Biomedical subjects

J E Cornell

Publications and source records attributed to J E Cornell.

33 records · Page 2Linked to original sources

PubMed1994

The relationship between disease and function and perceived health in very frail elders.

OBJECTIVE: To study associations between disease and observed function and self-perceived health in very frail elders. DESIGN AND SETTING: Cross-sectional survey of nine nursing homes in San Antonio, TX. PARTICIPANTS: 194 elderly long-stay nursing home residents dependent in at least two ADLs and without severe cognitive impairment. MEASURES: Burden of disease (BOD) was chart abstracted using a standardized protocol that assessed types and severities of 59 categorizations of chronic and acute medical conditions. Observed function and self-perceived health status were assessed independently by the Katz Activities of Daily Living scale (ADL) and the Sickness Impact Profile (SIP), respectively. RESULTS: Summary BOD scores had a low, but statistically significant, univariate correlation with ADL scores (r = 0.21, P = 0.003) and no significant correlation with SIP scores (R = -0.008). Multiple linear regression analyses, including the 24 most frequent disease categories, showed that disease explained significant amounts of ADL (r2 = 0.25, P = 0.001) and borderline significant amounts of SIP (r2 = 0.16, P = 0.11). Models including both disease and sociodemographic, cognitive, and affective variables showed disease added significant incremental explantation beyond the other factors to ADL (incremental r2 = 0.14, P = 0.04), but not to SIP (incremental r2 = 0.08, P > 0.10). CONCLUSIONS: Disease, observed function, and self-perceived health status are separate, but interrelated entities, with disease having a stronger relationship to observed function than self-perceived health. Comprehensive assessment of frail elders may need to include all three areas, and studies that focus on one area should take into account the other two as potential important covariates.

Activities of Daily Living↗

PubMed1993

Adverse events related to drugs and drug withdrawal in nursing home residents.

OBJECTIVE: To (1) develop and standardize explicit criteria to link clinical adverse events to drug withdrawal, (2) determine the incidence and severity of Adverse Drug Events (ADEs) and Adverse Drug Withdrawal Events (ADWEs) in a nursing home population, and (3) establish the contribution of demographic, clinical, and functional characteristics to ADEs and ADWEs. DESIGN: Retrospective record review of an admission cohort. SETTING AND SUBJECTS: Consecutive admissions of residents of an academic Veterans Affairs nursing home with available records and lengths of stay > 30 days (n = 175). Subjects were 96% men, aged 70 +/- 12 years, and took 7.0 +/- 3.4 medications. METHODS: We applied standardized algorithms to determine incidence, probability, and severity of ADEs and ADWEs. Multiple regression techniques were used to identify factors associated with frequency and risk of events. RESULTS: Ninety five residents experienced 201 ADEs. Twelve required hospitalization or prolonged hospitalization, and one resident died. Sixty two persons had 94 ADWEs. None were associated with death and one with hospitalization. The four most commonly prescribed drug classes accounted for 72% of ADEs and 80% of ADWEs. Results of multivariate analyses showed common risk factors for both ADEs and ADWEs: number of diagnoses, number of medications, and hospitalization during the nursing home stay. CONCLUSIONS: ADEs and ADWEs were common in nursing home residents in this Veteran's Affairs setting. Explicit criteria developed and applied in this study should be applied prospectively in other settings, both to further define risk of drug discontinuation and to assist in development of specific drug discontinuation guidelines.

Aged↗

PubMed1993

Effects of physical therapy on functional status of nursing home residents.

Nursing home residents typically have decreased functional and physical status and high health care utilization and costs. This randomized trial evaluates whether physical therapy is beneficial for frail debilitated long-stay residents of nursing homes. Subjects are recruited from a cohort of academic and community nursing home residents who have resided in the nursing home for greater than 3 months and are over age 60 and dependent in at least two activities of daily living. Subjects randomized to the intervention group receive one-on-one physical therapy sessions three times weekly for 4 months, while control group subjects receive structured social visits three times weekly to control for potential Hawthorne effects. Physical therapy sessions generally last 30 minutes and consist of functional activity and general conditioning exercises; these exercises are individually tailored to the subject's level of physical and functional disability. Prime outcome variables are physical function assessed by an observer-administered, performance-based instrument and self-perceived health status assessed by the Sickness Impact Profile. Health care utilization and associated costs are calculated for the following areas: the nursing home, hospitalizations, outpatient visits and procedures, medications, and the intervention. A cost-effectiveness ratio dividing incremental health care utilization and physical therapy intervention costs by the observed improvement in physical function is calculated. It is expected that results of this study can be used to help determine whether long-stay nursing home residents should be eligible for physical therapy.

Activities of Daily Living↗

PubMed1993

Falls: an examination of three reporting methods in nursing homes.

OBJECTIVE: To examine the concordance of various fall reporting methods and to use the results to recommend a preferred method of ascertaining fall frequency for residents of nursing homes, both for research and in the collection of federally mandated nursing home data. DESIGN: A cohort study followed for 858 patient months, with a mean individual follow-up of 6.6 months. MEASUREMENTS: Falls were independently ascertained monthly by three methods: review of administrative incident reports, nursing home chart abstraction, and structured interview of subjects. Concordance of events was assessed using measures of simple agreement and Kendall's Tau-b. Simple correlation and multiple regression were used to evaluate the relation of age, sex, gender, depression, mental status, and functional status with degree of concordance between self-reported falls and chart-recorded falls. SETTING: One academic and six community nursing homes in San Antonio, Texas. PARTICIPANTS: 131 long-stay nursing home residents, greater than 60 years of age, dependent in at least two activities of daily living, and mildly cognitively impaired. RESULTS: Falls were ascertained in 74 of the 131 individuals; 53 subjects fell 124 times by incident report, 58 had 140 falls according to chart review, and 66 subjects self-reported 232 falls. Greatest agreement between reporting methods was shown for incident report and chart review, with a Kendall's Tau-b of 0.88; self-report and chart-review agreement was 0.56; and self-report and incident agreement was 0.53. Estimated total fall events were more often (P = 0.001) identified by chart review (92%) than incident report (82%). Although concordance was higher for non-fallers, no significant relationships were observed between concordance and age, sex, race, depression, mental status, and functional status. Also, there was no systematic relationship between length of follow-up and degree of concordance. CONCLUSIONS: Fall frequency varies by ascertainment method, with chart review reflecting a greater number of fall events than the traditionally counted incident reports.

Accidental Falls↗

PubMed1993

Medical treatment preferences of nursing home residents: relationship to function and concordance with surrogate decision-makers.

OBJECTIVE: To describe treatment preferences of nursing home residents, concordance with decisions by self-selected proxies and to establish the relationship of sociodemographic and functional measures to decisions. SETTING AND SUBJECTS: 52 patient-proxy pairs at a Veterans Affairs nursing home. METHODS: Treatment preferences were elicited from residents and proxies regarding cardiopulmonary resuscitation, mechanical ventilation, and intensive care unit care. Hospitalization, intravenous antibiotics, intravenous fluid administration, and tube feeding were presented in three separate health scenarios. Concordance was determined for the entire interview and separately for each scenario. Treatment-seeking intensity and decision-making consistency were scored and used to explore associations with sociodemographic variables and function. RESULTS: Subjects were predominantly male (97%) and non-Hispanic white (74%); average age was 70 +/- 12 years, with 4 +/- 2.9 diagnoses. Residents accepted 70% of all treatments. The proportion of subjects accepting interventions declined parallel to health status in each scenario. Only 7/52 (13%) subjects made inconsistent decisions. Resident treatment acceptance was inversely associated with GDS scores but not associated with any other sociodemographic or functional measure. Concordance with proxies was no greater than chance. Proxies' decisions were not systematically biased against resident preferences or influenced by patient characteristics. CONCLUSIONS: Veterans desired most treatments, but adjusted preferences according to health status and were not inconsistent. Depressive symptoms should be addressed prior to advance directive selection. The patient remains the best source of information, but proxies' decisions exhibit no bias and are not affected by patient status.

Activities of Daily Living↗

PubMed1989

Respiratory health of brickworkers in Cape Town, South Africa. Symptoms, signs and pulmonary function abnormalities.

The respiratory health of 268 brickworkers in five brickworks was investigated by means of a questionnaire, a physical examination, and pulmonary function testing. The prevalence of respiratory symptoms ranged from 7% for chronic bronchitis to 52% for morning cough to 27% for both chest tightness and wheeze and 9% for dyspnea at effort. A stepwise logistic regression analysis showed the symptoms to be significantly predicted by combinations of smoking and exposure to dust, while a multiple linear regression showed an effect of dust exposure on forced vital capacity and forced expiratory volume in 1 s but no smoking effect. Smoking generally had less of an effect than dust and predicted early/mild symptoms only.

Adult↗

PubMed1987

Compensation for occupational diseases in the RSA.

Compensation legislation for occupational disease in the RSA is at present complex and non-uniform, and the administrative bodies that process compensation claims are understaffed. In this setting occupational disease, particularly in migrant workers who are often ignorant of their rights under the law, frequently goes uncompensated. General practitioners and medical officers need to be aware of the basic provisions in the law, and how to submit claims in the best interests of their patients. Some case studies are included to illustrate problematic areas. The responsibilities of doctors in the diagnosis and compensation of occupational diseases are addressed.

Adult↗

PubMed1987

A respiratory epidemiological survey of workers in a small South African foundry.

A cross-sectional study to assess prevalence of respiratory abnormality was conducted among 107 South African foundry workers. The prevalence of pneumoconiosis was 10.3% overall, increasing to 38% for workers with more than 15 years of service. Dyspnea was present in 38% of workers, chronic simple bronchitis in 15.9%, and asthmatic symptoms in 27%. Pneumoconiosis was not associated with higher prevalence rates of other respiratory abnormalities. The high overall prevalence of respiratory symptoms might be explained by exposure to environmental pollutants other than dust.

Adult↗

PubMed1987

Interaction between renal prostaglandins and angiotensin II in controlling glomerular filtration in the dog.

Although previous studies suggest that the renal vasoconstrictor effects of angiotensin II (ANG II) are normally confined to the efferent arterioles, the mechanisms that prevent ANG II from constricting preglomerular vessels are still unclear. In the present study, the role of prostaglandins (PG) in protecting preglomerular vessels from ANG II constriction was examined in dogs with normal or non-filtering kidneys in which ANG II formation was blocked with captopril and renal artery pressure was servo-controlled at 75-80 mmHg. Before PG blockade (n = 6), ANG II infusion (20 ng min-1 kg-1) decreased renal blood flow (RBF) by 54 +/- 4%, but did not change glomerular filtration rate (GFR) significantly. After PG blockade (n = 6), ANG II infusion decreased GFR by 37 +/- 7% and RBF by 56 +/- 6%, while increasing calculated preglomerular resistance much more than before PG blockade. In another group of dogs, secondary changes in renal resistances, due to tubuloglomerular feedback, were prevented by occluding the ureter during mannitol diuresis until glomerular filtration ceased. After inhibition of tubuloglomerular feedback in non-filtering kidneys (n = 7), ANG II decreased RBF by 40 +/- 3% and increased glomerular hydrostatic pressure, estimated from stop-flow ureteral pressure and plasma colloid osmotic pressure, by 8.7 +/- 1.7 mmHg. Postglomerular resistance increased by 91 +/- 12% while preglomerular resistance was unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗

PubMed1985

A respiratory epidemiological study of stevedores intermittently exposed to asbestos in a South African port.

The prevalence of asbestosis in stevedores intermittently transporting crocidolite asbestos in a South African port was found to be 30% in a cross-sectional survey. Diagnostic criteria are discussed in terms of the low index of suspicion for industrial diseases, the high probability of missing slight radiological changes, and the attribution of radiological lesions to other diseases, particularly tuberculosis, in a high prevalence area. Results are compared with other studies. Asbestosis was not associated with tuberculosis. Smoking was not significantly associated with asbestosis, other respiratory signs and symptoms, or radiological abnormality.

Adult↗

PubMed1985

Maintenance of renal autoregulation during infusion of aminophylline or adenosine.

Adenosine has been postulated to link control of glomerular filtration rate (GFR) and renal blood flow (RBF) with changes in renal metabolism. In the present study, we examined the role of adenosine in renal autoregulation by comparing the responses of normal anesthetized dogs to step decreases in renal artery pressure (RAP) to the response obtained after receptor blockade of adenosine with aminophylline or by flooding the kidney with exogenous adenosine. In six dogs at normal RAP, intrarenal infusion of aminophylline (10 mumol/min) did not alter renal hemodynamics. GFR and RBF were well autoregulated (greater than 90% of control) at RAP values equal to or greater than 85 mmHg before and after aminophylline. At RAP equal to 75 mmHg, GFR and RBF decreased by 27 +/- 10 and 20 +/- 8%, respectively, before aminophylline and by 25 +/- 7 and 13 +/- 6% after aminophylline. In a different group of six dogs, intrarenal infusion of adenosine (6 mumol/min) significantly increased RBF (32 +/- 9%) and decreased GFR (38 +/- 10%) at normal RAP. However, GFR and RBF were both well autoregulated (greater than 90% of control) at RAP values equal to or greater than 85 mmHg before and after adenosine. At RAP equal to 75 mmHg, GFR and RBF decreased by 10 +/- 5 and 7 +/- 3%, respectively, before adenosine and by 12 +/- 6 and 17 +/- 5% after adenosine. Neither aminophylline nor adenosine attenuated the elevations in plasma renin activity associated with reductions in RAP. These data fail to provide evidence that adenosine is an important factor in autoregulation of GFR and RBF during acute reductions in RAP within the autoregulatory range.

Adenosine↗

PubMed1985

Mechanisms of angiotensin II natriuresis and antinatriuresis.

The aim of this study was to determine the role of changes in renal arterial pressure (RAP), renal hemodynamics, and tubular reabsorption in mediating the natriuretic and antinatriuretic actions of angiotensin II (ANG II). In seven anesthetized dogs, endogenous ANG II formation was blocked with captopril, and ANG II was infused intravenously at rates of 5-1,215 ng X kg-1 X min-1 while RAP was either servo-controlled at the preinfusion level or permitted to increase. When RAP was servo-controlled, ANG II infusion at all rates from 5-1,215 ng X kg-1 X min-1 decreased urinary sodium excretion (UNaV) and fractional sodium excretion (FENa) while increasing fractional reabsorption of lithium (FRLi) (an index of proximal tubular fractional sodium reabsorption) and causing no change in calculated distal tubule fractional sodium reabsorption (FRDNa). When RAP was permitted to increase, ANG II infusion rates up to 45 ng X kg-1. min-1 also decreased UNaV and FENa while increasing FRLi and causing no change in FRDNa. However, at 135 ng X kg-1 X min-1 and above, UNaV and FENa increased while FRLi and FRDNa decreased when RAP was allowed to rise, even though renal blood flow and filtration fraction were not substantially different from the values observed when RAP was servo-controlled. Filtered sodium load was slightly higher when RAP was permitted to increase during ANG II infusion compared with when RAP was servo-controlled, although the differences were not statistically significant. Thus, even very large doses of ANG II cause antinatriuresis when RAP is prevented from increasing.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗

PubMed1985

Protection of preglomerular vessels from angiotensin II vasoconstriction by renal prostaglandins.

Previous studies suggest that the renal vasoconstrictor effect of angiotensin II (ANG II) is confined primarily to efferent arterioles, with little direct action on preglomerular vessels. The present study examined the role of prostaglandins (PG) in protecting preglomerular vessels from ANG II constriction. In dogs in which ANG II formation was blocked with captopril and renal artery pressure was servo-controlled, i.v. ANG II infusion (20 ng/kg per min) decreased renal blood flow (RBF) by about 50% while causing no significant change in glomerular filtration rate (GFR) and increasing filtration fraction (FF). After PG blockade, ANG II infusion decreased GFR by more than 30% and RBF by more than 50%, while causing much greater increases in calculated preglomerular resistance (RA) than in dogs without PG blockade. To prevent secondary changes in renal resistances via tubuloglomerular feedback (TGF), glomerular filtration was stopped by occluding the ureter during mannitol diuresis. After inhibition of TGF, ANG II decreased RBF markedly and increased glomerular hydrostatic pressure by 8-10 mmHg due to large increases in postglomerular resistance (RE) with no change in RA. After PG blockade and inhibition of TGF, ANG II decreased RBF by about the same amount as in control dogs but did not change glomerular hydrostatic pressure due to marked increases in both RA and RE. These data suggest that PGs selectively protect preglomerular vessels from ANG II constriction but do not interfere with the effect of ANG II on efferent arterioles.

Angiotensin II↗

PubMed1982

Prevalence of hypertension in semi-skilled manual workers.

This study demonstrates a high prevalence of hypertension (43,9%) in a population of unskilled manual workers. No differences were detected in the prevalence rates for two ethnic groups. The importance of age standardization for comparison of data with other studies of an age-linked phenomenon such as hypertension is stressed. Blood pressure was higher in workers who had worked their daily shift than in those who had not worked a shift. These findings might be explained by means of an hypothesis linking stress at work with hypertension. The literature relevant to this hypothesis is outlined.

Adult↗

PubMed1979

An analysis of distance variables that affect aftercare attendance.

Recent reserach has examined variables related to attendance of aftercare services because of the correlation between aftercare and posthospitalization treatment success. The present study, which examined aftercare attendance for 40 randomyl selected subjects following discharge from an inpatient alcohol treatment program, extends the list of variables found to influence attendance. A multiple-regression analysis of subject demographic variables and variables of a more programmatic nature found that distance variables (e.g., number of miles to an aftercare agency) significantly influenced aftercare attendance. The results are discussed with respect to aftercare program decisions.

Adult↗