Biomedical subjects

Nicholas J Horton

Publications and source records attributed to Nicholas J Horton.

51 records · Page 3Linked to original sources

PubMed2003

Multiple informants: a new method to assess breast cancer patients' comorbidity.

Past assessments of comorbidity indices have sought to recommend a single index that performs better than others. The authors used a multiple informants approach as an alternative method to simultaneously assess five indices of comorbidity. This approach provides a single estimate of the overall effect of comorbidity and evaluates the relation any individual index has to the outcomes of interest. Association of comorbidity with definitive primary therapy, discussion of tamoxifen, and receipt of tamoxifen was evaluated in a cohort of 830 older breast cancer patients enrolled at four geographically distinct centers in the United States from 1996 to 1999. The estimated adjusted effect of a unit increase in comorbidity on the odds of discussing tamoxifen therapy was 0.70 (95% confidence interval: 0.56, 0.88). An increase in comorbidity was not associated with receipt of definitive primary therapy (odds ratio = 0.94, 95% confidence interval: 0.79, 1.13) or receipt of tamoxifen (odds ratio = 0.96, 95% confidence interval: 0.72, 1.27). The multiple informants regression proved superior to separate regression models that included only one index. In analyses that require comorbidity adjustment and for which no single index is expected to be ideal, the multiple informants approach is an attractive alternative to selecting a single index and to other methods of using multiple indices.

Aged↗

PubMed2003

Slowing the revolving door: stabilization programs reduce homeless persons' substance use after detoxification.

This study examined whether homelessness predicted earlier resumption of substance use after detoxification, and sought evidence concerning the impact of post-detoxification stabilization programs among homeless and nonhomeless individuals. Kaplan-Meier plots and proportional hazards models were used to determine the association between homelessness, stabilization program use, and recurrent substance use in a prospective cohort of persons entering inpatient detoxification (n=470). Among 254 persons available at 6 months, 76% reported recurrent substance use. Homeless persons not using stabilization programs experienced the highest hazard of return to substance use after detoxification, Hazard Ratio (HR) 1.26, 95% CI (0.88, 1.80). Homeless persons using these programs had the lowest rate of return to substance use: HR 0.61, 95% CI (0.40, 0.94). A similar impact of stabilization programs was not seen among nonhomeless subjects. Post-detoxification stabilization programs were associated with improved outcomes for homeless addicted persons. This treatment modality may slow the "revolving door" phenomenon of relapse after detoxification among homeless persons.

Adult↗

PubMed2003

Substance abuse treatment and emergency department utilization among a cohort of HIV-infected persons with alcohol problems.

We examined the association between substance abuse treatment services and emergency department (ED) utilization among participants in the HIV-Alcohol Longitudinal Cohort study of HIV-infected persons with a history of alcohol problems. A standardized questionnaire was administered to 350 subjects inquiring about demographics, substance use, use of substance abuse treatment services, and ED attendance. We operationally defined substance abuse treatment services as: stable, unstable, or none. The outcome, ED attendance, defined as presenting to an ED without subsequent hospitalization, occurred in 101 (28.8%) subjects in the past 6 months. Stable substance abuse treatment was significantly associated with lower odds of ED attendance (adjusted odds ratio; 95% CI): (0.5; 0.3-0.9). The relationship between substance abuse treatment and HIV-infected individuals' use of health care services merits additional attention. Substance abuse treatment may present an opportunity to impact health care utilization patterns of HIV-infected persons with a history of alcohol problems.

Adult↗

PubMed2003

A prospective study of the effect of childbearing on weight gain in African-American women.

OBJECTIVE: To prospectively assess the influence of bearing a first, second, or later child on weight gain among African-American women in the context of other risk factors. RESEARCH METHODS AND PROCEDURES: Data were obtained in a prospective follow-up study of African-American women from across the U.S. who are participants in the Black Women's Health Study. Postal questionnaires were used to collect baseline data in 1995 and follow-up data in 1997 and 1999. Parous and nulliparous women (11,196) (21 to 39 years old at baseline), of whom 1230 had a singleton birth during follow-up, are the subjects of the present analyses. We assessed change in BMI (kilograms per meter squared) in relation to childbearing during 4 years of follow-up, with use of multivariable linear regression to control for important risk factors. RESULTS: During 4 years of follow-up, the BMI of participants increased by an average of 1.6 kg/m2, equivalent to a weight gain of approximately 4.4 kg. Women who had a child during follow-up gained more weight than women who remained nulliparous, and those who had a first child gained more than those who had a second or later child. The weight gain associated with childbearing increased with increasing baseline BMI and was appreciable among heavier women. For example, among women with a baseline index of 36, the increase in BMI for women who bore a first child was 1.1 kg/m2 more than that of nulliparous women, equivalent to a difference in weight gain of approximately 3.0 kg. DISCUSSION: Childbearing is an important contributor to weight gain among African-American women.

Adult↗

PubMed2003

Linking alcohol- and drug-dependent adults to primary medical care: a randomized controlled trial of a multi-disciplinary health intervention in a detoxification unit.

AIM: Pragmatic approaches to integration of medical care and substance abuse treatment are desired. We assessed the effectiveness of a novel multi-disciplinary clinic for linking patients in a residential detoxification program to primary medical care. PARTICIPANTS: We enrolled patients undergoing in-patient detoxification from alcohol, heroin or cocaine who had no primary care physician into a randomized controlled trial. The intervention consisted of a clinical evaluation at the detoxification unit in the health evaluation and linkage to primary care (HELP) clinic by a nurse, social worker and physician and facilitated referral to an off-site primary care clinic. The primary outcome of interest was attendance at a primary care appointment within 12 months. Secondary outcomes assessed over 24 months were addiction severity, health-related quality of life, utilization of medical and addiction services and HIV risk behaviors. FINDINGS: Of the 470 subjects enrolled, 235 were randomized to the HELP clinic intervention. Linkage to primary medical care occurred in 69% of the intervention group compared to 53% in the control group (P = 0.0003). The clinic was similarly effective for subjects with alcohol and illicit drug problems. Randomization to the HELP clinic resulted in no significant differences in secondary outcomes. CONCLUSIONS: The HELP clinic, a multi-disciplinary clinic located in a detoxification unit, effectively linked alcohol- and drug-dependent individuals to primary medical care. This intervention utilized a 'reachable moment', the period of addiction care, as a window of opportunity for linking substance abusers to medical care.

Adolescent↗

PubMed2003

A review and new report of medial temporal lobe dysfunction as a vulnerability indicator for schizophrenia: a magnetic resonance imaging morphometric family study of the parahippocampal gyrus.

A central question in schizophrenia research is which brain abnormalities are independent of psychosis and which evolve before and after psychosis begins. This question can be addressed by longitudinal neuroimaging studies beginning in the prodrome, but at present there is only one published study. We reviewed the literature on structural brain imaging in persons with chronic and first episode schizophrenia, nonpsychotic persons at genetic high risk, and persons thought to be at risk for imminent psychosis ("prodromal" persons). Medial temporal lobe (MTL), especially hippocampal, volume alterations are among the most robust brain vulnerabilities for schizophrenia. Because verbal declarative memory (VDM) deficits are prominent and the parahippocampal gyrus (PHG) is considered to be centrally involved with the hippocampus in VDM processing, we analyzed PHG data from a family study of schizophrenia. Patients with schizophrenia and nonpsychotic relatives from "multiplex" families (families with multiple persons with schizophrenia) had significantly smaller right parahippocampal anterior (PHa) volumes than controls. Marginally significant findings were observed for the left PHa. Unexpectedly, relatives from "simplex" families (families with only one person with schizophrenia) had significantly larger PH posterior volumes than controls and did not differ from controls on PHa. Results provide some support for the hypothesis that the vulnerability to schizophrenia includes abnormal volumes of the PHG. These data provide additional support for the hypothesis that some MTL abnormalities in schizophrenia are independent of psychosis, at least in families with presumably high genetic loading. Implications of genetic risk studies for prodromal research are discussed.

Adult↗

PubMed2003

Alcohol consumption and HIV disease progression: are they related?

BACKGROUND: The relationship between alcohol consumption and HIV disease progression has received limited attention in the era of highly active antiretroviral therapy (HAART). METHODS: We assessed CD4 cell count, HIV RNA levels, and alcohol consumption in the past month, defined as none, moderate, and at risk, in 349 HIV-infected people with a history of alcohol problems. We investigated the relationship between alcohol consumption and HIV disease markers CD4 cell count and HIV RNA level, stratified by HAART use, using multivariable regression. RESULTS: No significant differences in CD4 cell count or HIV RNA level were found across the categories of alcohol consumption for patients who were not receiving HAART. However, among patients who were receiving HAART, log HIV RNA levels were significantly higher in those with moderate (2.17 copies/ml) and at-risk (2.73 copies/ml) alcohol use compared with none (1.73 copies/ml; p = 0.006). CD4 cell counts in those with moderate (368 cells/microl) and at-risk (360 cells/microl) alcohol use were lower than for subjects who reported none (426 cells/microl; p = 0.07). CONCLUSION: Among patients who have a history of alcohol problems and are receiving antiretroviral treatment, alcohol consumption was associated with higher HIV RNA levels and lower CD4 counts. No comparable association was found for similar patients who were not receiving HAART. Addressing alcohol use in HIV-infected patients, especially those who are receiving HAART, may have a substantial impact on HIV disease progression.

Alcohol Drinking↗

PubMed2003

Cigarette smoking in relation to depression: historical trends from the Stirling County Study.

OBJECTIVE: Building on findings about the prevalence and incidence of depression over a 40-year period, the authors provide data on trends in cigarette smoking and associations with depression. METHOD: Data come from interviews with adult population samples (1952, 1970, and 1992) and followed cohorts (1952-1970 and 1970-1992). Logistic regression models and survival regressions were used to analyze the data. RESULTS: The associations between smoking and depression were small and nonsignificant in 1952 and 1970. In 1992, however, the odds that a smoker would be depressed were three times the odds that a nonsmoker would be depressed. The interaction between smoking and study year was significant, indicating that the association was limited to the most recent sample. In the cohort analysis, smoking at baseline did not predict the onset of depression, but subjects who became depressed were more likely to start or continue smoking and less likely to quit than those who never had a depression. CONCLUSIONS: In terms of population trends, the association between depression and cigarette smoking became prominent as the use of tobacco declined because of awareness of the risks involved. The findings about individuals followed over time suggest that those who became depressed were more involved with nicotine than those who never had a depression. The authors discuss hypotheses involving "self-medication," risk-taking, and changes in the social climate but conclude that the relationships between smoking and depression are probably multiple and complex.

Adult↗

PubMed2003

Onset of natural menopause in African American women.

OBJECTIVES: This study assessed predictors of the onset of natural menopause in African American women. METHODS: We used mailed questionnaires to collect data at baseline in 1995 and during follow-up from Black Women's Health Study participants. Cox proportional hazards regression was used to assess potential predictors-including experiences of racism-of the onset of natural menopause among 17 070 women aged 35 to 55 years and premenopausal in 1995. RESULTS: The hazard ratio (HR) was 1.43 for current smokers (95% confidence interval [CI] = 1.24, 1.66) and 1.21 (95% CI = 1.06, 1.38) for ex-smokers and significantly less for obese women and oral contraceptive users. Hazard ratios for most questions about racism were elevated by 10% to 30% but were not statistically significant. CONCLUSIONS: Earlier onset of natural menopause among African American women is strongly associated with smoking and inversely associated with body mass index and oral contraceptive use.

Adult↗

PubMed2002

Sex differences in clinical response to olanzapine compared with haloperidol.

There is current disagreement over whether men and women respond differently to typical or atypical antipsychotic medications. This study reanalyzed a large international clinical trial of olanzapine (Olz) compared with haloperidol (Hal) to test for sex differences in treatment response, controlling for illness chronicity and menopausal status. We hypothesized that women would show a greater response to either medication than men, particularly among first admission, premenopausal women. DSM-III-R schizophrenia inpatients (700 women and 1295 men) were randomly assigned to a 6-week trial of Olz vs. Hal. Longitudinal random effect models were used to test for interactions of sex with medication, chronicity and menopausal status on treatment response. Findings showed that women on olanzapine had a greater drop in overall symptomatology by week 4 than any other group, and their level of symptomatology remained lower throughout the 6-week trial. The sex differences in treatment response in olanzapine compared with haloperidol were, in part, dependent on chronicity and, in women, menopausal status. That is, first episode women on haloperidol exhibited an increase in symptomatology over the 6-week trial compared to their male counterparts, while multiply hospitalized women had a better treatment response on haloperidol than their male counterparts. Women on olanzapine had a significantly better treatment response than men, regardless of chronicity. Finally, premenopausal women had a significantly better treatment response than postmenopausal women, regardless of treatment and chronicity.

Adult↗

PubMed2002

Impact of normal sexual dimorphisms on sex differences in structural brain abnormalities in schizophrenia assessed by magnetic resonance imaging.

BACKGROUND: Previous studies suggest that the impact of early insults predisposing to schizophrenia may have differential consequences by sex. We hypothesized that brain regions found to be structurally different in normal men and women (sexual dimorphisms) and abnormal in schizophrenia would show significant sex differences in brain abnormalities, particularly in the cortex, in schizophrenia. METHODS: Forty outpatients diagnosed as having schizophrenia by DSM-III-R were systematically sampled to be comparable within sex with 48 normal comparison subjects on the basis of age, ethnicity, parental socioeconomic status, and handedness. A comprehensive assessment of the entire brain was based on T1-weighted 3-dimensional images acquired from a 1.5-T magnet. Multivariate general linear models for correlated data were used to test for sex-specific effects regarding 22 hypothesized cortical, subcortical, and cerebrospinal fluid brain volumes, adjusted for age and total cerebrum size. Sex x group interactions were also tested on asymmetries of the planum temporale, Heschl's gyrus, and superior temporal gyrus, additionally controlled for handedness. RESULTS: Normal patterns of sexual dimorphisms were disrupted in schizophrenia. Sex-specific effects were primarily evident in the cortex, particularly in the frontomedial cortex, basal forebrain, cingulate and paracingulate gyri, posterior supramarginal gyrus, and planum temporale. Normal asymmetry of the planum was also disrupted differentially in men and women with schizophrenia. There were no significant differential sex effects in subcortical gray matter regions or cerebrospinal fluid. CONCLUSION: Factors that produce normal sexual dimorphisms may be associated with modulating insults producing schizophrenia, particularly in the cortex.

Adult↗

PubMed2002

Left hippocampal volume as a vulnerability indicator for schizophrenia: a magnetic resonance imaging morphometric study of nonpsychotic first-degree relatives.

BACKGROUND: Clues to the causes of schizophrenia can be derived from studying first-degree relatives because they are genetically related to an ill family member. Abnormalities observed in nonpsychotic relatives are indicators of possible genetic vulnerability to illness, independent of psychosis. We tested 4 hypotheses: (1) that hippocampal volume is smaller in nonpsychotic relatives than in controls, particularly in the left hemisphere; (2) that hippocampi will be smaller in multiplex relatives as compared with simplex relatives, and both will be smaller than in controls; (3) that hippocampal volumes and verbal declarative memory function will be positively correlated; and (4) that hippocampi will be smaller in patients with schizophrenia than in their nonpsychotic relatives or in controls. METHODS: Subjects were 45 nonpsychotic adult first-degree relatives from families with either 2 people ("multiplex," n = 17) or 1 person ("simplex," n = 28) diagnosed with schizophrenia, 18 schizophrenic relatives, and 48 normal controls. Sixty contiguous 3-mm coronal, T1-weighted 3-dimensional magnetic resonance images of the brain were acquired on a 1.5-T magnet. Volumes of the total cerebrum and the hippocampus were measured. RESULTS: Compared with controls, relatives, particularly from multiplex families, had significantly smaller left hippocampi. Verbal memory and left hippocampal volumes were significantly and positively correlated. Within families, hippocampal volumes did not differ between schizophrenic patients and their nonpsychotic relatives. CONCLUSIONS: Results support the hypothesis that the vulnerability to schizophrenia includes smaller left hippocampi and verbal memory deficits. Findings suggest that smaller left hippocampi and verbal memory deficits are an expression of early neurodevelopmental compromise, reflecting the degree of genetic liability to schizophrenia.

Adult↗

PubMed2002

The relationship between sexual and physical abuse and substance abuse consequences.

This study examines the relationship between a history of physical and sexual abuse (PhySexAbuse) and drug and alcohol related consequences. We performed a cross-sectional analysis of data from 359 male and 111 female subjects recruited from an inpatient detoxification unit. The Inventory of Drug Use Consequences (InDUC), measured negative life consequences of substance use. Eighty-one percent of women and 69% of men report past PhySexAbuse, starting at a median age of 13 and 11, respectively. In bivariate and multivariable analyses, PhySexAbuse was significantly associated with more substance abuse consequences (p < 0.001). For men, age < or =17 years at first PhySexAbuse was significantly associated with more substance abuse consequences than an older age at first abuse, or no abuse (p = 0.048). For women, the association of PhySexAbuse with substance use consequences was similar across all ages (p = 0.59). Future research should develop interventions to lessen the substance abuse consequences of physical and sexual abuse.

Adult↗

PubMed2002

Perceptions of racial discrimination and the risk of preterm birth.

BACKGROUND: Because racial discrimination might contribute to their excess of preterm births, we assessed experiences of racism in relation to preterm birth among African-American women. METHODS: We used data from the Black Women's Health Study, a follow-up study of African-American women begun in 1995. Data on subsequent singleton births were obtained using follow-up questionnaires in 1997 and 1999; nine questions about experiences of racism were asked in 1997. We compared mothers of 422 babies born 3 or more weeks early (because of premature labor for unknown reasons or rupture of membranes) with mothers of 4544 babies of longer gestation. We used generalized estimating equation models to estimate odds ratios (ORs) for preterm birth, controlling potential confounders. RESULTS: The adjusted ORs for preterm birth were 1.3 (95% confidence interval [CI] = 1.1-1.6) for women who reported unfair treatment on the job and 1.4 (1.0-1.9) for women who reported that people acted afraid of them at least once a week. Overall ORs for the seven other racism questions were close to 1.0. Among 491 women with </=12 years of education, ORs were 2.0 or greater for four racism variables. CONCLUSIONS: These data provide some evidence for an increase in preterm birth among women who report experiences of racism, particularly women with lower levels of education.

Black People↗

PubMed2002

Injury among detoxification patients: alcohol users' greater risk.

BACKGROUND: Little information exists about serious injury in alcohol or drug abusers who seek detoxification. This study examined injury prevalence, and the impact of alcohol use on injury, among alcohol- and drug-dependent persons. METHOD: We enrolled patients at a detoxification unit into a prospective cohort study and performed follow-up interviews to determine the prevalence of injury. Baseline and follow-up (6, 12, 18, and 24 month) data were examined separately by using multivariate logistic regression to determine factors associated with self-reported episodes of serious injury. The main independent variable was self-reported first and second substances of choice at admission: alcohol only, drug only, or both. RESULTS: Overall, 24% of the 470 subjects reported at least one instance of serious injury over the 6-month period before detoxification. Similarly, approximately 20% of subjects had serious injury during each 6-month follow-up period. Injury in the past 6 months was highest among the 63% of subjects who reported alcohol as a drug of choice (28-29% vs. 16% for drug only), even after we controlled for potential confounders. Analysis of 2-year follow-up data revealed a similar association, after we controlled for baseline injury and alcohol consumption. CONCLUSIONS: Injury is a serious problem for a substantial proportion of patients who undergo detoxification, particularly those with alcohol dependence. This marked risk for serious injury persisted for 24 months after detoxification. Patients at detoxification, particularly those with alcohol problems, represent a high-risk population for injury that may benefit from interventions to reduce these preventable complications.

Adult↗