Biomedical subjects

H C Kraemer

Publications and source records attributed to H C Kraemer.

At least 19 recordsLinked to original sources

PubMed2006

Spatial test for agricultural pesticide "blow-in" effect on prevalence of Parkinson's disease.

The current study used Department of Veteran's Affairs (VA) clinical records, State of California pesticide application records, spatial maps of distribution of Parkinson's disease patients, and pesticide applications to determine if there was evidence for "blow-in" of pesticides as a factor in explaining the prevalence of Central Valley Parkinson's disease. The results did not support the hypothesis of increasing prevalence of Parkinsonism attributable to wind drift.

Agriculture↗

PubMed2005

Nocturnal sleep apnea/hypopnea is associated with lower memory performance in APOE epsilon4 carriers.

The authors investigated the relationship between obstructive sleep apnea/hypopnea (OSAH) and cognition in 36 older adults, 18 APOE epsilon4 carriers, and 18 non-carriers. Greater numbers of respiratory events negatively impacted memory function in epsilon4 carriers only. This is the first study to provide preliminary evidence for a negative interaction of APOE epsilon4 and OSAH on memory in older adults, which may have important implications for treating cognitive decline and delaying dementia onset.

Aged↗

PubMed2004

Use of a VA pharmacy database to screen for areas at high risk for disease: Parkinson's disease and exposure to pesticides.

The purpose of this study was to assess whether pharmacy database information from US Department of Veterans Affairs (VA) medical centers could be used to screen for areas of higher Parkinson's disease prevalence in patients exposed to pesticides. The authors used pharmacy data sets and compared the use of antiparkinsonian medications at 2 VA medical centers in California: one in Palo Alto, near the ocean, and one in Fresno, downwind from extensively farmed parts of the Central Valley. They found that patients at Fresno had higher odds ratios (1.5-1.8) for the use of Parkinson's disease medications than patients at Palo Alto. These data are consistent with the observations of prior epidemiologic studies and suggest that VA pharmacy databases can prioritize locations for further epidemiologic research. However, a thorough exploration of alternative explanations is needed to reach definitive conclusions regarding the findings suggested by this method.

Antiparkinson Agents↗

PubMed2001

Are perceived neighborhood hazards a barrier to physical activity in children?

BACKGROUND: We hypothesized that children's perceptions of more neighborhood hazards would be associated with less physical activity, less aerobic fitness, and a higher body mass index. OBJECTIVE: To examine the association between a hazardous neighborhood context and physical activity in children. METHODS: Fourth-grade students (n = 796) of diverse ethnic and economic backgrounds completed measures of neighborhood hazards, self-reported physical activity, physical fitness, height, and weight. Parents (n = 518) completed telephone interviews and provided data on their education level and occupation. RESULTS: As expected, children from families of lower socioeconomic status perceived significantly more neighborhood hazards. Contrary to our hypothesis, the perception of more hazards was significantly associated with more reported physical activity. This finding was not explained by school heterogeneity, alteration of the hazards measure, or differences in socioeconomic status. CONCLUSION: To further examine the relationship between neighborhood hazards and physical activity, we suggest that future studies include assessments of sedentary behavior, parental fear of violence, parental regulation of children's leisure activities, and cost and quality of available play areas and organized sports.

Acculturation↗

PubMed2001

Supportive-expressive group therapy and distress in patients with metastatic breast cancer: a randomized clinical intervention trial.

BACKGROUND: Metastatic breast cancer carries with it considerable psychosocial morbidity. Studies have shown that some patients with metastatic breast cancer experience clinically significant anxiety and depression and traumatic stress symptoms. Supportive-expressive group psychotherapy was developed to help patients with cancer face and adjust to their existential concerns, express and manage disease-related emotions, increase social support, enhance relationships with family and physicians, and improve symptom control. METHODS: Of 125 women with metastatic breast cancer recruited into the study, 64 were randomized to the intervention and 61 to the control condition. Intervention women were offered 1 year of weekly supportive-expressive group therapy and educational materials. Control women received educational materials only. Participants were assessed at baseline and every 4 months during the first year. Data at baseline and from at least 1 assessment were collected from 102 participants during this 12-month period, and these participants compose the study population. RESULTS: Primary analyses based on all available data indicated that participants in the treatment condition showed a significantly greater decline in traumatic stress symptoms on the Impact of Event Scale (effect size, 0.25) compared with the control condition, but there was no difference in Profile of Mood States total mood disturbance. However, when the final assessment occurring within a year of death was removed, a secondary analysis showed a significantly greater decline in total mood disturbance (effect size, 0.25) and traumatic stress symptoms (effect size, 0.33) for the treatment condition compared with the control condition. CONCLUSION: Supportive-expressive therapy, with its emphasis on providing support and helping patients face and deal with their disease-related stress, can help reduce distress in patients with metastatic breast cancer.

Adaptation, Psychological↗

PubMed2001

The effects of child sexual abuse: Comment on Rind, Tromovitch, and Bauserman (1998).

B. Rind, P. Tromovitch, and R. Bauserman (1998) examined the long-term effects of childhood sexual abuse (CSA) by meta-analyzing studies of college students. The authors reported that effects "were neither pervasive nor typically intense" and that "men reacted much less negatively than women" (p. 22) and recommended value-neutral reconceptualization of the CSA construct. The current analysis revealed numerous problems in that study that minimized CSA-adjustment relations, including use of a healthy sample, an inclusive definition of CSA, failure to correct for statistical attenuation, and misreporting of original data. Rind et al.'s study's main conclusions were not supported by the original data. As such, attempts to use their study to argue that an individual has not been harmed by sexual abuse constitute a serious misapplication of its findings.

Adaptation, Psychological↗

PubMed2001

Do logistic regression and signal detection identify different subgroups at risk? Implications for the design of tailored interventions.

Identifying subgroups of high-risk individuals can lead to the development of tailored interventions for those subgroups. This study compared two multivariate statistical methods (logistic regression and signal detection) and evaluated their ability to identify subgroups at risk. The methods identified similar risk predictors and had similar predictive accuracy in exploratory and validation samples. However, the 2 methods did not classify individuals into the same subgroups. Within subgroups, logistic regression identified individuals that were homogeneous in outcome but heterogeneous in risk predictors. In contrast, signal detection identified individuals that were homogeneous in both outcome and risk predictors. Because of the ability to identify homogeneous subgroups, signal detection may be more useful than logistic regression for designing distinct tailored interventions for subgroups of high-risk individuals.

Adult↗

PubMed2001

Symptom profiles in children with ADHD: effects of comorbidity and gender.

OBJECTIVE: To examine ratings and objective measures of attention-deficit/hyperactivity disorder (ADHD) symptoms to assess whether ADHD children with and without comorbid conditions have equally high levels of core symptoms and whether symptom profiles differ as a function of comorbidity and gender. METHOD: Four hundred ninety-eight children from the NIMH Collaborative Multisite Multimodal Treatment Study of Children With Attention-Deficit/Hyperactivity Disorder (MTA) were divided into comorbid groups based on the parent Diagnostic Interview Schedule for Children and assessed via parents' and teachers' Swanson, Nolan, and Pelham (SNAP) ratings and a continuous performance test (CPT). Comorbidity and gender effects were examined using analyses of covariance controlled for age and site. RESULTS: CPT inattention, impulsivity, and dyscontrol errors were high in all ADHD groups. Children with ADHD + oppositional defiant or conduct disorder were rated as more impulsive than inattentive, while children with ADHD + anxiety disorders (ANX) were relatively more inattentive than impulsive. Girls were less impaired than boys on most ratings and several CPT indices, particularly impulsivity, and girls with ADHD + ANX made fewer CPT impulsivity errors than girls with ADHD-only. CONCLUSIONS: Children with ADHD have high levels of core symptoms as measured by rating scales and CPT, irrespective of comorbidity. However, there are important differences in symptomatology as a function of comorbidity and gender.

Analysis of Variance↗

PubMed2001

ADHD comorbidity findings from the MTA study: comparing comorbid subgroups.

OBJECTIVES: Previous research has been inconclusive whether attention-deficit/hyperactivity disorder (ADHD), when comorbid with disruptive disorders (oppositional defiant disorder [ODD] or conduct disorder [CD]), with the internalizing disorders (anxiety and/or depression), or with both, should constitute separate clinical entities. Determination of the clinical significance of potential ADHD + internalizing disorder or ADHD + ODD/CD syndromes could yield better diagnostic decision-making, treatment planning, and treatment outcomes. METHOD: Drawing upon cross-sectional and longitudinal information from 579 children (aged 7-9.9 years) with ADHD participating in the NIMH Collaborative Multisite Multimodal Treatment Study of Children With Attention-Deficit/Hyperactivity Disorder (MTA), investigators applied validational criteria to compare ADHD subjects with and without comorbid internalizing disorders and ODD/CD. RESULTS: Substantial evidence of main effects of internalizing and externalizing comorbid disorders was found. Moderate evidence of interactions of parent-reported anxiety and ODD/CD status were noted on response to treatment, indicating that children with ADHD and anxiety disorders (but no ODD/CD) were likely to respond equally well to the MTA behavioral and medication treatments. Children with ADHD-only or ADHD with ODD/CD (but without anxiety disorders) responded best to MTA medication treatments (with or without behavioral treatments), while children with multiple comorbid disorders (anxiety and ODD/CD) responded optimally to combined (medication and behavioral) treatments. CONCLUSIONS: Findings indicate that three clinical profiles, ADHD co-occurring with internalizing disorders (principally parent-reported anxiety disorders) absent any concurrent disruptive disorder (ADHD + ANX), ADHD co-occurring with ODD/CD but no anxiety (ADHD + ODD/CD), and ADHD with both anxiety and ODD/CD (ADHD + ANX + ODD/CD) may be sufficiently distinct to warrant classification as ADHD subtypes different from "pure" ADHD with neither comorbidity. Future clinical, etiological, and genetics research should explore the merits of these three ADHD classification options.

Analysis of Variance↗

PubMed2001

Multimodal treatment of ADHD in the MTA: an alternative outcome analysis.

OBJECTIVE: To conduct a post hoc investigation of the utility of a single composite measure of treatment outcome for the NIMH Collaborative Multisite Multimodal Treatment Study of Children With Attention-Deficit/Hyperactivity Disorder (MTA) at 14 months postbaseline. BACKGROUND: Examination of multiple measures one at a time in the main MTA intent-to-treat outcome analyses failed to detect a statistically significant advantage of combined treatment (Comb) over medication management (MedMgt). A measure that increases power and precision using a single outcome score may be a useful alternative to multiple outcome measures. METHOD: Factor analysis of baseline scores yielded two "source factors" (parent and teacher) and one "instrument factor" (parent-child interactions). A composite score was created from the average of standardized parent and teacher measures. RESULTS: The composite was internally consistent (alpha = .83), reliable (test-retest over 3 months = 0.86), and correlated 0.61 with clinician global judgments. In an intent-to-treat analysis, Comb was statistically significantly better than all other treatments, with effect sizes ranging from small (0.28) versus MedMgt, to moderately large (0.70) versus a community comparison group. CONCLUSIONS: A composite of ADHD variables may be an important tool in future treatment trials with ADHD and may avoid some of the statistical limitations of multiple measures.

Analysis of Variance↗

PubMed2001

Clinical relevance of the primary findings of the MTA: success rates based on severity of ADHD and ODD symptoms at the end of treatment.

OBJECTIVES: To develop a categorical outcome measure related to clinical decisions and to perform secondary analyses to supplement the primary analyses of the NIMH Collaborative Multisite Multimodal Treatment Study of Children With Attention-Deficit/Hyperactivity Disorder (MTA). METHOD: End-of-treatment status was summarized by averaging the parent and teacher ratings of attention-deficit/hyperactivity disorder and oppositional defiant disorder symptoms on the Swanson, Nolan, and Pelham, version IV (SNAP-IV) scale, and low symptom-severity ("Just a Little") on this continuous measure was set as a clinical cutoff to form a categorical outcome measure reflecting successful treatment. Three orthogonal comparisons of the treatment groups (combined treatment [Comb], medication management [MedMgt], behavioral treatment [Beh], and community comparison [CC]) evaluated hypotheses about the MTA medication algorithm ("Comb + MedMgt versus Beh + CC"), multimodality superiority ("Comb versus MedMgt"), and psychosocial substitution ("Beh versus CC"). RESULTS: The summary of SNAP-IV ratings across sources and domains increased the precision of measurement by 30%. The secondary analyses of group differences in success rates (Comb = 68%; MedMgt = 56%; Beh = 34%; CC = 25%) confirmed the large effect of the MTA medication algorithm and a smaller effect of multimodality superiority, which was now statistically significant (p < .05). The psychosocial substitution effect remained negligible and nonsignificant. CONCLUSION: These secondary analyses confirm the primary findings and clarify clinical decisions about the choice between multimodal and unimodal treatment with medication.

Attention Deficit Disorder with Hyperactivity↗

PubMed2001

Impairment and deportment responses to different methylphenidate doses in children with ADHD: the MTA titration trial.

OBJECTIVE: Results of the NIMH Collaborative Multisite Multimodal Treatment Study of Children With Attention-Deficit/Hyperactivity Disorder (MTA) were analyzed to determine whether a double-blind, placebo-controlled methylphenidate (MPH) titration trial identified the best MPH dose for each child with attention-deficit/hyperactivity disorder (ADHD). METHOD: Children with ADHD assigned to MTA medication treatment groups (n = 289) underwent a controlled 28-day titration protocol that administered different MPH doses (placebo, low, middle, and high) on successive days. RESULTS: A repeated-measures analysis of variance revealed main effects for MPH dose with greater effects on teacher ratings of impairment and deportment (F3 = 100.6, n = 223, p = .0001; effect sizes 0.8-1.3) than on parent ratings of similar endpoints (F3 = 55.61, n = 253, p = .00001; effect sizes 0.4-0.6). Dose did not interact with period, dose order, comorbid diagnosis, site, or treatment group. CONCLUSIONS: The MTA titration protocol validated the efficacy of weekend MPH dosing and established a total daily dose limit of 35 mg of MPH for children weighing less than 25 kg. It replicated previously reported MPH response rates (77%), distribution of best doses (10-50 mg/day) across subjects, effect sizes on impairment and deportment, as well as dose-related adverse events.

Analysis of Variance↗

PubMed2001

Effects of reducing television viewing on children's requests for toys: a randomized controlled trial.

Previous attempts to reduce the effects of television advertising on children's purchase requests have had little success. Therefore, we tested the effects of a classroom intervention to reduce television, videotape, and video game use on children's toy purchase requests, in a school-based randomized controlled trial. Third- and fourth-grade children (mean age, 8.9 years) in two sociodemographically and scholastically matched public elementary schools were eligible to participate. Children in one randomly selected elementary school received an 18-lesson, 6-month classroom curriculum to reduce television, videotape, and video game use. In both schools, in September (before intervention) and April (after intervention) of a single school year, children and parents reported children's prior week's purchase requests for toys seen on television. After intervention, children in the intervention school were significantly less likely to report toy purchase requests than children in the control school, with adjusting for baseline purchase requests, gender, and age (odds ratio, 0.29; 95% confidence interval, 0.12-0.69). Among intervention school children, reductions in self-reported purchase requests were also associated with reductions in television viewing. There was no significant difference between schools in parent reports of children's requests for toy purchases. These findings suggest that reducing television viewing is a promising approach to reducing the influences of advertising on children's behavior.

Advertising↗

PubMed2001

How do risk factors work together? Mediators, moderators, and independent, overlapping, and proxy risk factors.

OBJECTIVE: The authors developed a methodological basis for investigating how risk factors work together. Better methods are needed for understanding the etiology of disorders, such as psychiatric syndromes, that presumably are the result of complex causal chains. METHOD: Approaches from psychology, epidemiology, clinical trials, and basic sciences were synthesized. RESULTS: The authors define conceptually and operationally five different clinically important ways in which two risk factors may work together to influence an outcome: as proxy, overlapping, and independent risk factors and as mediators and moderators. CONCLUSIONS: Classifying putative risk factors into these qualitatively different types can help identify high-risk individuals in need of preventive interventions and can help inform the content of such interventions. These methods may also help bridge the gaps between theory, the basic and clinical sciences, and clinical and policy applications and thus aid the search for early diagnoses and for highly effective preventive and treatment interventions.

Causality↗

PubMed2001

Apolipoprotein E epsilon4 allele affects the relationship between stress and depression in caregivers of patients with Alzheimer's disease.

We examined the effect of the apolipoprotein E (apo E) epsilon4 allele on the relationship between self-reported stress and mood in caregivers of patients with Alzheimer's disease. Eighty-six female subjects between the ages of 28 and 82 years who were community-dwelling AD patient caregivers participated in the study. A cross-sectional analysis of stress and mood was performed using the Revised Memory and Behavior Problem Checklist and the Geriatric Depression Scale. All subjects were evaluated for normal cognitive function (Mini-Mental Status Examination) and apo E genotype. The results indicated that increased levels of stress were associated with increased levels of depressive symptoms in nondemented caregivers with the epsilon4 allele. This relationship was not observed in caregivers without the epsilon4 allele. These results suggest that carriers of the epsilon4 allele may respond differently to psychological stress than do individuals without the epsilon4 allele.

Adult↗

PubMed2001

Can methodological features account for patient-treatment matching findings in the alcohol field?

OBJECTIVE: Despite enthusiasm for the potential of matching patients to alcohol treatments to improve outcomes, consistent findings have not emerged. This review considers the extent to which methodological factors may account for the pattern of findings from research on Patient x Alcohol Treatment interactions. METHOD: We focused on 55 studies that compared more than one type of alcohol treatment and included formal statistical tests for interactions. We examined four predictors of the number of significant interactions found in the 55 studies: (1) the number of statistical tests for interactions conducted, (2) the average number of participants, (3) whether or not participants were randomized to treatment and (4) the proportion of tested interactions that were hypothesis- or rationale-driven, as opposed to exploratory. RESULTS: Only the number of statistical tests for interactions predicted the number of patient-treatment interactions identified per study (zero-order r = 0.47; r2 = 0.22). A substantial number of tests for interactions (43) was conducted, on average, per study. Only a minority of the studies (33%) included enough participants to have a reasonable probability (0.80) of identifying a medium-sized matching effect. CONCLUSIONS: Drawing general conclusions regarding matching patients to alcohol treatments is hampered because Type I error has contributed to the matches identified, studies in this area are often underpowered, and the combinations of patient and treatment variables that have been tested are few relative to the numerous possible combinations. To be productive, future research will need to focus on patients at the extremes of matching dimensions and on distinct treatments. (J Stud. Alcohol 62: 62-73, 2001)

Alcoholism↗

PubMed2000

Diurnal cortisol rhythm as a predictor of breast cancer survival.

BACKGROUND: : Abnormal circadian rhythms have been observed in patients with cancer, but the prognostic value of such alterations has not been confirmed. We examined the association between diurnal variation of salivary cortisol in patients with metastatic breast cancer and subsequent survival. We explored relationships between cortisol rhythms, circulating natural killer (NK) cell counts and activity, prognostic indicators, medical treatment, and psychosocial variables. METHODS: Salivary cortisol levels of 104 patients with metastatic breast cancer were assessed at study entry at 0800, 1200, 1700, and 2100 hours on each of 3 consecutive days, and the slope of diurnal cortisol variation was calculated using a regression of log-transformed cortisol concentrations on sample collection time. NK cell numbers were measured by flow cytometry, and NK cell activity was measured by the chromium release assay. The survival analysis was conducted by the Cox proportional hazards regression model with two-sided statistical testing. RESULTS: Cortisol slope predicted subsequent survival up to 7 years later. Earlier mortality occurred among patients with relatively "flat" rhythms, indicating a lack of normal diurnal variation (Cox proportional hazards, P =. 0036). Patients with chest metastases, as opposed to those with visceral or bone metastases, had more rhythmic cortisol profiles. Flattened profiles were linked with low counts and suppressed activity of NK cells. After adjustment for each of these and other factors, the cortisol slope remained a statistically significant, independent predictor of survival time. NK cell count emerged as a secondary predictor of survival. CONCLUSIONS: Patients with metastatic breast cancer whose diurnal cortisol rhythms were flattened or abnormal had earlier mortality. Suppression of NK cell count and NK function may be a mediator or a marker of more rapid disease progression.

Adult↗

PubMed2000

Use of placebo control groups in evaluating efficacy of treatment of unipolar major depression.

Double-blind, random-assignment placebo-controlled trials are routinely used in evaluating efficacy of potential antidepressant agents. In recent years concern has risen that placebo response rates in unipolar depression are too high, and this has eroded confidence in both old and new agents. At the same time, the use of placebos has been questioned by patients and their advocates. We review factors that have been commonly explored as associated with placebo response (e.g., length of episode, severity, subtype), as well as issues in methodology (e.g., interrater reliability, statistical artifacts). We discuss possible methods of dealing with the problem of placebo response, emphasizing reconceptualizing effect sizes to design more powerful single trials and a systematic sequence of trials to achieve the right answers.

Antidepressive Agents↗