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Biomedical subjects

S A Grover

Publications and source records attributed to S A Grover.

At least 55 records · Page 3Linked to original sources
PubMed1994

Risk-benefit assessment of drug treatment to prevent coronary heart disease. Estimating the benefits of risk factor modification.

Risk factor modification to prevent the development of coronary heart disease (CHD) is a rapidly growing concern of physicians interested in disease prevention. Drug treatments to reduce hypertension and hyperlipidaemia are 2 important interventions for CHD primary prevention. The benefits of these interventions have been demonstrated in short term clinical trials by reducing the incidence of stroke and coronary events. While the short term benefits may appear modest, the long term changes in life expectancy and disease morbidity may be substantial for carefully targeted groups of patients. Computer models are therefore increasingly being used to estimate the long term benefits of risk factor modification among selected patients. A review of published CHD models demonstrates that predictions among the different models are usually consistent. Moreover, the results of randomised clinical trials can be accurately forecasted using the CHD Primary Prevention Model.

Adult↗
PubMed1993

Modifying serum lipids to prevent coronary heart disease: do we have a consensus?

Despite the importance of hyperlipidemia as an independent coronary risk factor and the positive results of recent lipid intervention trials to prevent coronary disease, there remain many unanswered questions regarding the benefits and risks of treating hyperlipidemia. Critical review of epidemiologic studies and clinical trials suggest that the benefits of cholesterol reduction may vary depending on the patient's age, sex, and the presence of other coronary risk factors. Furthermore, one must recognize that there is a small but consistent increase in noncoronary deaths among patients receiving cholesterol-lowering medications that remains unexplained but requires further evaluation. These data underscore the importance of weighing both the risks and benefits of modifying serum lipids. Accordingly, careful evaluation of the underlying risk of developing coronary disease and the potential long-term benefits of intervention are necessary to identify appropriate high-risk patients for treatment among whom the predicted benefits will outweigh the risks.

Cholesterol, HDL↗
PubMed1992

Economic impact of HIV infection and coronary heart disease in immigrants to Canada.

OBJECTIVE: To compare the direct health care costs of illnesses associated with the human immunodeficiency virus (HIV) and of coronary heart disease (CHD) in immigrants to Canada. DESIGN: Comparative cost analysis. PARTICIPANTS: All people who immigrated to Canada in 1988. The numbers with HIV infection and CHD were estimated from country-specific HIV seroprevalence data and national CHD mortality statistics and data from the Framingham study. Health care costs, projected over the 10 years after immigration, were calculated on the basis of data from the Hospital Medical Records Institute and provincial fee schedules. RESULTS: Of the 161,929 immigrants in 1988, 484 were estimated to be HIV positive. The total cost of treatment of HIV-related illnesses from 1989 to 1998 (discounted at 3%) would be $18.5 million: $17.1 million would be spent on the outpatient and inpatient care of the HIV-positive immigrants, $1.0 million on care of the subsequently infected sexual partners and $0.4 million on care of the HIV-positive children born to seropositive immigrant women. In comparison, CHD would develop in 2558 immigrants during the same 10-year period. The total CHD costs would be $21.6 million: $8.4 million would be spent on treating myocardial infarction, $3.2 million on coronary artery bypass grafting, $1.6 million on pacemaker insertion and $8.4 million on treating other CHD events. CONCLUSIONS: The economic impact of HIV infection in immigrants to Canada is similar to that of CHD. This comparison identifies an important shortcoming in current immigration policy: economic considerations can be arbitrarily applied to certain diseases, thereby discriminating against specific groups of immigrants.

Adult↗
PubMed1992

The benefits of treating hyperlipidemia to prevent coronary heart disease. Estimating changes in life expectancy and morbidity.

OBJECTIVE: To evaluate the lifetime benefits of reducing total serum cholesterol levels to prevent coronary heart disease (CHD). DESIGN: We developed a CHD primary prevention computer model to estimate the benefits associated with lifelong risk factor modification. We validated the model by comparing the computer estimates with the observed results of three primary CHD prevention trials. PATIENTS: Men and women age 35 to 65 years who are free of CHD, with total serum cholesterol levels ranging from 5.2 to 7.8 mmol/L (200 to 300 mg/dL), with or without additional CHD risk factors. INTERVENTIONS: Serum cholesterol reduction through dietary modification or diet and medications. MAIN OUTCOME MEASURES: Changes in life expectancy and the delay of symptomatic CHD. RESULTS: The computer forecasts for CHD end points closely matched the observed results of the Lipid Research Clinics Trial, the Helsinki Heart Study, and MRFIT. We then applied the computer model to low-risk and high-risk men and women with total serum cholesterol levels between 5.2 and 7.8 mmol/L (200 and 300 mg/dL) and estimated that, after reducing serum cholesterol levels 5% to 33%, the average life expectancy would increase by 0.03 to 3.16 years. We also forecast that the average onset of symptomatic CHD would be delayed among these patient groups by 0.06 to 4.98 years. CONCLUSION: We conclude that this computer model accurately estimates the results of clinical trials and can be used to forecast the changes in life expectancy and morbidity (the development of CHD) associated with specific CHD risk reduction interventions. The wide variation surrounding these estimates underscores the need to better define which groups of individuals will gain the most from cholesterol reduction.

Adult↗
PubMed1992

The clinical utility of serum lactate dehydrogenase in diagnosing pneumocystis carinii pneumonia among hospitalized AIDS patients.

It has been previously demonstrated that serum lactate dehydrogenase is elevated among HIV patients with pneumocystis carinii pneumonia (PCP). To evaluate the clinical utility of this test we analyzed the admission LDH levels of patients hospitalized for the first time due to the secondary complications of AIDS. Among 76 patients without a prior history of PCP, 41 (54%) had PCP diagnosed during their hospitalization while 35 (46%) did not have PCP. Serum LDH was significantly higher among PCP patients than in patients without PCP (mean = 423 IU/L vs 234 IU/L). Receiver operating characteristic curve analysis demonstrated that at an optimal cutoff point of LDH greater than or equal to 240 IU/L, the test sensitivity and specificity were 0.78 and 0.74 respectively among all hospitalized patients. However, when only patients with dyspnea were considered, the optimal test sensitivity and specificity improved to 0.94 and 0.78 at a cutoff point of LDH greater than or equal to 220 IU/L. Comparing the areas under fitted ROC curves, serum LDH was a significantly better discriminator among patients with dyspnea than among those who were not short of breath. We conclude that while serum LDH is strongly associated with the presence of PCP among AIDS patients, it is a poor screening test for PCP when applied to all hospitalized AIDS patients with and without respiratory complaints. Serum LDH is no substitute for appropriate microbiological studies. However, with further evaluation, it may prove to be a useful test in guiding the clinical management of dyspneic patients in whom sputum or bronchial examinations are negative or not immediately available.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Screening for hypercholesterolemia among Canadians: how much will it cost?

OBJECTIVE: To determine the cost of screening all Canadians aged 30 years or more without coronary heart disease (CHD) for hypercholesterolemia. DATA SOURCES: The expected results of initial screening of the serum cholesterol level were estimated on the basis of 1986 Canadian census data and the 1978 Canada Health Survey. The results of repeat testing were estimated on the basis of data from the Lipid Research Clinics Prevalence Study. Lipid profile results were extrapolated from tests at the Montreal General Hospital's clinical chemistry laboratory. Laboratory costs and primary care practitioner costs were provided by the Canadian Society of Clinical Chemists and provincial fee schedules respectively. MAIN RESULTS: Among 12,479,356 Canadians free of CHD 48.7% would be identified as being at high risk, 4.8% would be identified as being at moderate risk, and 46.6% would be reassured that their lipid risk for CHD was low. The total cost of implementing the program in the first year would be $432 million to $561 million ($325 million for laboratory tests and $107 million to $236 million for visits to primary care practitioners). CONCLUSION: The substantial cost of implementing a nationwide screening program must be weighed against the expected benefits to ensure that the final result is both practical and economically feasible.

Adult↗
PubMed1991

The bedside assessment of splenic enlargement.

STUDY OBJECTIVE: To evaluate the clinical assessment of splenic enlargement using specific bedside maneuvers including Traube's space percussion, the splenic percussion sign, Middleton's maneuver, supine palpation, and right lateral decubitus palpation. DESIGN: Quasi-experimental prospective study of cases and controls selected according to the results of abdominal ultrasonographic examinations. SETTING: Selected inpatients of a tertiary care hospital. MAIN RESULTS: Comparing the areas under the receiver operating characteristic curves for each bedside maneuver demonstrated that Traube's space percussion and palpation were significant discriminators (p less than 0.001) of splenic enlargement with respective areas of 0.70 +/- 0.04 and 0.76 +/- 0.04. No one palpation maneuver was superior to another, and right lateral decubitus palpation was not useful when performed after supine palpation. The splenic percussion sign (sensitivity 79%, specificity 46%) was no better than Traube's space percussion (sensitivity 62% and specificity 72%) in assessing splenic enlargement. The palpation maneuvers appeared more sensitive and more specific than Traube's space percussion. Palpation was a significant clinical discriminator when performed on patients who exhibited percussion dullness of Traube's space (area = 0.87 +/- 0.04, p less than 0.0001) but was of little value among those without percussion dullness (area = 0.55 +/- 0.08). Also, palpation was significantly more accurate when performed on lean patients versus obese patients (areas = 0.83 +/- 0.04 versus 0.65 +/- 0.08, p less than 0.05). When a positive bedside examination was defined as positive palpation and positive percussion (concordant-positive), the combined test sensitivity and specificity were 46% and 97% respectively. CONCLUSIONS: The optimal clinical assessment of splenic enlargement includes the percussion of Traube's space. If Traube's space is dull, palpation of the spleen is warranted. This assessment is most accurate in lean patients.

Adult↗
PubMed1989

Delayed diagnosis of gynecologic tumors in elderly women: relation to national medical practice patterns.

PURPOSE: To evaluate the hypothesis that less aggressive cancer screening practices might result in later diagnosis of cancer in the elderly, we analyzed the stage of diagnosis of tumors by age in the Connecticut Tumor Registry. PATIENTS AND METHODS: Using Registry data from 1960 to 1975 and 1976 to 1983, we compared the proportion of tumors that were diagnosed at a localized stage among white women of various age groups. Thirteen specific tumor sites were analyzed, accounting for 55,688 tumors between 1960 and 1975 and 38,715 tumors between 1976 and 1983. RESULTS: Only gynecologic cancers demonstrated a significant inverse relationship between the relative proportion of tumors that were diagnosed at a localized stage and advancing patient age during both time periods. Specifically, when the youngest women (aged 25 to 34) were compared with the oldest women (aged 85 and over), between 1960 and 1975, the relative proportion of localized cervical, uterine, and ovarian cancer dropped from 98 percent to 59 percent, 92 percent to 77 percent, and 59 percent to 27 percent, respectively. Similar declines were also seen between the intermediate-age groups, and data from 1976 to 1983 demonstrated identical age-related trends. CONCLUSION: Our study reveals that the probability of diagnosing cancer of the cervix, uterus and ovaries at a localized and potentially curable stage decreases with advancing age. Published national health practice patterns demonstrated a similar age-related decline in gynecologic examinations and Pap smears even after adjustment for the exclusion of women who would have undergone previous hysterectomy. This decreasing use of gynecologic examinations may in part explain the age-related decline in localized gynecologic cancers.

Adult↗
PubMed1989

Splenic enlargement and Traube's space: how useful is percussion?

PURPOSE: The utility of Traube's space percussion in the bedside assessment of splenic enlargement was evaluated. The influence of meals and obesity on this sign were also assessed, because both are believed to interfere with the results of abdominal percussion. PATIENTS AND METHODS: The inpatient population of a tertiary care hospital was studied where cases and controls were selected according to the results of abdominal ultrasonographic examinations. RESULTS: Traube's space percussion exhibited a sensitivity of 0.62 (95% confidence interval [CI], 0.51 to 0.71) and a specificity of 0.72 (95% CI, 0.65 to 0.80) when classifying tympanitic examinations as negative. False-positive examinations were reduced by assessing patients more than two hours after mealtime. Obese patients were a source of false-negative examinations. CONCLUSION: Traube's space percussion compares favorably with other commonly used clinical maneuvers and diagnostic tests. When performed alone in a selected patient population, it adds useful clinical information but is not sufficiently sensitive or specific to obviate the need for further diagnostic testing.

Adult↗
PubMed1988

The impact of Medicare on early cancer detection in the elderly.

In an analysis of 23 sex-specific tumors in the Connecticut Tumor Registry, only seven tumors showed more than a 20 per cent increase in the ratio of localized tumors detected post-Medicare (1967-75) versus ante-Medicare (1960-65) in the 65-75 year age group compared to the 60-64 year age group. Of these seven, the information was more convincing for lung cancer in males. Overall, however, Medicare had little if any impact on early tumor diagnosis in the elderly.

Age Factors↗
PubMedDate not supplied

The characteristics and hospital course of patients admitted for presumed acute pyelonephritis.

To study the characteristics and hospital courses of patients hospitalized for presumed acute pyelonephritis, the authors analyzed 185 cases. Judged by explicit clinical and laboratory criteria, 54% of the patients definitely had pyelonephritis, 22% probably had pyelonephritis, 9% possibly had pyelonephritis, and 16% did not have pyelonephritis. In pretreatment urine cultures, 79% of patients had a single pathogen and 77% had colony counts of 100,000 or more organisms per ml. Non-Escherichia coli infections and positive blood cultures were the only two independent predictors of the concomitant renal stones or genitourinary tract abnormalities that were found in 29% of patients with pyelonephritis. About 15% of all patients continued to have temperatures greater than or equal to 101 degrees F 48 hours after the initiation of antibiotic therapy, but persistent fever did not correlate with a history of prior urinary tract infection, the presence of resistant pathogens, renal stones, or genitourinary tract abnormalities. The authors conclude that many of these patients did not have pyelonephritis, and that certain characteristics correlate with the presence of underlying anatomic abnormalities.

Acute Disease↗
PubMedDate not supplied

Seizure vs. syncope: measuring serum creatine kinase in the emergency department.

OBJECTIVE: To determine the utility of serum creatine kinase measurement for diagnosing generalized tonic-clonic seizures in patients presenting to an emergency department with transient loss of consciousness. DESIGN: Prospective evaluation of a diagnostic parameter. Retrospective data collection with blinded assignment to diagnostic groups. SETTING: University teaching hospital. PATIENTS: Sequential sample of 205 patients with transient loss of consciousness. The study group consisted of 96 patients who had creatine kinase measurements in the emergency department. MEASUREMENTS AND MAIN RESULTS: An investigator blinded to the results of creatine kinase measurements retrospectively classified events into seizure and nonseizure groups on the basis of clinical presentation, prior history, and follow-up investigations. Mean (+/- SE) creatine kinase level was significantly higher in the seizure group (231.1 +/- 34.8 U/L vs. 70.5 +/- 5.6 U/L, p less than 0.001). Elevated creatine kinase had a test specificity of 0.98 (95% CI 0.90-1.00) and a sensitivity of 0.43 (95% CI 0.28-0.59). The discriminating power of creatine kinase elevation was directly related to the time interval between the event and testing (p less than 0.0001). Among samples taken more than three hours after the event, test sensitivity was 0.80 (0.52-1.00) and specificity was 0.94 (0.71-1.00). CONCLUSION: Creatine kinase may be a useful test for evaluating patients with transient loss of consciousness. The test is highly specific for diagnosing generalized seizures in the emergency department. Test sensitivity improves by sampling serum at least three hours after the event.

Creatine Kinase↗
PubMedDate not supplied

The cost-effectiveness of exercise training for the primary and secondary prevention of cardiovascular disease.

BACKGROUND: Although exercise training improves cardiovascular disease (CVD) risk factors, few studies have evaluated its potential long-term cost-effectiveness. METHODS: Using the Cardiovascular Disease Life Expectancy Model, a validated disease simulation model, we calculated the life expectancy of average 35- to 74-year-old Canadians found in the 1992 Canadian Heart Health Survey. The impacts of exercise training on cardiovascular risk factors were estimated as a 4% decrease in low-density lipoprotein (LDL) cholesterol, a 5% increase in high-density lipoprotein (HDL) cholesterol, and a 6 mm Hg decrease in both systolic and diastolic blood pressure. Exercise adherence was estimated at 50% for the first year and 30% for all additional years. Costs for a supervised exercise program determined from Canadian sources and converted to US dollars were estimated at $605 for the first year (medical evaluation, stress test, exercise prescription, and program costs) and $367 for all additional years (program costs). For an unsupervised program, the costs were estimated at $311 for the first year and $73 for all additional years. RESULTS: The cost-effectiveness (CE) of an unsupervised exercise program (1996 U.S. dollars) was less than $12,000 per year of life saved (YOLS) for all individuals. The CE of a supervised exercise program was less than $15,000/YOLS for men with CVD, and between $12,000 and $43,000 for women with CVD and men without CVD. CONCLUSIONS: Given the relatively few risks, substantial long-term benefits, and modest costs, an unsupervised exercise training program represents good value for all. A more expensive supervised exercise program is also cost-effective for most individuals with CVD.

Adult↗
PubMedDate not supplied

Conventional and chained standard gambles in the assessment of coronary heart disease prevention and treatment. Canadian Collaborative Cardiac Assessment Group.

The authors compared the abilities of descriptive and valuational health-related quality-of-life measures to discriminate healthy participants (n=39) from those on diets for dyslipidemia (n=35) and angina patients (n=30). On the rating scale, the time tradeoff, and the General Health Perception subscale of the SF-36 Health Survey, the participants with dyslipidemia or angina reported lower mean scores than the healthy participants. No differences were detected between these groups on conventional or chained standard gamble (SG) scales. The distribution of the conventional and the chained SG scores was very skewed, with the vast majority of scores being equal or very close to the maximum score. It is concluded that in this study the discriminant ability of the chained SG was comparable to that of the conventional SG and inferior to descriptive and non-risky valuational scaling techniques. This may be explained by the distortion of probabilities, by a misunderstanding of the SG chained assessment, and by a strong certainty effect.

Adult↗