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Biomedical subjects

D K Ahern

Publications and source records attributed to D K Ahern.

33 records · Page 2Linked to original sources
PubMed1990

Interdisciplinary perspectives on mechanisms and management of low back pain.

Chronic low back pain (CLBP) is one of the most pervasive and costly problems facing medicine today. In addition to personal suffering, CLBP accounts for a greatly disproportionate amount of consumer health care over-utilization, employee absenteeism, lowered work productivity, disability and compensation payments. Recent research in the area has called attention to the complex nature of the problem and the need for an interdisciplinary approach to identification and management. Toward this end, a panel of health care professionals with skill in the assessment and treatment of chronic pain was convened on November 17, 1988. Sponsored by the Institute for Behavioral Medicine in Providence and with funding from the National Institute for Neurological Disorders and Stroke, Stroke and Trauma Program, the purpose of the panel discussion was to bring together clinicians and researchers from distinctly different specialties but who all work with CLBP patients. Topics of discussion included etiology, current status of medical diagnostics and treatments for chronic pain, conceptual and systems issues, and directions for future research.

Back Pain↗
PubMed1988

Psychological distress as a predictor of ventricular arrhythmias in a post-myocardial infarction population.

A prospective study examining the relationship between psychological distress and ventricular ectopy was conducted with 125 post-myocardial infarction patients equipped with a transtelephonic ECG monitor. Subjects were subsequently grouped according to the occurrence (n = 59) or nonoccurrence (n = 65) of ventricular arrhythmias over a 1-year period. Results indicated a direct relationship between self-reported distress levels and occurrence of ectopic beats. This relationship was unaltered by adjusting simultaneously for known predictors of arrhythmias, including cardiac risk, age, and the prescription of beta-blocker agents. Thus this study represents an initial demonstration in a post-myocardial infarction population that psychosocial factors have prognostic significance for arrhythmias and, presumably, sudden death.

Arrhythmias, Cardiac↗
PubMed1988

Chronic pain and functional impairment: assessing beliefs about their relationship.

Many chronic pain patients believe that they cannot function normally because of their pain. The Pain and Impairment Relationship Scale (PAIRS) was developed to assess the extent to which chronic pain patients endorse this belief, and the relationship of this belief to functional impairment, measured both subjectively and objectively. The PAIRS was administered to 56 patients in a chronic pain treatment program. The PAIRS demonstrated adequate internal consistency and it correlated significantly with another measure of the cognitive component of chronic pain syndrome, the Cognitive Errors Questionnaire--Low Back Scale. The PAIRS accounted for a significant proportion of variance in several measures of impairment (including the Sickness Impact Profile, restrictions in range of motion, and statements of limitation during a standardized exercise routine) beyond that accounted for solely by subjective pain estimate in multiple regression analyses. It appears that the belief that pain necessarily implies disability is associated with actual impairment, independent of the actual contribution of reported pain.

Adult↗
PubMed1986

Reliability of lumbar paravertebral EMG assessment in chronic low back pain.

The reliability of lumbar paravertebral EMG assessment was investigated in a sample of 70 patients with chronic low back pain, (CLBP). Dual-site EMG monitoring was employed during both static postures and movements. Flexion and rotation indices were divided to assess the reliability of patterning of paravertebral EMG during movement. Within-session reliabilities computed for the full sample ranged from 0.66 to 0.97, and between-session reliabilities, computed on a subset of 29 patients retested after varying intervals, ranged from 0.26 to 0.92. Average EMG levels, flexion, and rotation indices showed no statistically significant differences between surgical (n = 40) and nonsurgical patients (n = 30), although EMG variability was consistently greater for surgical patients across the postures and movements. These results indicate that lumbar paravertebral EMG can be reliably measured and therefore has potential utility as an assessment and treatment variable in CLBP.

Adult↗
PubMed1985

Development of an audiovisual taxonomy of pain behavior: reliability and discriminant validity.

This article represents the final stages in the development of a pain behavior taxonomy that was empirically derived from patients', spouses', and health care providers' nominations of pain behaviors. Seventy-one chronic low back pain patients and 40 controls were videotaped while undergoing a structured sequence of movements involving sitting, standing, walking, bending, and exercising, and a brief standardized interview component. Two independent observers rated each subject's videotape employing a 16-category observational rating system that included both verbal and nonverbal pain behaviors. Seven of the pain behavior categories, including guarding, bracing, position shifts, partial movement, grimacing, limitation statements, and sounds, had acceptable reliabilities and frequencies and were therefore selected for inclusion in a discriminant analysis. The subject sample was randomly divided into two equal groups, and a stepwise discriminant function analysis on the first subsample indicated that partial movement, limitation statements, sounds, and position shifts accounted for 75% of the variance in group membership and correctly classified 94.4% of the patients and 95.2% of the controls. On cross-validation, the same four categories identified in the initial discriminant function correctly classified 88.9% of the subjects in the second subsample. The utility of this pain behavior observational recording system is discussed in reference to both patient assessment and treatment outcome research.

Adult↗
PubMed1985

Life-events and psychological disturbance in chronic low back pain.

Stressful life-events have been identified as contributing to psychological disturbance in chronic low back pain (CLBP). However, previous research has focused on the presence versus absence of generalized distress and failed to distinguish between positive and negative events. The present study examined the relationship of positive and negative life-events to various aspects of distress as measured by the eight clinical scales of the MMPI. Negative life-events were found to be associated primarily with depression and social maladjustment, while positive events were inversely related to somatic concern.

Adult↗
PubMed1985

Chronic pain: electromechanical recording device for measuring patients' activity patterns.

Many authors have recommended the development and use of automated recording devices as alternatives to self-report measures of activity patterns in chronic pain patients. An electromechanical device is described that can be used to measure downtime or uptime in chronic pain patients. This monitor has several advantages over mercury tilt-switch devices including freedom from plane dependence, resistance to artifact associated with rapid or vigorous movements, and the flexibility to permit conceptualization of sitting time as either uptime or downtime, depending upon placement of the position switch. The monitor consists of a miniature electronic timer, a switching delay circuit and battery pack, an electromechanical position switch, a belt with carrying cases, and a battery recharger. The device has high reliability (agreement coefficients of 1.0) and concurrent validity (r = 0.99) for both downtime and uptime assessments. Research applications and clinical use of this device are discussed as well as directions for the further development of automated recording devices.

Chronic Disease↗
PubMedDate not supplied

Differential diagnosis of palpitations. Preliminary development of a screening instrument.

OBJECTIVE: To develop a self-report screening instrument to assist in the differential diagnosis of medical outpatients complaining of palpitations. DESIGN: Patients completed self-report questionnaires assessing somatization, cardiac symptoms, and hypochondriacal concerns about health. Principal components analysis was performed to identify a subset of questions that could be used to distinguish patients with palpitations who have panic disorder from those with palpitations who do not have panic disorder. PATIENTS: Sixty-seven medical outpatients referred for Holter monitoring because of a complaint of palpitations. MAIN OUTCOME MEASURES: Patients with palpitations were classified into 2 groups, those with and those without current panic disorder (established with a structured, diagnostic interview). The sensitivity, specificity, and posttest probability of the screening instrument were determined. RESULTS: A reliable, stable, 10-item instrument was derived. It seems to tap diffuse, vague, or generalized somatic complaints and worry about physical illness. With the use of a criterion cutoff score of 21, this instrument had a sensitivity of 0.81, a specificity of 0.80, and a post-test probability of.57 in detecting current panic disorder in patients with palpitations. CONCLUSIONS: A psychometrically sound and brief self-report instrument was developed to assist in the differential diagnosis of palpitations. It can be used to identify patients whose symptoms are more likely to result from panic disorder and in whom ambulatory monitoring might be deferred.

Adult↗
PubMedDate not supplied

Predictors of remission in DSM hypochondriasis.

Although hypochondriasis is generally believed to be a chronic and refractory disorder, relatively little is known about its natural history and course. Based on a cognitive/perceptual model of hypochondriasis, we hypothesized that the disorder would be more chronic in patients who both amplify benign bodily symptoms and tend to attribute them to disease. Thirty-eight patients with DSM hypochondriasis were assessed with a structured, diagnostic interview and self-report questionnaire. A logistic regression model containing sociodemographic characteristics and a 3-way interaction term composed of the tendency to amplify bodily sensations, the tendency to attribute common symptoms to disease, and somatization (all measured at inception) correctly classified the remission status of 81.6% of the patients at follow-up 4 years later. These results suggest that patients who somatize, who are amplifiers of bodily sensation, and those who tend to attribute ambiguous symptoms to disease have more chronic and more refractory hypochondriasis. It is the co-occurrence of these cognitive and perceptual characteristics, rather than their occurrence individually, which predicts the persistence of this disorder.

Adaptation, Psychological↗
PubMedDate not supplied

Somatic style and symptom reporting in rheumatoid arthritis.

The authors studied the relative contributions of psychological characteristics and rheumatoid arthritis (RA) morbidity to RA symptoms and medication side effects. Thirty-one consecutive patients attending an RA clinic completed self-report questionnaires and diaries assessing RA symptoms and somatic style, a constellation of beliefs, attitudes, and concerns about disease and health. After 3 months, the patients were assessed for RA symptoms and self-reported medication side effects. At inception, RA symptoms were associated with several components of somatic style. At 3-month follow-up, changes in RA symptoms and the incidence of medication side effects were predicted by somatic style variables measured at inception. The symptoms of RA and the side effects of RA pharmacotherapy are prospectively predicted by somatic style as well as by the severity and extent of RA.

Adult↗
PubMedDate not supplied

Palpitations and cardiac awareness after heart transplantation.

OBJECTIVE: The aim of this study was to examine the awareness of resting heartbeat in heart transplantation recipients, compare it with that found in other medical populations, and determine whether clinical characteristics are associated with accurate heartbeat awareness. METHODS: Eligible patients underwent a research battery consisting of a heartbeat detection task and self-report questionnaires assessing cardiac symptoms, psychosocial variables, and cognitive function. The accurate awareness of resting heartbeat was determined by presenting the patients with auditory stimuli at each of six different delays following the R wave on the ECG. Patients then selected the tones that they thought coincided with the sensation they had of their heart beating. The patients' physicians rated their cardiac morbidity. The results were contrasted with comparable data obtained in previous work with other ambulatory medical populations. RESULTS: Forty-one consecutive heart transplantation recipients who survived for at least 3 months after surgery were eligible. Thirty-four (82.9%) of them were studied and complete data were obtained on 26 (63.4%). Nine patients (34.6%) were reliably able to detect their resting heartbeat. When compared with the 17 patients who were not accurately aware of their heartbeat, the two groups did not differ significantly in cardiac morbidity, cognitive brain dysfunction, generalized psychiatric distress, depression, somatization, or hypochondriacal attitudes. A significantly higher proportion of heart transplantation recipients were accurately aware of their heartbeat than was found in a sample of general medical outpatients and in asymptomatic, nonpatient volunteers. CONCLUSIONS: One-third of heart transplant recipients are accurately aware of resting heartbeat, despite the absence of cardiac innervation.

Adult↗
PubMedDate not supplied

Selected topics in statistical analysis of clinical research.

Statistical analysis usually is employed in the evaluation of clinical research studies. This paper reviews and makes recommendations in three areas frequently overlooked in the conduct of clinical research: power analysis, specification of a priori research hypotheses, and Bayesian analysis. Power analysis determines the number of subjects required to conduct a meaningful study and should be performed during the planning phase. Research and null hypotheses are essential elements of research design and should be specified prior to statistical analysis. Bayesian analysis can be used both to evaluate diagnostic tests and as an alternative to traditional statistical approaches for testing multiple hypotheses. Application of these methods is described and clinical examples are provided. The discussion is nontechnical and is directed toward the clinical researcher.

Aged↗