trace elements, and two anions. Mass was determined gravimetrically. An energy-dispersive X-ray fluorescence (XRF) spectrometer was used for determination of elemental composition. Ion chromatography (IC) was used to determine sulfate and nitrate.^ Average chemical compositions of fine aerosol at each site were presented. Sulfate was found to be the largest single component in the fine fraction mass, comprising approximately 30% of the fine mass outdoors and 12% indoors, respectively.^ Principal components analysis (PCA) was applied to identify sources of aerosols and to assess the role of meteorological factors on the variation in particulate samples. The results suggested that meteorological parameters were not associated with sources of aerosol samples collected at these Houston sites.^ Source factor contributions to fine mass were calculated using a combination of PCA and stepwise multivariate regression analysis. It was found that much of the total fine mass was apparently contributed by sulfate-related aerosols. The average contributions to the fine mass coming from the sulfate-related aerosols were 56% of the Houston outdoor ambient fine particulate matter and 26% of the indoor fine particulate matter.^ Characterization of indoor aerosol in residential environments was compared with the results for outdoor aerosols. It was suggested that much of the indoor aerosol may be due to outdoor sources, but there may be important contributions from common indoor sources in the home environment such as smoking and gas cooking. ^