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J C Jager

Publications and source records attributed to J C Jager.

49 records · Page 3Linked to original sources
PubMed1990

[The epidemiology of AIDS in Amsterdam, 1982-1988].

The results are reported of AIDS monitoring in Amsterdam in the period 1982-1988. Males with homosexual contacts are the principal risk group followed by the fast-growing group of users of intravenous drugs. Transmission of the human immunodeficiency virus to the heterosexual population will occur mostly via sexual contacts with users of drugs. An investigation of the degree of underreporting in Amsterdam revealed 23 unreported patients (5.7% of the cumulative total). The median duration of survival of AIDS patients increased: 1982-1985, 9 months, 1986, 12 months, 1987, 16 months. Two-year survival of patients in the periods 1986 and 1987 was practically the same, however. It is assumed that at the end of 1991, 1124 AIDS patients domiciled in Amsterdam will have been diagnosed.

Acquired Immunodeficiency Syndrome↗
PubMed1990

HIV infection dynamics and intervention experiments in linked risk groups.

A multigroup transmission model is described to study the spread of the human immunodeficiency virus (HIV) in linked risk groups. The model permits simultaneous investigation of the increase in the number of persons infected with HIV in three main risk groups: promiscuous homo/bisexual men (two levels of promiscuity), intravenous drug users (men and women) and promiscuous heterosexual men and women. Three modes of transmission are considered: anal and vaginal intercourse and needle sharing. The high dimensional parameter space is connected with the HIV incidence through a transmission matrix. This matrix summarizes the annual effective contact rates due to the three transmission modes. The model helps to clarify which data are needed to disentangle the relative contribution of the within- and between-group transmission routes. The model can be used to perform theoretical experiments. Given a specification of a baseline, the potential use of the model is illustrated by a simulation describing the effect of blocking the transmission through needle sharing. Reference is made to the HIV/AIDS epidemic in The Netherlands. The results of the study show that the model can play a part in the classification of HIV prevalence patterns in linked risk groups, in the study of the interaction between the main risk groups and in the theoretical evaluation of intervention measures.

Female↗
PubMed1990

Hospital cost for patients with HIV infection in a university hospital in The Netherlands.

Precise data on the utilization of health care facilities by HIV infected patients are generally not available. Nor are there data on the related cost, effectiveness and efficiency of the treatment provided. This is due mainly to the lack of a suitable method for recording demographic, medical and financial data on individual patients in hospitals. For this reason we have been developing a system of data collection, which provides a detailed cost record of each patient. The application of this system for 52 patients with HIV infection treated in a university hospital over a two-year period showed that for a patient with AIDS the mean cost of inpatient and outpatient hospital services was $19,507 per person-year. For patients with HIV infections other than AIDS the mean costs ranged from $1,769 for CDC III patients to $2,064 for CDC II patients (expressed in 1987 US dollars). Continued operation of the registration system will make it possible to analyze the causal background of costs as well as the cost-effectiveness of the treatment.

Acquired Immunodeficiency Syndrome↗
PubMed1989

[Registration and cost estimation of clinical and outpatient activities of patients with HIV infection].

The implications of AIDS for health care are unknown. Precise data about the extent to which patients appeal to hospital health care facilities and resulting costs are not available, mainly due to the absence of suitable methods for the registration of demographic, medical and financial data on individual patients in hospitals. In this paper we present the preliminary results of application of a new system which allows such a detailed collection and analysis of data. By evaluating patients with HIV infections treated in the University Hospital Utrecht between January 1, 1987 and July 1, 1988, the mean yearly costs of in- and outpatient treatment of a patient with AIDS (CDC-IV) were found to be Dfl. 40,267.-; those of treatment of patients with other HIV infections ranged from Dfl. 3,629.-(CDC-III) to Dfl. 5,115.-(CDC-II). Comparison of the mean costs for patients who died in that period with those for patients who did not, reveals that patients dead of AIDS would have cost Dfl. 75,289.-yearly and those with AIDS who were alive at July 1, 1988 Dfl. 27,308.-.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Correcting reported AIDS incidence: a statistical approach.

This study is motivated by the time lag between date of diagnosis of AIDS cases and date of reporting, which results in incomplete data about the epidemic. A maximum likelihood procedure has been developed to adjust the actual numbers of diagnosed AIDS cases for reporting delay. If a parametric function for describing past and future incidence is assumed, its parameters and the adjustment for reporting delay can be estimated simultaneously. Data from the WHO Collaborating Centre on AIDS, Paris, are used. Practical problems related to data collection are dealt with.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Statistical analysis of growth limitations in Paracoccus denitrificans: an experiment with a completely randomized two-way factorial design with replications.

Cultivation of microorganisms under growth limitation is a widely used technique in microbiology. The relevant investigations, though seemingly based on straightforward experiments, have generated conflicting results, e.g., concerning molar growth yields. The purpose of this paper is to show that discrepancies in the literature could be solved if more attention were paid to methodology, especially statistics. New experimental results, concerning growth limitations in Paracoccus denitrificans, will exemplify this. They include the following items. Two limitations, one of them being succinate limitation, were established in the present study. Molar growth yields on succinate were 41 g X mol-1 for succinate limitation (95% confidence limits were 38 and 44) and 32 g X mol-1 for the other limitation (95% confidence limits were 29 and 35). The latter result is compatible with sulphate limitation, but the present experimental design does not really permit this conclusion.

Analysis of Variance↗