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Estimating the prevalence of mastitis and other organ-specific diseases in the presence of within-animal disease correlation and diagnostic test correlation


, : Estimating the prevalence of mastitis and other organ-specific diseases in the presence of within-animal disease correlation and diagnostic test correlation. Preventive Veterinary Medicine 20(1-2): 113-133

In estimating the prevalence of a disease such as mastitis, which can affect some or all organs in an animal, an epidemiologist may use a diagnostic test of known sensitivity and specificity to test all organs in each animal and designate the animal as disease-positive if at least one organ is test-positive. The epidemiologist is then faced with the problem of choosing a prevalence estimator that accounts both for the sensitivity and specificity of the test and also for the fact that multiple tests have been made on the same animal. This paper examines the effect of disease distribution and test characteristics, including sensitivity, specificity and correlation of test results, on the performance of four animal-level disease prevalence estimators. The crude estimator ( cxa theta-A) is the proportion of animals that test positive in at least one organ; the empirical estimator ( cxa theta-B) is obtained by correcting the crude estimator using the test specificity and the number of times the test was performed on each animal; the corrected estimator ( cxa theta-C) is obtained by correcting the crude estimator for the sensitivity and specificity of the test, but not for the fact that multiple tests were made on each animal; the distribution estimator ( cxa theta-D) is obtained by substituting observed distribution parameters into the beta-binomial density formula. The paper extends the theory from a former paper (Donald, A., 1993, Prevalence estimation using diagnostic tests when there are multiple, correlated disease states in the same animal or farm. Prev. Vet. Med., 15: 125-145) and reports the results of a simulation study that compares the accuracy and precision of the four estimators. The empirical estimator ( cxa theta-B), which exhibits the lowest bias, is recommended as the best estimator in most circumstances. The results of the investigation are applicable not only to mastitis prevalence estimation, but also to the estimation of disease that occurs in small clusters, such as organs on the same animal or animals within small litters.

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Accession: 002373026

DOI: 10.1016/0167-5877(94)90111-2

PDF Full Text: Estimating the prevalence of mastitis and other organ-specific diseases in the presence of within-animal disease correlation and diagnostic test correlation


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Otsuka, F.; Tada, K.; Ogura, T.; Hayakawa, N.; Mimura, Y.; Yamauchi, T.; Inoue, N.; Makino, H.; Kudo, T., 1997: Gestational thyrotoxicosis manifesting as wernicke encephalopathy: a case report. The thyroid gland is physiologically stimulated in normal early pregnancy. This stimulated thyroid function is occasionally termed "gestational transient thyrotoxicosis". The cause of this thyrotoxicosis has been clarified to closely it...

Michal, M., 1994: Mucinous naevocellular naevi. We report 4 cases of a naevocellular naevus variant containing abundant amounts of mucinous matrix. The mucinous matrix was Alcian blue (pH 2.5) and Halle's colloidal iron positive and mucicarmine and PAS negative. When the blocks of tumours...

Archie, J. P-Jr, 1977: Hemodynamic analysis of the portal circulation during temporary portal vein occlusion and after portal systemic shunt surgery. Simple principles of fluid mechanics are used to determine the physical meaning of free and clamped portal vein pressures in patients with portal hypertension undergoing portal-systemic shunt operations. Two frequently used indices of hemodynamic...

Ludwig, R.A.; Johansen, E., 1980: DnaG-suppressing variants of R68.45 with enhanced chromosome donating ability in Rhizobium. Suppressors of the thermosensitive dnaG3 allele have been isolated in strains of Escherichia coli containing the P-type plasmid R68·45. At least one suppressor,R68· 45supdnaG15, maps on the plasmid and completely suppresses t...

Lichtenstein, Stefania, 1933: Reinziichtung von Geflugeltuberkelbakterien aus dem Kot tuberkuloser Huhner. Tubercle bacilli were retrieved from the feces of all 12 chickens subcut, infected with avian tubercle bacilli. In 2 instances bacilli were observed before clinical symptoms appeared. No bacilli were found in 7 controls.

Johnson, R.J., 1999: The potential for Ontario region's health information system to facilitate case management, program planning, and evaluation and to promote enhanced First Nations' control of health services. The Ontario Region of Medical Services Branch, Health Canada, comprises approximately 63,000 First Nations people living on-reserve in four geographical areas: Sioux Lookout, Moose Factory, Thunder Bay, and Southern Ontario. As of April 1996, 35%...

Krarup, T.; Sønderstrup, J.; Kruse-Blinkenberg, H.O.; Schmidt, A., 1979: Surgical treatment of gallstones in the elderly. Ugeskrift for Laeger 141(39): 2657-2659

Hubenov, Zdravko K., 1999: Species composition and zoogeographical characteristic of Tachinidae in the Kresna Gorge. A total of 54 species of the family Tachinidae has been established in the investigated region. They belong to 22 zoogeographical categories, combined into 3 groups. The tachinid fauna of the Kresna Gorge is represented by species of Mediterranean...

Chu, E.; Whitlock, W.L.; Dietrich, R.A., 1990: Pulmonary hyperinfection syndrome with Strongyloides stercoralis. A 65-year-old man with steroid-dependent chronic airflow obstruction presented to the Letterman Army Medical Center, California, USA, with progressive dyspnoea and weight loss. Travel history included a military tour of South East Asia. A chest ro...

Zimen, E.; Boitani, L., 1975: Number and distribution of wolves in Italy. Zeitschrift Saugetierk, 402: 102-112