The effect of dentin pre-treatment and heat-augmented cure on marginal gap formation of a dentin bonding agent

This study evaluated the effect of enhancing the cure of a DBA and the effect of dentin surface pre-treatment on marginal gap formation. Dentin cavities were prepared on extracted teeth and were pre-treated either with EDTA or phosphoric acid. Marginal leakage was expressed as percent length of margins with gaps. The mean percent length of margins with gaps for the chemically cured groups ranged from a maximum of 97% to a minimum of 85%. For the chemical/thermal-cured group, the mean percent length of margins with gaps was 95%, 95%, 73%, 35%, and 65%, corresponding to the following: pretreatment, no pre-treatment, EDTA, and phosphoric acid for 60, 15, or five s, respectively. SEM micrographs showed partial removal of one smear layer with EDTA and total removal of the smear layers with phosphoric acid. It is concluded that dentin pre-treatment methods have an effect on the percent length of margins with gaps when the DBA used had its cure supplemented with heat.

Renal preservation after warm ischemia using oxygen free radical scavengers to prevent reperfusion injury

Oxygen free radicals damage kidneys and accumulate during the period of preservation prior to transplantation. We hypothesized that a perfusate containing either an oxygen free radical scavenger such as ceruloplasmin, or an iron-chelating agent such as deferoxamine, would improve kidney preservation. Thirty-eight mongrel dogs underwent autotransplantation of the left kidney after 30 min of warm ischemia and 48 hr of machine perfusion (MOX-100, Water Instruments, Rochester, MN) at 5 degrees C and pH of 7.4. The right kidney was removed at the time of autotransplantation. Four blind code-labeled preservation solutions were tested. SGF-I was used for the control group (Group 1, n = 13), and the remaining animals were transplanted with kidneys preserved with one of three solutions modified from the basic SGF-I solution: Group 2, SGF-I plus deferoxamine (656 mg/liter), n = 8; Group 3, SGF-I ceruloplasmin enriched (72 mg/dl), n = 8; and Group 4, SGF-I ceruloplasmin reduced (3.4 mg/dl), n = 9. Serum creatinine levels were measured daily for 2 weeks and survival curves for each of the four groups were estimated by the Kaplan-Meier method. Peak mean serum creatinine levels +/- standard errors in Groups 1 through 4 were 12.6 +/- 1.97, 7.8 +/- 0.90, 7.1 +/- 1.26, and 8.2 +/- 1.09, respectively. Repeated measures analysis of variance showed statistically significant differences between the groups with respect to their serum creatinine profiles (Wald's test x2 with 3 df = 22.39, P value less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Elevated blood pressure among Southeast Asian refugee children in Minnesota

The blood pressures and body sizes of children aged 10-15 years in the Minneapolis and St. Paul, Minnesota, public schools were measured during 1986 and 1987. The sample consisted of 1,680 Southeast Asian refugees--including 219 Cambodians, 1,086 Hmong, 149 Lao, and 226 Vietnamese--and 3,424 blacks and 11,336 whites. Mean systolic blood pressure in Hmong boys was higher than that in black boys and white boys. Mean systolic blood pressures of Hmong, Lao, and Vietnamese girls were lower than those of black girls and white girls. The mean diastolic blood pressures of Hmong boys and of Cambodian and Hmong girls were greater than those of blacks and whites of the same sexes. Southeast Asian children were shorter and weighed less than black children and white children. Body size may confound associations between ethnic groups and blood pressures and may obscure the problem of hypertension among the smaller Southeast Asian children. Southeast Asian boys had greater mean systolic blood pressures than did black and white boys across all weight strata; a similar contrast among girls did not reveal this difference. The risk of hypertension, defined by US National Heart, Lung, and Blood Institute guidelines, was assessed in multiple logistic regression analyses that controlled for differences in weight, height, age, and pulse rate. The odds ratios for hypertension, relative to blacks and whites of the same sexes, were 2.69 (95% confidence interval (CI) 1.85-3.65) in Hmong boys, 2.89 (95% CI 1.35-6.21) in Lao boys, 2.10 (95% CI 1.03-4.28) in Cambodian girls, and 1.49 (95% CI 1.00-2.20) in Hmong girls. Hypertension and subsequent cardiovascular disease may emerge as a significant problem among Southeast Asian refugees in the United States.

Resin-bonded fixed partial dentures: a recall study

A clinical recall program was initiated at the University of Minnesota to evaluate the longevity and factors affecting longevity of resin-bonded fixed partial dentures (FPDs). Of the 49 resin-bonded FPDs evaluated in the clinic, 43 were acid-etched metal, resin-bonded FPDs, four were combinations of resin-bonded and conventional FPDs, and two were composite resin pontics. None of the combination FPDs and one of the two composite resin pontics were judged as failed at the examination. Of the 43 acid-etched metal resin-bonded FPDs, 15 were found to be debonded (failure rate = 34.9%). The average length of service for the 43 FPDs was 47.3 months. The average time of placement to debondment was 33 months for the 15 debonded FPDs. The failure rate for maxillary FPDs and FPDs with two retainers were significantly lower than the failure rate for mandibular FPDs and FPDs with more than two retainers (p greater than 0.05). The clinical significance of the present study was discussed.

Diastolic fourth and fifth phase blood pressure in 10-15-year-old children. The Children and Adolescent Blood Pressure Program

Measurement of diastolic blood pressure is complicated by the presence of two diastolic Korotkoff phases (fourth phase and fifth phase) in many children and adults. In the present study, diastolic fourth phase and diastolic fifth phase were evaluated in 1986-1987 in 19,274 Minneapolis-St. Paul school children aged 10-15 years. Approximately 50 percent of the children had no difference between fourth phase and fifth phase (i.e., fourth phase - fifth phase = 0) and 15 percent had a difference of only 1-4 mmHg. However, the fourth phase - fifth phase difference was 5-10 mmHg in 20 percent, 11-20 mmHg in 11 percent and greater than 21 mmHg in 3 percent of the children. Statistical analyses showed that the fourth phase - fifth phase difference tended to be greater in boys than girls and in older than younger children, was positively related to height, systolic blood pressure and fourth phase blood pressure, and negatively related to body mass index and fifth phase blood pressure. Using fifth phase instead of fourth phase in 10-12-year-old children and fourth phase instead of fifth phase in 13-15-year-old children to define diastolic blood pressures significantly changed the prevalence for significant diastolic hypertension by 2-3 percent.

Ratio of cuff width/arm circumference as a determinant of arterial blood pressure measurements in adults

Recommendations state that the optimum ratio of blood pressure cuff width/arm circumference (CW/AC) is about 0.4. In this study of middle-aged men (n = 940) and women (n = 1484), we analysed the effect of CW/AC on blood pressure measurement variability and its interaction with age, body mass index (BMI), pulse rate and room temperature. In univariate polynomial regression, the variability (R2) in blood pressure that was explained by CW/AC was greater for women (systolic 6.3% and diastolic 5.7%) than for men (2.0% and 0.5%). In multivariate analysis the maximum variability explained independently by CW/AC was 2.7% for male and 6.7% for female systolic blood pressure, and 1.1% and 6.0% for male and female diastolic blood pressure, respectively. For systolic blood pressure this represented 10.4% of the explained variability in men and 9.3% of that in women. CW/AC is an important independent contributor to inter-individual variation in blood pressure measurement. It should therefore be taken into consideration in epidemiological studies and when medical care is being planned.

Prevalence of "significant" hypertension in junior high school-aged children: the Children and Adolescent Blood Pressure Program

Blood pressure (BP) data obtained during a BP screening program were analyzed to determine the prevalence of "significant" hypertension, defined by the Second National Heart, Lung, and Blood Institute Task Force on Blood Pressure Control in Children-1987 as the level of BP above which medical evaluation and intervention are recommended. In 14,686 black and white St. Paul and Minneapolis schoolchildren aged 10 to 15 years, BP was measured twice during an initial screening examination. Children with systolic BP in the upper 30 percentiles of distribution after the initial screening had their BP remeasured two additional times at a rescreening examination. The prevalence of significant hypertension was determined according to BP criteria established by the Task Force report. After the two screening BP measurements were averaged, significant systolic hypertension was found in 1.0%, significant diastolic hypertension in 3.5%, and significant systolic or diastolic hypertension, or both, in 4.2% of the students. After the rescreening examination, the percentage of students remaining with significant hypertension was reduced to 0.3% for systolic, 0.8% for diastolic, and 1.1% for systolic or diastolic hypertension, or both. These results show that significant hypertension is uncommon in pre-high-school students and confirm the need for repeated BP measurements to make an accurate diagnosis of hypertension. However, the results should not detract from current recommendations to monitor BP in children on a yearly basis to detect longitudinal BP tracking patterns that may be consistent with early essential hypertension.

Canines erupted through grafted alveolar cleft defects in patients with alveolar clefts: a pulp testing evaluation study

An electric pulp tester (EPT) was used to evaluate the pulpal response of erupted canines in 75 patients: 16 patients with unilateral cleft palate who received autogenous bone grafts to correct their alveolar cleft defects before canine eruption; 35 patients without cleft palate whose canines erupted spontaneously, but who required orthodontic treatment for alignment; and 24 patients without clefts whose canines required surgical uncovering and orthodontic assistance for eruption. Thirty-one percent of the erupted canines in the patients with grafted unilateral clefts did not respond to EPT, whereas all canines in the contralateral noncleft side responded to EPT. There was no clinical or radiographic evidence of pulpal pathosis of the canines that had erupted through the grafted alveolar clefts. However, these teeth had a high incidence of nonresponsiveness to pulp stimulation, therefore necessitating close follow-up in case they show eventual signs of pulpal degeneration that may require endodontic intervention.

Postural changes in blood pressure and pulse rate among black adolescents and white adolescents: the Minneapolis Children's Blood Pressure Study

Because studies have suggested a possible relation between vascular responsiveness to postural changes and risk of subsequent myocardial infarction, the reactivity of blood pressure and pulse rate to change from supine to standing positions was examined in 158 black males, 144 black females, 342 white males, and 272 white females aged 14-16 years. The study was part of the Minneapolis Children's Blood Pressure Study and was conducted during October to December 1985. Two blood pressure readings and one pulse reading were taken after five minutes of supine rest, immediately upon standing, and five minutes after standing. After adjustment for body mass index, mean systolic blood pressure decreased, and fourth- and fifth-phase diastolic blood pressures and pulse rate increased from supine to standing positions in all race and sex groups. Black males had significantly larger changes in systolic pressure than did white males (-5.9 vs. -4.1 mmHg), and males had significantly larger changes in fourth- and fifth-phase diastolic pressures compared with females of the same race (fourth-phase diastolic pressure, 8.0 vs. 4.1 mmHg for blacks and 10.0 vs. 4.8 mmHg for whites). Fifth-phase diastolic pressure increased more than did fourth-phase diastolic pressure in all groups. No race or sex differences were seen for pulse changes. For all race-sex groups, decreases in systolic pressure were positively correlated with initial levels of supine systolic pressure, whereas increases in fourth- and fifth-phase diastolic pressures were negatively correlated with corresponding initial levels. Measurement of postural changes may provide a clinically simple and reproducible way of testing for abnormalities in blood pressure and may better discriminate those at high risk of hypertension and its cardiovascular complications than would the commonly used single-seated blood pressure measurement.

Persistent elevation of blood pressure among children with a family history of hypertension: the Minneapolis Children's Blood Pressure Study

We examined the blood pressure of children with and without a family history of hypertension in a longitudinal study. Supine blood pressures were first measured in schoolchildren (mean age 8 years) in 1978 and then on nine more occasions until 1986. Blood pressures of parents were measured in the seated position and their medical histories were obtained in home interviews carried out between 1978 and 1979. Children with a family history of hypertension had a higher mean systolic blood pressure (SBP) at the first screening compared to children without such a family history. This difference persisted at each of the succeeding nine school visits. The parents in hypertensive families had a lower income, greater body weight, were less well-educated and were more likely to be black than parents in families without a history of hypertension. Mothers in hypertensive families were more likely to have a history of heart disease and elevated blood pressure during pregnancy than mothers in normotensive families. The correlations between blood pressure of mothers and their children tended to be higher than those between fathers and their children. Elevated blood pressure emerges well before adolescence among children with a family history of hypertension and the family environment appears to play an important role in its development.

"Significant" diastolic hypertension in pre-high school black and white children. The children and adolescent blood pressure program

The Second Task Force on Blood Pressure Control in Children defines "significant" hypertension as blood pressure persistently above the 95th percentile for age-sex specific distribution. In this report we present preliminary data on the prevalence of significant diastolic hypertension in pre-high school black and white children after repeated blood pressure measurements. Blood pressure was measured in 10,446 children two times at an initial screening in school and remeasured two times at a rescreening in 2,808 children from the upper 30 percentiles of the initial screening distribution. Significant hypertension was found in 653 children (6.3%) after the first screening measurement and in 475 children (4.5%) after averaging the first two screening measurements. At the rescreening, the prevalence of significant hypertension was further reduced in this cohort to 1% after one measurement and to 0.8% after averaging the two measurements. The prevalence of significant systolic hypertension had fallen to 0.47% after averaging the two rescreening measurements. These data suggest that the prevalence of significant hypertension is very low in pre-high school children.

Discrepancies in racial designations of school children in Minneapolis

To determine the frequency of inaccuracies in racial designations of school children in a health survey, racial designations were examined for a sample of 1,509 children in Minneapolis public schools who participated in the first home interview of the Minneapolis Children's Blood Pressure Study. The data were obtained from three sources: the school enrollment data based on parentally supplied information and teachers' visual judgments, school survey interviewers participating in a research project, and the parents themselves, at home interviews. Assuming the correctness of the information obtained from the parent in the home interview, cross tabulation comparisons were made of the accuracy of the information obtained from the other sources, and within sources. Results show a high degree of agreement between the parents' or teachers' designations at enrollment, and survey interviewers' sight judgments. Furthermore, sight judgments of interviewers show high repeatability. There was a significant degree of disagreement between the designations by teachers' and screeners' visual judgments, obtained in school, and the interviews with the parents. Misidentification occurred for up to 20 percent of Native American children, a rate which, if prevalent, may significantly affect public health studies which are based on racial identifications of school children. When possible, researchers studying Native American or mixed race populations should verify racial designations from school documents or sight judgments. Questionnaires to be answered by parents need to have sufficiently detailed categories to enable parents of different racial groups to identify different racial groups accurately.

Trends in cardiovascular risk factors in an urban black population, 1973-74 to 1985: the Minnesota Heart Survey

Cardiovascular disease mortality rates have fallen dramatically in blacks in the United States. To determine whether this may be due to a decline in cardiovascular risk factors, we compared risk factors in a 1985 urban black population, ages 35 to 69, with those obtained in blacks of the same area in 1973-74. Age-adjusted mean body mass and the prevalence of overweight increased significantly over the 12-year period in both men and women. Mean systolic blood pressures declined significantly in both sexes, diastolic blood pressure declined significantly in men, and the proportion of men and women hypertensives on medication and under control increased. The overall prevalence of cigarette smoking changed very little, but the proportion of heavy smokers decreased significantly in men. No significant changes occurred in resting heart rate. Concurrently with these risk factor trends, age-adjusted heart disease mortality rates in area blacks fell 27% between 1968-73 and 1979-84, and stroke mortality fell 58%. Changing risk factors may be contributing to declining cardiovascular mortality rates in blacks. However, overweight seems to be a worsening problem.

Out-of-hospital coronary death in an urban population--validation of death certificate diagnosis. The Minnesota Heart Survey

To assess the validity of death certificate diagnoses of out-of-hospital coronary heart disease deaths, the authors studied a one-third random sample of out-of-hospital deaths occurring in 1979 in Minneapolis-St. Paul, Minnesota, residents. Death certificates with diagnoses possibly containing coronary heart disease deaths were enumerated, and cause of death was recorded from the certificate in two ways: as the first listed ("immediate") cause and as the "underlying cause" assigned by a trained nosologist. Validation was performed by standardized physician review of information obtained about the death, which included one or more of the following: an interview with a relative or friend, physician report, autopsy report, medical record, and/or nursing home record. Missing information was frequent, but cases with at least an informant interview and/or autopsy report (82%) were representative and could be used for validation. The sensitivity and specificity of the underlying cause of coronary heart disease (International Classification of Diseases, Ninth Revision, codes 410-414, 427) on the death certificate were 90.3% and 82.7%, respectively, compared with the physician-assigned diagnosis. For the immediate cause, sensitivity and specificity were 90.3% and 67.9%, respectively. These findings suggest that the validity of death certificates for out-of-hospital coronary heart disease death is high, as assessed by this method of retrospective physician review.

Improvement in long-term survival among patients hospitalized with acute myocardial infarction, 1970 to 1980. The Minnesota Heart Survey

The mortality rate associated with coronary heart disease in the United States has declined steadily since 1968, but the reasons for this favorable trend have not been completely elucidated. In particular, it is not clear to what extent the decline reflects decreasing incidence as opposed to improved survival. To assess whether improved survival after myocardial infarction has contributed to the decline, the Minnesota Heart Survey compared the four-year survival rate in patients discharged with a diagnosis of acute myocardial infarction from hospitals in the Twin Cities area in 1970 and 1980. After adjustment for clinical characteristics related to outcome, the survival rate among patients with a definite myocardial infarction was significantly higher in the 1980 than in the 1970 group. The four-year survival for men was 35 percent better in the 1980 than in the 1970 group (95 percent confidence interval, 21 to 50 percent), and for women it was 27 percent better (95 percent confidence interval, 1 to 46 percent). Improvement in survival during the period of hospitalization accounted for 70 percent of the overall gain in survival between 1970 and 1980 in men and for virtually all of the gain in women. We conclude that improved long-term survival among patients with acute myocardial infarction has made an important contribution to the decline in mortality from coronary disease.

A comparative study of the effects of dentinal bonding agents and application techniques on marginal gaps in Class V cavities

The effectiveness of eight dentinal bonding agents (DBA's) and four of their combinations in eliminating marginal gaps in class V cavities was evaluated by the bulk method of composite application and two different incrementation techniques. The cavities were prepared one-half in enamel and one-half in dentin. Basic fuchsin 0.5% in propylene glycol was used for detection of the presence of gaps. For each cavity, the presence of gaps was scored as 0 or 1, at five enamel and five dentin locations. Marginal gaps were present in 6% of all enamel locations and in 75% of all dentin locations investigated. The gap frequency was lowest at the enamel occlusal locations, it increased gradually toward the dentin, and attained the highest value at the gingival locations. In enamel, the occurrence of gaps was dependent on the DBA's but independent of the particular technique used. In dentin, there was significant difference in gap occurrence between DBA's with any of the incrementation techniques. The frequency of gap occurrence was not significantly changed by the incrementation techniques. The most effective single agent in producing gap-free restorations was the Gluma, and the most effective combination was the Gluma/Clearfil.

Cardiac status of adolescents tracking with high and low blood pressure since early childhood

The risk of cardiovascular disease for children in the upper percentiles of the blood pressure distribution for age has not been determined. In this study echocardiographic evaluation was conducted at age 15 years in eight children tracking in the 89 +/- percentile for systolic blood pressure since age 8 years, and compared with nine children tracking in the 28 +/- 3 percentile over the same period. No significant differences were observed for left ventricular size, septal or posterior wall thickness or relative wall thickness using raw data, after adjustment for body mass index or after regression analysis using systolic blood pressure as the dependent variable. In contrast, stroke volume, cardiac output and left ventricular fractional shortening were greater in the high blood pressure group after adjustment for body mass index (P = 0.006, 0.075 and 0.08, respectively). These results suggest that changes consistent with previously reported findings in adults with essential hypertension (i.e. and increase in cardiac performance with normal peripheral resistance) are also early findings in adolescents tracking with high blood pressure.

Electrolytes and blood pressure levels in childhood hypertension: measurement and change

Research into the relationship between dietary electrolytes and the primary cause and treatment of hypertension has now reached the stage where long-term, detailed, controlled, randomized, clinical trials of intervention need to be carried out among those at high risk, including children. Such trials must incorporate methods for estimating "sensitive" responders. The designs should also include precise measures of change in dietary electrolyte intake and allow for analysis of interaction of the effects of individual electrolytes. We have sketched the unforeseen errors, that now must be avoided, from earlier studies and given an outline of a current study that sets out to meet optimum requirements. It is to be hoped that many similar studies will soon be initiated in multiple population groups.

Test-retest reliability of the Minnesota Leisure Time Physical Activity Questionnaire

The test-retest reliability of the Minnesota Leisure Time Physical Activity Questionnaire was assessed by two administrations of the questionnaire at a five-week interval in 140 adults from a general population sample and at a two-week interval in 150 male participants in the Multiple Risk Factor Intervention Trial (MRFIT). In both study populations, there was a slight, nonsignificant drop in reported leisure time energy expenditure between the test and the retest. The largest test-retest differences in estimated energy expenditure were found among those reporting greater levels of energy expenditure. Nevertheless, in both study populations Spearman rank correlation coefficients between the test and retest were high--0.79 to 0.88 for total activity and ranging 0.69-0.86 among the light, moderate, and heavy intensity subcategories. The high reliability of the Minnesota Leisure Time Physical Activity Questionnaire corroborates its utility in epidemiologic research.

Leisure time physical activity and its relationship to coronary risk factors in a population-based sample. The Minnesota Heart Survey

Energy expenditure in leisure time physical activity was measured using the Minnesota Leisure Time Physical Activity Questionnaire in a probability sample of 25- to 74-year-old residents of the seven-county metropolitan area of Minneapolis-St. Paul, Minnesota. Geometric mean estimates of leisure time physical energy expenditure were 193 kcal per day for men and 111 kcal per day for women. Only 34% of men and 17% of women expended 2,000 kcal or more per week in leisure time physical activity. Energy expenditure, especially in heavy intensity activities, declined with age, more so for women than men. Significant associations were observed between leisure time physical activity, particularly heavy intensity activity, and other coronary heart disease risk factors. Greater heavy intensity activity was associated with higher education (r = 0.14 to 0.26), greater Type A behavior (r = 0.14 to 0.15), higher serum high density lipoprotein (HDL) cholesterol levels (r = 0.09 to 0.10), lower serum thiocyanate (r = 0.10 to -0.14), lower body mass index (r = -0.10 to -0.11), lower heart rate (r = -0.07 to -0.10), and lower systolic blood pressure (r = -0.06 to -0.09). Thus, although energy expenditure was generally low in this population, greater leisure time physical activity for the most part was associated with lower coronary risk factors.

Acute stroke in a metropolitan area, 1970 and 1980. The Minnesota Heart Survey

Mortality rates for stroke, and hospitalization and case fatality rates for acute stroke in 1970 and 1980 were obtained for residents aged 30-74 of the Twin Cities (Minneapolis--St Paul) metropolitan area to determine whether improved hospital care contributed to the decline in stroke mortality. Age-adjusted mortality rates per 100,000 declined significantly in that decade for men (1970, 89.4; 1980, 47.5; p less than 0.01) and women (1970, 72.6; 1980, 40.9; p less than 0.01). Age-adjusted hospitalization rates per 100,000 population also declined significantly for men (1970, 438; 1980, 323; p less than 0.01) and women (1970, 331; 1980, 203; p less than 0.01). Age-adjusted mean length of hospital stay did not change significantly. Hospital case fatality declined for men aged 30-64 years (1970, 22.5%; 1980, 15.1%; p less than 0.01) but did not change significantly for 65 to 74 year-old men (1970, 16.5%; 1980, 20.0%; p = 0.09) or for all women (age-adjusted rates: 1970, 13.6%; 1980, 16.0%; p = 0.17). There was no change in the distribution of severity of hospitalized cases between years. Therefore, the decline in stroke mortality is consistent with a decreased incidence of stroke resulting from improved hypertension control. Improvements in hospital medical care appear not to have contributed substantially to the decline in stroke mortality.

Personality, behavior, family environment, family social status and hypertension risk factors in children. The Minneapolis Children's Blood Pressure Study

To assess the relationship of psychosocial variables to risk factors for hypertension in children, we administered instruments designed to measure aspects of children's personality, behavior, family environment and family social status to 1505 school children aged 7-10 years. Children's blood pressure was significantly related only to mother's occupation, the children of unskilled employees having higher blood pressure than children of higher status workers. Children's body mass index was directly related to scores on the conformity scale of the personality inventory and inversely related to scores on the intellectual-cultural orientation scale of the family environment instrument and to social class. Social status but not measured dimensions of children's personality, behavior and family environment may influence the risk of hypertension in children.

Racial differences in personality, behavior, and family environment in Minneapolis school children

Racial differences in personality, behavior, and family environment of lower elementary school children were examined in a sample of 433 black and 897 white children. Numerous significant differences in scores on scales of the Missouri Children's Picture Series, the Missouri Children's Behavior Checklist, and the Family Environment Scale persisted after adjustment for socioeconomic status.