Search PubMedSearch

Biomedical subjects

G R Parkerson

Publications and source records attributed to G R Parkerson.

At least 19 recordsLinked to original sources

Recognition of a small number of diverse epitopes dominates the cytotoxic T lymphocytes response to HIV type 1 in an infected individual.

Mitogen-activated T cell lines may be reproducibly used to identify relatively conserved HIV-1 epitopes that dominate CTL recognition of HIV-infected cells. Using a combination of nested truncations of HIV-vaccinia recombinants encoding HIV-1LAI Env and overlapping peptides that span the coding regions of the HIV-1 SF2 subclone of env, gag, nef, rev, and tat, we have mapped the immunodominant, relatively conserved CTL epitopes recognized by 25 HIV-seropositive individuals with CD4 counts between 100 and 500/mm3 and no history of AIDS opportunistic infection. We could characterize at least 1 peptide CTL epitope recognized by the T cell lines of 18 of 25 of the subjects; the T cell lines from 2 additional subjects recognized HIV-vaccinia presenting targets, but no dominant peptide epitope was identified. CTL epitopes were most frequently encoded by gag (recognized by 16 of 25 patient T cell lines), followed by nef and env (11 of 25 each), and the RT region of pol (9 of 25). Tat and Rev were rarely the sites of CTL epitopes. The identified epitopes occurred predominantly in relatively conserved regions of HIV-1. The mean number of HIV peptides identified at a single time for each cell line was 2.7 +/- 1.7. Although no single peptide dominated CTL recognition in more than four individuals, clusters of epitopes were found in the N-terminal region of gp160 and in two central regions of Nef. The dominant HIV-1 CTL epitopes in infected patients were not predictable on the basis of MHC expression and varied widely in an MHC-diverse population.

Amino Acid Sequence

Screening for anxiety and depression in primary care with the Duke Anxiety-Depression Scale.

BACKGROUND AND OBJECTIVES: Anxiety and depression are highly prevalent and underdiagnosed in primary care. This study tested the seven-item Duke Anxiety-Depression Scale (DUKE-AD) in primary care adult patients as a screener for anxiety and depression as defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R). METHODS: Receiver operating characteristic curves (ROC) and odds ratios were used to test screener accuracy, and sensitivities and specificities were used to test screener efficiency in patients with anxiety and/ or depression. RESULTS: In 481 patients, the ROC area for patients with major anxiety disorders (panic disorder, agoraphobia, or generalized anxiety) was 72.3%. The ROC area for major depressive disorders (major depressive disorder and/or dysthymia) was 78.3%, and the ROC area for both major anxiety and/or depressive disorders was 76.2%. Odds ratios for these same groups after controlling for sociodemographic factors were 1.043, 1.057, and 1.053, respectively. Sensitivities and specificities for these groups at the DUKE-AD score cutoff point of > 30 on a 0-100 scale were 71.4% and 59.2%, 81.8% and 63.6%, and 73.9% and 66.1%, respectively. CONCLUSIONS: The DUKE-AD is a brief, easily scored questionnaire that serves as a valid screener for DSM-III-R anxiety and depression in the primary care setting.

Adolescent

Anxiety and depressive symptom identification using the Duke Health Profile.

Duke Health Profile (DUKE) subscales were compared for their ability to identify anxiety and depressive symptoms as measured by the State Anxiety Inventory (SAI) and the Center for Epidemiologic Studies Depression Scale (CES-D) in 413 primary care patients. The seven-item Duke Anxiety-Depression Scale (DUKE-AD) was the best symptom identifier, with sensitivities and specificities greater than 70% for high scores on both the SAI and CES-D. Also, baseline DUKE-AD scores predicted five clinical outcomes during an 18-month follow-up period, with receiver operating characteristic (ROC) curve areas ranging from 57.1 to 58.7%. Patients shown by DUKE-AD scores to be at high risk (>30, scale 0-100) for symptoms of anxiety and/or depression were more often women, less well-educated, not working, and with lower socioeconomic status. The severity of illness was higher than that of low-risk patients. Although the providers did not know which patients were at high risk, they made a clinical diagnosis of anxiety or depression more often in high-risk patients.

Adolescent

Classification of severity of health problems in family/general practice: an international field trial.

BACKGROUND: A methodology is needed for classification of health problems by severity. OBJECTIVES: We aimed to test the Duke Severity of Illness Checklist (DUSOI) for feasibility and usefulness. METHOD: The DUSOI was field tested internationally by 22 family/general practitioners in 9 countries. RESULTS: The DUSOI was found to be feasible for rating severity of illness of health problems in family/general practice. The measure was shown to be clinically useful in older patients and those with chronic and more severe health problems. Variability of severity ratings was less within the same rater than between different raters (i.e. higher intrarater than interrater reliability). Clinical face validity was supported by the finding that DUSOI ratings classified patients with the same diagnosis and those with different diagnoses according to the severity differences that would be expected clinically. CONCLUSIONS: Although research is needed to improve reliability and to test validity further, the DUSOI was shown in the present study to be a methodology that is reasonable for consideration as an international classification of health problems by their severity in primary care patients.

Adolescent

Perceived family stress as a predictor of health-related outcomes.

OBJECTIVE: To measure the predictive effect of patient-perceived family stress for health-related outcomes. DESIGN: Prospective study of patients whose social stress and support were measured by self-report at baseline with the Duke Social Support and Stress Scale and used as predictors of outcomes during an 18-month follow-up period. SETTING: Rural primary care community health clinic. PATIENTS: Convenience sample of ambulatory adults. INTERVENTION: None. MAIN OUTCOME MEASURES: Follow-up (one or more follow-up visits), frequent follow-up (more than six visits), referral and/or hospitalization (one or more), high follow-up severity of illness (upper-tertile mean Duke Severity of Illness Checklist scores), and high follow-up total charges (> or = $268). RESULTS: There were 413 patients with a mean age of 40.4 years. Of these, 58.6% were women; 47.2%, African American; 52.8%, white; 56.7%, married; 77.2%, wage earners or housekeepers; and 52.3% had more than one health problem. At baseline, patients with high self-reported family stress (upper-tertile Duke Social Support and Stress Scale scores) had lower quality of life, functional health, and social support scores and higher dysfunctional health and social stress scores than other patients. High baseline family stress scores (scale of 0 to 100) predicted follow-up (odds ratio [OR] = 1.014), frequent follow-up (OR = 1.021), referral and/or hospitalization (OR = 1.018), high severity of illness at follow-up (OR = 1.016), and high follow-up charges (OR = 1.018) after controlling for the effects of social support, age, gender, and race. Family stress scores were stronger predictors of these outcomes than the other social stress and support variables. CONCLUSION: The finding of patient-perceived family stress as a risk factor for unfavorable health-related outcomes suggests the need for early detection and treatment of family stress by family physicians.

Adult

Health status and severity of illness as predictors of outcomes in primary care.

Two measures of health status and severity of illness were tested as indicators of patient case-mix to predict health-related outcomes in a rural primary care community health clinic, using a convenience sample of 413 ambulatory adults (mean age = 40.4 years: 58.6% women, and 47.2% black). At baseline; patients completed the Duke Health Profile, and providers completed the Duke Severity of Illness Checklist. During the 18-month follow-up study, patients experienced the following outcomes: at least one follow-up visit (74.3%), more than six visits (20.6%), at least one referral or hospital admission (17.3%), upper tertile severity scores (24.9%), and upper tertile office charges (24.9%). Baseline physical health, perceived health, and severity scores were statistically significantly predictive of all five outcomes. Predictive accuracy (i.e., area under the receiver operating characteristic curves) for outcome probabilities estimated from a case-mix model of physical health, severity, age, gender, and race was 72.3% for follow-up, 69.7% for frequent follow-up, 70.5% for referral and/or hospital stay, 65.7% for high follow-up severity of illness, and 67.6% for high follow-up charges. These data support health status and severity of illness as case-mix indicators and outcome predictors of follow-up utilization, severity of illness, and cost in the primary care setting.

Adult

Feasibility and potential clinical usefulness of a computerized severity of illness measure.

OBJECTIVE: To assess the feasibility and potential clinical usefulness of the computerized Duke Severity of Illness Checklist (DUSOI). DESIGN: Cross-sectional study of patients whose severity of illness was measured with the DUSOI. Providers assessed the clinical usefulness of the DUSOI and recorded the length of time required for rating severity. Auditors rated severity using progress note information. Demographic and financial data from clinic records were also obtained. SETTING: University-based family practice clinic with 64,621 annual visits. PATIENTS: Convenience sample of ambulatory patients. MAIN OUTCOME MEASURES: Clinical usefulness and time required to rate severity. RESULTS: For 117 patients (63.3% female; mean age, 46.3 years), the mean charge was $105.38, the mean number of health problems was 2.0, the mean overall provider DUSOI score was 33.7, and the mean auditor DUSOI score was 34.0 (scale = 0 to 100). There was excellent agreement between provider and auditor DUSOI scores (intraclass correlation coefficient, .77). Providers required 1.1 minutes to record severity; the principal auditor required 1.6 minutes. Providers found the DUSOI potentially useful in 30.3% of patients. Usefulness was greater in women (38.2% of women vs 18.2% of men), older patients (mean age, 54.5 years in useful group vs 41.9 in nonuseful group), and sicker patients (mean DUSOI score, 55.1 vs 25.9). The DUSOI was more clinically useful in patients with health problems such as type II diabetes mellitus (75.0%) than in those with problems such as tobacco use (25.0%). Higher charges correlated with a higher number of health problems and with female gender but not with severity scores. CONCLUSIONS: The computerized DUSOI is feasible for all patients and is potentially useful for women, older, and sicker patients.

Adolescent

The Duke Severity of Illness Checklist (DUSOI) for measurement of severity and comorbidity.

The Duke Severity of Illness Checklist (DUSOI) was evaluated on 414 primary care adult patients using data collected both by medical providers at the time of the patient visit and later by a chart auditor. Severity scores for individual diagnoses were determined by summing the ratings for four non-disease-specific parameters: symptom level, complications, prognosis without treatment, and expected response to treatment. Mean diagnosis severity scores (scale 0-100) among the 21 most prevalent diagnoses varied from a low of 13.9 for menopausal syndrome to a high of 43.0 for sprains and strains. An overall severity score was calculated by combining diagnosis severity scores and giving highest weights to the most severe diagnoses. Provider-generated overall severity scores (mean = 43.3) and auditor-generated overall severity scores (mean = 38.9) were significantly correlated (coefficient of agreement = 0.59, p < 0.0001). Diagnoses varied in their individual contribution to the overall severity score, from 8.9% for lipid disorder to 90.0% for sprains and strains. Separate comorbidity severity scores were calculated to measure the severity of all of each patient's health problems except the diagnosis under study. For example, patients with menopausal syndrome had co-existing health problems which generated a high mean comorbidity severity score of 43.2, while patients with sprains and strains had a low mean comorbidity score of 4.7. The DUSOI Checklist can be used in the clinical setting by both providers and auditors to produce quantitative severity scores (by diagnosis, overall, and for comorbidity) which are based entirely upon clinical judgment. This method should be useful in controlling for severity of illness in clinical studies and indicating the outcome of medical care in terms of reduction in severity of illness following medical interventions.

Adolescent

Disease-specific versus generic measurement of health-related quality of life in insulin-dependent diabetic patients.

The health-related quality of life of 170 adult insulin-dependent diabetic patients was measured cross-sectionally to compare a disease-specific instrument, Diabetes Quality of Life (DQOL) questionnaire, and two generic instruments, the Duke Health Profile (DUKE) and the General Health Perceptions Questionnaire (GHP). The generic measures provided as much or more information about health-related quality of life as the disease-specific instrument. This was demonstrated both by comparison of the DQOL with the DUKE and GHP and by comparison of the disease-specific with the generic components of a modified version of the DQOL. Patients with the diabetic complication of nephropathy had increased worry over their health and lower general health perceptions. Neither the duration of diabetes nor the intensity of insulin therapy, however, was found to have a statistically significant effect on any of the health-related quality of life scores. Nondiabetic factors, such as the comorbidity, nondiabetic medications, marital status, social relationships, and family arguments were found to be predictors of health-related quality of life more often than the diabetic factors duration of diabetes, complications, and intensity of insulin therapy. These analyses suggest the clinical value of using generic questionnaires to measure health-related quality of life and psychosocial factors to identify nondiabetic problems that might respond to intervention, thereby potentially enhancing the effect of diabetes-specific therapy.

Adolescent

Quality of life and functional health of primary care patients.

Quality of life and functional health were measured cross-sectionally for 314 adult ambulatory primary care patients in a rural clinic and found to be much better for patients with low severity of illness who required no confinement to home because of health problems, than for patients with high severity of illness who required confinement. Severity of illness was the strongest predictor for patient-reported physical health function and for patient quality of life when assessed by the health provider. Confinement was the strongest predictor for patient quality of life when assessed by the patient. There was very little agreement between patient-assessed and provider-assessed quality of life. Family stress was the strongest predictor of function in terms of mental health, social health, general health, self-esteem, anxiety, and depression. These data suggest that clinicians should direct increased attention to patient-assessed quality of life, patient-reported functional health status, and psychosocial factors such as family stress in an effort to improve medical outcomes.

Activities of Daily Living

Development of the 17-item Duke Health Profile.

The 17-item Duke Health Profile (DUKE) was developed as a refined version of the 63-item Duke-UNC Health Profile (DUHP) using a methodology based upon a balanced clinical and statistical rationale. The result is a brief, valid functional health measure with 10 scales that compares well with the MOS Short-form and the COOP Charts. In addition to the five constructs (ambulation, emotional symptoms, activities with friends or relatives, health perception, and pain) which are measured by all three of the instruments, the DUKE quantitates cognition, social self-esteem, confinement, and somatic symptoms other than pain.

Adult

Validation of the Duke Social Support and Stress Scale.

The Duke Social Support and Stress Scale (DUSOCS) was validated in 249 adult family practice patients using the Family Strengths, the Family Inventory of Life Events, and the Duke Health Profile (DUKE) as comparison instruments. Validity was supported in that the DUSOCS family support measure had the clinically expected positive associations with DUKE health measures (regression coefficients of +7.4 to +18.7) and negative associations with DUKE anxiety and depression measures (-2.0 to -17.2). DUSOCS family stress had negative associations with the health measures (-11.6 to -34.5) and positive associations with anxiety and depression (+18.9 to +32.1). Family and non-family stress contributed more than severity of illness to elevated levels of anxiety and depression and lowered levels of mental health, social health, and self-esteem, while these same stresses contributed only half as much as severity of illness to lowered physical health.

Adolescent

The health status and life satisfaction of first-year medical students.

The self-reported health status and life satisfaction of 286 first-year Duke University medical students in four consecutive classes were measured at the beginning and end of the school year and compared statistically with relevant sociodemographic and behavioral factors. Health status, quantitated in terms of Duke Health Profile scores, was generally lower for women than for men. Although there was a definite trend of worsening along all parameters of health and satisfaction during the year for both women and men, the most marked change was the increase in depressive symptoms. The students who were very satisfied with life had fewer symptoms of depression and anxiety; higher self-esteem, better physical, mental, and social health; stronger social ties; more physical activity; more sleep; and fewer stressful life events. Strong social ties was the factor most positively related to better health and life satisfaction.

Depressive Disorder

The Duke Health Profile. A 17-item measure of health and dysfunction.

The Duke Health Profile (DUKE) is a 17-item generic self-report instrument containing six health measures (physical, mental, social, general, perceived health, and self-esteem), and four dysfunction measures (anxiety, depression, pain, and disability). Items were derived from the 63-item Duke-UNC Health Profile, based upon face validity and item-remainder correlations. The study population included 683 primary care adult patients. Reliability was supported by Cronbach's alphas (0.55 to 0.78) and test-retest correlations (0.30 to 0.78). Convergent and discriminant validity were demonstrated by score correlations between the DUKE and the Sickness Impact Profile, the Tennessee Self-Concept Scale, and the Zung Self-Rating Depression Scale. Clinical validity was supported by differences between the health scores of patients with clinically different health problems. Patients with painful physical problems had a DUKE physical health mean score of 58.1, while patients with only health maintenance problems had a mean score of 83.9 (scale: 0.0 = poorest health and 100.0 = best health). Patients with mental health problems had a DUKE mental health mean score of 49.2, in contrast to 75.7 for patients with painful physical problems and 79.2 for those with health maintenance. The DUKE is presented as a brief technique for measuring health as an outcome of medical intervention and health promotion.

Adolescent

Associations among family support, family stress, and personal functional health status.

The self-reported family support and stress of 249 ambulatory adult patients, aged 18-49 years, were studied relative to their self-reported functional health. Support from family members was found to be related positively with emotional function. Stress from family members was associated negatively with symptom status, physical function, and emotional function. Patients' severity of illness was related negatively to their symptom status, physical function, and social function, but not to their emotional function. During the study a new self-report instrument, the Duke Social Support and Stress Scale (DUSOCS), was developed to measure family and non-family support and stress. Also, a new chart audit methodology, the Duke Severity of Illness Scale (DUSOI), was designed to assess severity in the ambulatory setting. Reliability and validity of the DUSOCS and the DUSOI were supported. The importance of the patient's perception of health and its family determinants is emphasized.

Adolescent

The effect of a telephone family assessment intervention on the functional health of patients with elevated family stress.

A randomized trial of a telephone family assessment intervention was conducted during a 2.5 month period on 224 ambulatory primary care patients, aged 18-49 years, who were selected according to self-report of elevated family stress levels. Family physicians conducted telephone interviews to collect information from patients on their supportive and stressful family members. The working hypothesis was that this process would lead to reduction in the patient's family stress and to improvement in family support and personal health status. Patients reported that the intervention caused them to think about their family support and helped them to feel better. Comparison of family factor and functional health scores before and after intervention also indicated a limited beneficial effect, but only for a small subset of black patients. These results suggest that the telephone family assessment alone is inadequate as an intervention and should be strengthened to include professional assistance to patients for the family problems that are identified by the assessment.

Adult