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H A Kahn

Publications and source records attributed to H A Kahn.

14 recordsLinked to original sources
PubMed1987

A step towards using urinary nitrogen as a tool for validating 24-hour dietary recall interviews.

In an active population, can urinary nitrogen output provide a satisfactory basis for estimating protein intake without preliminary screening to rule out metabolic disease? A successful demonstration would justify comparing average protein intake for active groups derived from 24-hour recall interviews with that obtained from 24-hour urine specimens. This could then be a practical test of the hypothesis that 24-hour recall data provide valid estimates for groups. Volunteers (45) from a university population limited their diet for four days to a commercially prepared liquid diet and provided a 24-hour urine specimen beginning on the morning of the fourth day. For men, average daily intake of protein was 112.8 grams and the estimated intake based on urinary nitrogen was 114.5. Corresponding data for women were 84.6 and 83.9. Screening for metabolic disease seems unnecessary but persons restricting their intake to less than their caloric needs will have their protein intake overestimated on the basis of urinary nitrogen measurement.

Adult↗
PubMed1985

Multiple logistic function versus Mantel-Haenszel procedure in the analysis of risk factors for prevalence of hepatitis A antibodies.

Multiple logistic function and Mantel-Haenszel procedure are compared in their ability to control confounding in a large set of data. In this specific application substantial equivalence is found between the two techniques. When both techniques are applicable and data are not sparse, the authors prefer stratification, which is simpler and free of assumptions.

Hepatitis A↗
PubMed1979

Quality assurance of clinical data: diagnostic standardization.

Diagnostic standardization requires substantial effort, including detailed specification of procedures in a written protocol and training of examiners in such procedures. Success is neither automatic nor assured. It is essential to monitor performance through replicate examinations and/or computation of examiner variance. When examiner variance exceeds permissible limits, consideration should be given to discarding the data.

Clinical Trials as Topic↗
PubMed1977

The Framingham Eye Study. I. Outline and major prevalence findings.

During the period 1973--1975, 2675 out of 3977 still-living members of the Framingham, Massachusetts, study population, who have been under investigation for coronary disease risk factors since 1948 and who were in 1973--1975 aged 52 to 85, were given an eye examination stressing cataract, diabetic retinopathy, macular degeneration and glaucoma. Of 2940 subjects who still lived in the local Framingham area, 2477 were examined. Local population prevalence for one or both eyes positive was: 15.5% for senile cataract, 3.1% for diabetic retinopathy, 8.8% for senile macular degeneration and 3.3% for open-angle glaucoma. The proportion of adults with poor "best" visual acuity may be much less than has been estimated by the National Health Survey and the proportion with open-angle glaucoma much more than currently suspected on the basis of foreign studies.

Age Factors↗
PubMed1977

The Framingham Eye Study. II. Association of ophthalmic pathology with single variables previously measured in the Framingham Heart Study.

Using the age-sex-specific data collected in the Framingham Heart Study 1948--1964 together with ophthalmic diagnoses made in the Framingham Eye Study in 1973--1975, the following variables were found to be associated with senile cataract: education, casual blood sugar, systemic blood pressure, height, vital capacity, serum phospholipid and hand strength; with senile macular degeneration: systemic blood pressure, height, vital capacity, left ventricular hypertrophy, hand strength and history of lung infection; with diabetic retinopathy: casual blood sugar, urine sugar and other specific elements of diabetes; with ocular hypertension: systemic blood pressure, height, casual blood sugar and pulse rate. No variables were identified as associated with open-angle glaucoma. The paper stresses the need for corroboration of these findings, which may be a mix of real and chance associations, and the need for additional analyses before any of these associations are considered evidence of factors related to risk of ophthalmic disease.

Aged↗
PubMed1976

The association of femal hormones with blindness from diabetic retinopathy.

The rates of blindness from diabetic retinopathy with or without other causes for persons in the Model Reporting Area (14 states) were determined in five-year intervals by sex. Diabetic males younger than 45 years of age had a higher rate of diabetic blindness than females under 45 years of age. However, for ages 45 and older, the risks of blindness among diabetics were approximately equal for men and women. These data were consistent with the hypothesis that the presence of female hormones improves the prognosis in diabetic retinopathy.

Adult↗
PubMed1976

Senile cataract extraction and diabetes.

A study of hospital discharge diagnoses from both national data and data from a local medical centre indicates that diabetes substantially increases the probability of cataract extraction at age 40-49, about doubles or triples the probability for age 50-69, and has little effect on risk at age 70 and over. Strengths and weaknesses of the data are discussed. Other reports, generally estimating a much stronger association between diabetes and probability of cataract extraction, at least at age 50 and above, are critically evaluated.

Adult↗
PubMed1975

Blindness from glaucoma.

We observed an overall ratio of 8:1 for nonwhite to white primary glaucoma blindness. Our fragmentary evidence suggested that the ratio of underlying disease, that is, nonblinding glaucoma or intraocular pressure differentials, may be closer to 2:1 than 8:1 as between nonwhites and whites. The remaining four fold differential can be explained by a combination of the following: more complete reporting for nonwhites, reporting for medical care later in the disease than whites, and poorer response to treatment for nonwhites compared to whites. The trend of new blindness from glaucoma for recent years was stationary in the United States, England, and Wales.

Adolescent↗
PubMed1975

Prevalence of diabetic retinopathy. Age, sex, and duration of diabetes.

From a list of all patients seen at the Joslin Clinic in a recent 6-month period, a random sample of 965 was selected for record review by a clinic assistant. A house physician specializing in diabetes then verified and adjusted the assistant's work as necessary. The data were analyzed both by simple cross-classification and by fitting a multiple logistic risk function. As often reported previously, we found a strong positive association between retinopathy and duration of diabetes. One of our findings which has not been so clearly reported in earlier papers is that the positive association between retinopathy and age is limited to the group with diabetes of less than 10 years' duration. We also found sex differences in retinopathy prevalence which were not large enough to rule out attributing them to chance.

Adult↗