Secondary data analysis of lead screening compliance in high-risk children

Introduction. Despite the ban of lead-containing gasoline and paint, childhood lead poisoning remains a public health issue. Furthermore, a Medicaid-eligible child is 8 times more likely to have an elevated blood lead level (EBLL) than a non-Medicaid child, which is the primary reason for the early detection lead screening mandate for ages 12 and 24 months among the Medicaid population. Based on field observations, there was evidence that suggested a screening compliance issue. Objective. The purpose of this study was to analyze blood lead screening compliance in previously lead poisoned Medicaid children and test for an association between timely lead screening and timely childhood immunizations. The mean months between follow-up tests were also examined for a significant difference between the non-compliant and compliant lead screened children. Methods. Access to the surveillance data of all childhood lead poisoned cases in Bexar County was granted by the San Antonio Metropolitan Health District. A database was constructed and analyzed using descriptive statistics, logistic regression methods and non-parametric tests. Lead screening at 12 months of age was analyzed separately from lead screening at 24 months. The small portion of the population who were also related were included in one analysis and removed from a second analysis to check for significance. Gender, ethnicity, age of home, and having a sibling with an EBLL were ruled out as confounders for the association tests but ethnicity and age of home were adjusted in the nonparametric tests. Results. There was a strong significant association between lead screening compliance at 12 months and childhood immunization compliance, with or without including related children (p<0.00). However, there was no significant association between the two variables at the age of 24 months. Furthermore, there was no significant difference between the median of the mean months of follow-up blood tests among the non-compliant and compliant lead screened population for at the 12 month screening group but there was a significant difference at the 24 month screening group (p<0.01). Discussion. Descriptive statistics showed that 61% and 56% of the previously lead poisoned Medicaid population did not receive their 12 and 24 month mandated lead screening on time, respectively. This suggests that their elevated blood lead level may have been diagnosed earlier in their childhood. Furthermore, a child who is compliant with their lead screening at 12 months of age is 2.36 times more likely to also receive their childhood immunizations on time compared to a child who was not compliant with their 12 month screening. Even though there was no statistical significant association found for the 24 month group, the public health significance of a screening compliance issue is no less important. The Texas Medicaid program needs to enforce lead screening compliance because it is evident that there has been no monitoring system in place. Further recommendations include a need for an increased focus on parental education and the importance of taking their children for wellness exams on time.^

The relationship between calcium and fluoride intake, pregnancy and lactation and the risk of height loss in white women

This study was designed to investigate the effect of calcium and fluoride intake, and parity and lactation on the risk of spinal osteoporosis. Height loss was used as a surrogate measure for spinal fractures by taking advantage of documented changes in height found during the 25-year follow-up of the Charleston Heart Study cohort. Women who had lost 2-4" in height or who had no change in height during the follow-up period were defined as case and comparison subjects respectively. Calcium intake when the subjects were "about 25" and in the recent past, average intake of fluoride over 25 years, and parity and history of breastfeeding were ascertained by questionnaire from 54 case and 77 comparison subjects. Low calcium intake in the past decreased the risk of height loss (age-adjusted OR = 0.3, 95%CI: 0.1-0.96) although several potentially important confounding variables could not be adjusted for. There was no association between risk of height loss and present calcium intake (OR = 0.8, 95%CI: 0.3-2.6 for low versus high intake) after adjustment for past calcium intake. High fluoride intake decreased the risk of height loss (adjusted OR = 0.4, 95%CI: 0.1-1.2). The effect of fluoride or calcium intake in the present was modified by the level of the other nutrient. Compared to a low intake of both calcium and fluoride, a high intake of one increased the risk of height loss (crude OR = 3.3 for high fluoride/low calcium, crude OR = 6.0 for high calcium/low fluoride) although a high intake of both was slightly protective (crude OR = 0.7). It is estimated that a "high" nutrient intake in this population was greater than 850mg/day for calcium and 2mg/day for fluoride. After adjustment for age, increasing parity decreased the risk of height loss in women who had never breastfed (OR = 0.2, 95%CI: 0.01-1.7 for 4 or more children). Women who had breastfed were also at lower risk of height loss than nulliparous women (OR = 0.3, 95%CI: 0.1-1.2 for 4 or more children) although at any level of parity, breastfeeding women had a greater risk of height loss than did non-breastfeeding women. ^

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

The use of exercise electrocardiography (ECG) to detect latent coronary heart disease (CHD) is discouraged in apparently healthy populations because of low sensitivity. These recommendations however, are based on the efficacy of evaluation of ischemia (ST segment changes) with little regard for other measures of cardiac function that are available during exertion. 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 apparently healthy individuals. Study participants were 20,387 men (mean age = 42.2 years) and 6,234 women (mean age = 41.9 years) patients of a preventive medicine center in Dallas, TX examined between 1971 and 1989. During an average of 8.1 years of follow-up, there were 348 deaths in men and 66 deaths in women. In men, age-adjusted all-cause death rates (per 10,000 person years) across quartiles of maximal systolic blood pressure (SBP) (low to high) were: 18.2, 16.2, 23.8, and 24.6 (p for trend $<$0.001). Corresponding rates for maximal heart rate were: 28.9, 15.9, 18.4, and 15.1 (p trend $<$0.001). After adjustment for confounding variables including age, resting systolic pressure, serum cholesterol and glucose, body mass index, smoking status, physical fitness and family history of CVD, risks (and 95% 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. Similar 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). No associations were noted between maximal exercise rate-pressure product mortality. Similar results were seen for risk of CVD and CHD death. In women, similar trends in age-adjusted all-cause and CVD death rates across maximal SBP and heart rate categories were observed. Sensitivity of the exercise test in predicting mortality was enhanced when ECG results were evaluated together with maximal exercise SBP or heart rate with a concomitant decrease in specificity. Positive predictive values were not improved. The efficacy of the exercise test in predicting mortality in apparently healthy men and women was not enhanced by using maximal exercise hemodynamic responses. These results suggest that an exaggerated systolic blood pressure or an attenuated heart rate response to maximal exercise are risk factors for mortality in apparently healthy individuals. ^

Low birthweight and the risk of developing subsequent high blood pressure and/or dyslipidemia in childhood

The association between birthweight and blood pressure (BP), and birthweight and serum lipid concentrations at age 7 through 11 years was examined in 1446 black and white children. The prevalence ratio (with 95% confidence interval) for being in the race-, sex- and age-specific upper decile of diastolic BP in children born with low birthweight (LBW, $<$2500 grams) versus children with birthweight $\geq$2500 grams was for black boys, 2.66 (1.24-5.70). In the other race-sex groups for diastolic BP, and in all race-sex groups for systolic BP this ratio did not differ from one. Among white boys with LBW, but not in the other race-sex groups, higher than expected percentages of subjects were in the highest decile group of triglyceride concentrations (0.01 $<$ p $<$ 0.05). The prevalence ratio was 2.42 (1.19-4.91). When prematures were excluded only more than expected white girls with LBW were in the highest decile group of triglyceride concentrations. The prevalence ratio was 3.23 (1.16-9.00). Prevalence ratios for triglyceride concentrations in black boys and girls, and for LDL/HDL-C ratio, cholesterol and VLDL-C concentrations in all race-sex groups were not different from one in analyses including and in those excluding prematures. Mean triglyceride concentrations stratified by tertiles of Quetelet Index, race and sex showed a strongly positive association between triglyceride concentrations and Quetelet Index, and in the upper tertile of the Quetelet Index an association between LBW and raised triglyceride concentrations. Multiple linear regression analyses showed that after adjusting for sex, race and age present Quetelet Index (p $<$ 0.001) is a much stronger predictor of systolic and diastolic BP, and also of LDL-C/HDL-C ratio and triglyceride concentrations in this age group than birthweight (p $>$ 0.05). Thus, an association between LBW and subsequent risk for elevated BP was confirmed for diastolic BP in black boys, but not for the other race-sex groups, and not for systolic BP in any group. This is the first study finding an association between LBW and elevated triglyceride concentrations in boys (white and black) and girls (white). A follow-up study to assess whether the findings can be confirmed at adult age is recommended. ^

Ethnicity as a risk factor for diabetes incidence in a population of diagnosed hypertensives

Significant racial/ethnic differences exist in prevalence of hypertension (HTN) and non-insulin dependent diabetes mellitus (NIDDM). Hypertension is more common in diabetics than in non-diabetics, and an etiologic link between the two conditions has been proposed. Since there are few longitudinal studies of persons with both HTN and NIDDM, a retrospective cohort study was conducted to determine if ethnicity (Black, Hispanic (Mexican-American), and non-Hispanic White) was related to NIDDM incidence in a low-SES, multi-ethnic clinic population of diagnosed hypertensives. Two thousand nine hundred forty-one hypertensives free of NIDDM at baseline were followed for up to 10 years. Mean baseline age was 56 $\pm$ 12 years, M:F percent was 33:67, and Black:Hispanic:White percent was 63:17:20. There were 236 incident cases of NIDDM. In Cox proportional hazards analysis, the risk of developing NIDDM over 10 years was not related to ethnicity after controlling for significant covariates, including age, baseline blood glucose and body mass index (adjusted RR for Blacks compared to Whites =.82, 95 percent CI =.57-1.18; adjusted RR for Hispanics compared to Whites =.84, 95 percent CI =.51-1.38). This result contrasts with the increased risk of NIDDM among Blacks and Hispanics compared to Whites found in the general population. The study suggests that a diagnosis of hypertension equalizes the risk of developing NIDDM among the three ethnic groups. ^

Behavioral risk profile of marathon runners

Although long distance running clearly has benefits--as witnessed by its popularity--it also has risks of injury and death. Little is known, however, about the prevalence of potentially dangerous training habits in long distance runners, although anecdotal information suggests that many runners have erroneous beliefs about risks and benefits of marathon running. We conducted a cross-sectional survey to estimate the prevalence of 19 potentially dangerous training habits (risky behaviors) among marathon runners. A 66-item self-administered questionnaire was mailed to a stratified random sample of runners who finished of the 1992 Houston-Tenneco Marathon and were 21-71 years of age. Responses were obtained from 508 runners (83%) with approximately equal representation in four age-gender groups: men $<$40 years, men $\ge$40 years, women $<$40 years, and women $\ge$40 years.^ Prevalences of risky behaviors were high. 50% or more ran in dangerously hot and humid conditions, did not cool down or stretch after running, did not wear proper running gear, or ran when injured or ill; 25-49% did not warm up, ran on dangerous surfaces, did not drink sufficient water during training, increased weekly mileage too quickly, and ran during lightning storms; 10-24% ran daily, ran in areas with high pollution, ran in the same direction as traffic, did hard runs frequently, ran more than 60 miles per week, or ran against the advice of a physician.^ Positive associations were found between the practice of risky behaviors and self-reported prevalence of musculoskeletal injuries, heat-related injuries, noncompliance with recommendations for preventive health examinations, and noncompliance with positive health habits.^ These results indicate that many marathon runners engage in training habits that may increase risk of substantial injury or illness. Further studies are needed to explore the association of risky training behaviors on the incidence of injuries, and to determine reasons for noncompliance with recommendations from sports medicine specialists. ^

Cardiovascular diseases risk factors during the first year of life

The pattern of change in cardiovascular risk factors, blood pressure (SBP and DBP) and plasma total cholesterol (TC), over time, their tracking and their relation to anthropometric measurements during the first year of life were investigated. Also, the effect of breast feeding on TC and the relationship of blood pressure measurements and family history of CVD risk factors were examined. One hundred five newborn term, healthy infants who were seen at a pediatric clinic in The Woodlands, Texas were followed longitudinally from 2 weeks to 1 year of age. TC, blood pressure, weight and length of the infants were measured at age 2 weeks, and again at 2, 4, 6, 9 and 12 months. In addition, family history, maternal and paternal, of CVD risk factors was obtained. Data analyses included only 40 infants who completed one year of follow up.^ At 2 weeks of age, the median value for TC was 23 mg/dl higher for females than for males. This difference disappeared as infants got older. For males, most of the increase in TC median levels, from 114 to 137 mg/dl, occurred between the ages of 2 weeks and 2 months, whereas for the female group, TC levels increased moderately, about 10 mg/dl, between 9 and 12 months of age. Tracking of TC was examined by using Spearman's correlation analysis. There were strong correlations between measurements taken as early as 2 weeks of age with later measurements. These correlations were stronger and more significant for males than for females (for males, r varied between 0.51 to 0.70, whereas for females, r varied between 0.11 to 0.70). The association of body measurements with TC is no more than modest and is closer for female infants than for male infants. Analysis, also, showed that infants who received breast milk had a TC mean value 47 mg/dl higher than that for infants who received formula milk only during the period of breast feeding and this difference disappeared by age 12 months.^ In both genders, most of the increase in blood pressure (about 10-15 mmHg in both SBP and DBP) occurred during the first 4 months of life. Most of the increase for male infants occurred during the first 2 months of life, while for females, the increase in SBP and DBP was between the age of 2 and 4 months. Neither SBP nor DBP track well during the first year of life and most of the correlations between measurements at different ages were not significant for either gender. The cross-sectional relationship of blood pressure measurements and selected body measurements was assessed. For females, only at age of 12 months did DBP have positive and significant correlations with weight, length and Quetelet index (r = 0.57, 0.60 and 0.57, respectively). There were no significant correlations between blood pressure and body measurements for males. Finally, analysis showed that maternal history of CV risk factors was significantly related to SBP in the female infant group, but not for males. For DBP, neither maternal nor paternal history was related. ^

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. ^

THE RELATIONSHIP BETWEEN SERUM CHOLESTEROL AND CANCER INCIDENCE IN THE POPULATION OF THE HYPERTENSION DETECTION AND FOLLOW-UP PROGRAM

The relationship between serum cholesterol and cancer incidence was investigated in the population of the Hypertension Detection and Follow-up Program (HDFP). The HDFP was a multi-center trial designed to test the effectiveness of a stepped program of medication in reducing mortality associated with hypertension. Over 10,000 participants, ages 30-69, were followed with clinic and home visits for a minimum of five years. Cancer incidence was ascertained from existing study documents, which included hospitalization records, autopsy reports and death certificates. During the five years of follow-up, 286 new cancer cases were documented. The distribution of sites and total number of cases were similar to those predicted using rates from the Third National Cancer Survey. A non-fasting baseline serum cholesterol level was available for most participants. Age, sex, and race specific five-year cancer incidence rates were computed for each cholesterol quartile. Rates were also computed by smoking status, education status, and percent ideal weight quartiles. In addition, these and other factors were investigated with the use of the multiple logistic model.^ For all cancers combined, a significant inverse relationship existed between baseline serum cholesterol levels and cancer incidence. Previously documented associations between smoking, education and cancer were also demonstrated but did not account for the relationship between serum cholesterol and cancer. The relationship was more evident in males than females but this was felt to represent the different distribution of occurrence of specific cancer sites in the two sexes. The inverse relationship existed for all specific sites investigated (except breast) although a level of statistical significance was reached only for prostate carcinoma. Analyses after exclusion of cases diagnosed during the first two years of follow-up still yielded an inverse relationship. Life table analysis indicated that competing risks during the period of follow-up did not account for the existence of an inverse relationship. It is concluded that a weak inverse relationship does exist between serum cholesterol for many but not all cancer sites. This relationship is not due to confounding by other known cancer risk factors, competing risks or persons entering the study with undiagnosed cancer. Not enough information is available at the present time to determine whether this relationship is causal and further research is suggested. ^

THE RELATIONSHIP BETWEEN DEGREE OF BLOOD PRESSURE REDUCTION AND MORTALITY AMONG HYPERTENSIVES IN THE HYPERTENSION DETECTION AND FOLLOW-UP PROGRAM

The relationship between degree of diastolic blood pressure (DBP) reduction and mortality was examined among hypertensives, ages 30-69, in the Hypertension Detection and Follow-up Program (HDFP). The HDFP was a multi-center community-based trial, which followed 10,940 hypertensive participants for five years. One-year survival was required for inclusion in this investigation since the one-year annual visit was the first occasion where change in blood pressure could be measured on all participants. During the subsequent four years of follow-up on 10,052 participants, 568 deaths occurred. For levels of change in DBP and for categories of variables related to mortality, the crude mortality rate was calculated. Time-dependent life tables were also calculated so as to utilize available blood pressure data over time. In addition, the Cox life table regression model, extended to take into account both time-constant and time-dependent covariates, was used to examine the relationship change in blood pressure over time and mortality.^ The results of the time-dependent life table and time-dependent Cox life table regression analyses supported the existence of a quadratic function which modeled the relationship between DBP reduction and mortality, even after adjusting for other risk factors. The minimum mortality hazard ratio, based on a particular model, occurred at a DBP reduction of 22.6 mm Hg (standard error = 10.6) in the whole population and 8.5 mm Hg (standard error = 4.6) in the baseline DBP stratum 90-104. After this reduction, there was a small increase in the risk of death. There was not evidence of the quadratic function after fitting the same model using systolic blood pressure. Methodologic issues involved in studying a particular degree of blood pressure reduction were considered. The confidence interval around the change corresponding to the minimum hazard ratio was wide and the obtained blood pressure level should not be interpreted as a goal for treatment. Blood pressure reduction was attributed, not only to pharmacologic therapy, but also to regression to the mean, and to other unknown factors unrelated to treatment. Therefore, the surprising results of this study do not provide direct implications for treatment, but strongly suggest replication in other populations. ^

MARITAL STATUS AND CARDIOVASCULAR RISK (SERUM, CHOLESTEROL, CIGARETTE, SMOKING, BLOOD, PRESSURE, SYSTOLIC)

There were three purposes of this study. The first was to describe the association between stable marital status and serum cholesterol, systolic blood pressure and cigarette smoking. The second purpose was to determine whether individuals who were married at one point and became widowed or divorced/separated had higher serum cholesterol, higher systolic blood pressure or were more likely to smoke prior to the change in marital status compared with individuals who did not change marital status. The third purpose was to determine whether the changes in marital status described above were related to increases in serum cholesterol or in cigarette smoking behavior. The rationale for the study was to determine whether previously reported associations between marital status categories and cardiovascular mortality may be mediated through higher values of risk correlates for cardiovascular disease among unmarried individuals.^ The study group selected for this dissertation was a sample from the Hypertension Detection and Follow-up Program (HDFP) population. The HDFP population was aged 30-69 years at the initial visit and included blacks and whites, males and females. The population was followed five years after the initial visit and periodic measurements of serum cholesterol, blood pressure and cigarette smoking behavior were obtained.^ Serum cholesterol was not associated with stable marital status category or with marital status prior to change. Changes in serum cholesterol were associated with marital status categories after change but the serum cholesterol values deceased rather than increased. Married individuals were shown to have higher serum cholesterol values compared with unmarried. Selection of the HDFP population may have influenced an ability to detect a significant association between marital status and serum cholesterol but it is doubtful that use of a general population would alter the direction of the association.^ Systolic blood pressure was significantly higher at the initial visit among unmarried white males and females compared with their married counterparts. No association between systolic blood pressure was found among black males or females. Those individuals who were married at the initial visit who experienced a change in marital status were found to have higher systolic blood pressure prior to the change in marital status. . . . (Author's abstract exceeds stipulated maximum length. Discontinued here with permission of author.) UMI ^

REGRESSION ANALYSIS FOR STANDARDIZED MORTALITY RATIOS WITH APPLICATION TO OCCUPATIONAL FOLLOW-UP STUDIES

Traditional comparison of standardized mortality ratios (SMRs) can be misleading if the age-specific mortality ratios are not homogeneous. For this reason, a regression model has been developed which incorporates the mortality ratio as a function of age. This model is then applied to mortality data from an occupational cohort study. The nature of the occupational data necessitates the investigation of mortality ratios which increase with age. These occupational data are used primarily to illustrate and develop the statistical methodology.^ The age-specific mortality ratio (MR) for the covariates of interest can be written as MR(,ij...m) = ((mu)(,ij...m)/(theta)(,ij...m)) = r(.)exp (Z('')(,ij...m)(beta)) where (mu)(,ij...m) and (theta)(,ij...m) denote the force of mortality in the study and chosen standard populations in the ij...m('th) stratum, respectively, r is the intercept, Z(,ij...m) is the vector of covariables associated with the i('th) age interval, and (beta) is a vector of regression coefficients associated with these covariables. A Newton-Raphson iterative procedure has been used for determining the maximum likelihood estimates of the regression coefficients.^ This model provides a statistical method for a logical and easily interpretable explanation of an occupational cohort mortality experience. Since it gives a reasonable fit to the mortality data, it can also be concluded that the model is fairly realistic. The traditional statistical method for the analysis of occupational cohort mortality data is to present a summary index such as the SMR under the assumption of constant (homogeneous) age-specific mortality ratios. Since the mortality ratios for occupational groups usually increase with age, the homogeneity assumption of the age-specific mortality ratios is often untenable. The traditional method of comparing SMRs under the homogeneity assumption is a special case of this model, without age as a covariate.^ This model also provides a statistical technique to evaluate the relative risk between two SMRs or a dose-response relationship among several SMRs. The model presented has application in the medical, demographic and epidemiologic areas. The methods developed in this thesis are suitable for future analyses of mortality or morbidity data when the age-specific mortality/morbidity experience is a function of age or when there is an interaction effect between confounding variables needs to be evaluated. ^

RESPIRATORY COMPENSATION MECHANISMS IN THE UPPER AND LOWER RESPIRATORY TRACTS OF AN ANIMAL MODEL AFTER SUBCHRONIC INHALATION EXPOSURE TO FORMALDEHYDE: IMPLICATIONS FOR TOXICOLOGY RISK ASSESSMENT (DEPOSITION, DOSE RECEIVED, RESPONSE)

The potential for significant human populations to experience long-term inhalation of formaldehyde and reports of symptomatology due to this exposure has led to a considerable interest in the toxicologic assessment of risk from subchronic formaldehyde exposures using animal models. Since formaldehyde inhalation depresses certain respiratory parameters in addition to its other forms of toxicity, there is a potential for the alteration of the actual dose received by the exposed individual (and the resulting toxicity) due to this respiratory effect. The respiratory responses to formaldehyde inhalation and the subsequent pattern of deposition were therefore investigated in animals that had received subchronic exposure to the compound, and the potential for changes in the formaldehyde dose received due to long-term inhalation evaluated. Male Sprague-Dawley rats were exposed to either 0, 0.5, 3, or 15 ppm formaldehyde for 6 hours/day, 5 days/week for up to 6 months. The patterns of respiratory response, deposition and the compensation mechanisms involved were then determined in a series of formaldehyde test challenges to both the upper and to the lower respiratory tracts in separate groups of subchronically exposed animals and age-specific controls (four concentration groups, two time points). In both the control and pre-exposed animals, there was a characteristic recovery of respiratory parameters initially depressed by formaldehyde inhalation to at or approaching pre-exposure levels within 10 minutes of the initiation of exposure. Also, formaldehyde deposition was found to remain very high in the upper and lower tracts after long-term exposure. Therefore, there was probably little subsequent effect on the dose received by the exposed individual that was attributable to the repeated exposures. There was a diminished initial minute volume response in test challenges of both the upper and lower tracts of animals that had received at least 16 weeks of exposure to 15 ppm, with compensatory increases in tidal volume in the upper tract and respiratory rate in the lower tract. However, this dose-related effect was probably not relevant to human risk estimation because this formaldehyde dose is in excess of that experienced by human populations. ^

Anesthetic choices and breast cancer recurrence: A retrospective cohort study of risk factors

Background: The impact of anesthetic techniques for breast cancer surgery traditionally has been centered on the incidence of acute pain syndromes and complications immediately after surgery. Evaluating anesthesia management beyond short-term effects is an emerging science. Several animal studies have concluded that regional anesthesia independently reduces cancer recurrence and metastasis. A small number of retrospective clinical studies indicate that reductions in cancer recurrence are attributable to anesthesia technique; however, individual risk factors need to be taken into consideration. ^ Purpose: The aims were to: 1) investigate differences in patient, disease and treatment factors between women who received surgical treatment for breast cancer with paravertebral regional and general anesthesia compared to women who received general anesthesia alone; 2) explore patient, disease and treatment factors associated with recurrence of breast cancer; and 3) test the association between type of anesthesia and breast cancer recurrence and survival over 22–46 months following surgery. ^ Methods: This retrospective cohort study included 358 patients with stage 0-III disease who received a partial or total mastectomy without axillary node dissection between October 2006 and October 2008 at a large academic cancer center. Follow-up ended in August 2010 with a median follow-up time of 28.8 months. ^ Results: The patient demographics were equally represented across anesthesia groups. Mean BMI (kg/m2) was greater for the patients who received general anesthesia (GA) alone (29±6.8) compared to those that received paravertebral regional block (PVB) with GA (28±5.1), p=0.001. The PVB with GA group had more advanced stages of disease (p=0.01) and longer surgeries (p=0.01) than the GA only group. Breast cancer recurrence was detected in only 1.7% of the study population. The mean age was 51±18 in those who had a recurrence compared to 58±11 in the non-recurrent group (p=0.06). Overall, no association between anesthesia type and recurrence was found (p=0.53), with an unadjusted estimated hazard ratio of 1.84 (95% CI 0.34–10.08). ^ Conclusions: In contrast to previous retrospective studies in cancer patients receiving surgical and anesthesia treatment, this study was unable to detect a difference in relating type of anesthesia with decreased breast cancer recurrence. Nonetheless, a significant association between BMI and type of anesthesia was observed and should be taken into account in future studies. Because the overall rate of recurrence was very small in this population, a larger study would be needed to detect any differences in rates of recurrence attributable to type of anesthesia. ^

Long Term Follow-up of Morbidity and Quality of Life Associated with Isolated Gastroschisis

Gastroschisis is a birth defect in which an opening in the abdominal wall allows herniation of the viscera. Prenatal counseling regarding gastroschisis typically discusses that, although these infants often endure a difficult neonatal course, they experience few long-term complications. However, information regarding long-term outcomes is based on limited studies that lack specificity. Therefore, we aimed to study the long-term morbidity and quality of life in children born with gastroschisis in a large and diverse population drawn from the Texas Birth Defects Registry (TBDR). Study packets with informed consent, a questionnaire, and the Pediatric Quality of Life Inventory Generic Core Scale 4.0 (PedsQL 4.0) in English and Spanish were mailed to 1,112 parents of children born with isolated gastroschisis in Texas between 1999 and 2008 via the TBDR. Information was abstracted from the TBDR for 58 mothers of children with gastroschisis who returned study materials. Three hundred fifty five packets were returned to sender, giving a response rate of 7.7%. Children born with gastroschisis had quality of life scores that were not significantly different than expected (p = 0.981). However, factors such as having a learning disability (p = 0.001) and missing school due to gastrointestinal issues (p = 0.020) were found to significantly decrease quality of life. Overall, children with gastroschisis had a significantly increased risk for learning disabilities regardless of whether they were preterm (p = 0.021) or full term (p = 0.021). Additionally, there appeared to be an increased risk for auditory impairment in Caucasian children (p < 0.0005). Therefore, while overall long-term quality of life is not significantly altered for children born with gastroschisis, the previously unreported increased risk for learning disabilities and possible association with hearing impairment are important findings that should be conveyed to prospective parents.