Auckland District Health Board Research Articles

Modeling the costs of hospital-acquired infections in New Zealand.

To model the economic costs of hospital-acquired infections (HAIs) in New Zealand, by type of HAI. Monte Carlo simulation model. Auckland District Health Board Hospitals (DHBH), the largest publicly funded hospital group in New Zealand supplying secondary and tertiary services. Costs are also estimated for predicted HAIs in admissions to all hospitals in New Zealand. All adults admitted to general medical and general surgical services. Data on the number of cases of HAI were combined with data on the estimated prolongation of hospital stay due to HAI to produce an estimate of the number of bed days attributable to HAI. A cost per bed day value was applied to provide an estimate of the economic cost. Costs were estimated for predicted infections of the urinary tract, surgical wounds, the lower and upper respiratory tracts, the bloodstream, and other sites, and for cases of multiple sites of infection. Sensitivity analyses were undertaken for input variables. The estimated costs of predicted HAIs in medical and surgical admissions to Auckland DHBH were dollar 10.12 (US dollar 4.56) million and dollar 8.64 (US dollar 3.90) million, respectively. They were dollar 51.35 (US dollar 23.16) million and dollar 85.26 (US dollar 38.47) million, respectively, for medical and surgical admissions to all hospitals in New Zealand. The method used produces results that are less precise than those of a specifically designed study using primary data collection, but has been applied at a lower cost The estimated cost of HAIs is substantial but only a proportion of infections can be avoided. Further work is required to identify the most cost-effective strategies for the prevention of HAI.

The prevalence and estimates of the cumulative incidence of hospital-acquired infections among patients admitted to Auckland District Health Board Hospitals in New Zealand.

To report the pooled results of seven prevalence surveys of hospital-acquired infections conducted between November 1996 and November 1999, and to use the data to predict the cumulative incidence of hospital-acquired infections in the same patient group. The summary and modeling of data gathered from the routine surveillance of the point prevalence of hospital-acquired infections. Auckland District Health Board Hospitals (Auckland DHBH), the largest publicly funded hospital group in New Zealand supplying secondary and tertiary services. All inpatients. Point-prevalence surveys were conducted including all patients in Auckland DHBH. Standard definitions of hospital-acquired infection were used. The data from the seven surveys were pooled and used in a modeling exercise to predict the cumulative incidence of hospital-acquired infection. An existing method for the conversion of prevalence to cumulative incidence was applied. Results are presented for all patients and stratified by clinical service and site of hospital-acquired infection. The underlying patterns of hospital-acquired infection by site and service were stable during the seven time periods. The prevalence rate for all patients was 9.5%, with 553 patients identified with one or more hospital-acquired infections from a population of 5,819. The predicted cumulative incidence for all patients was 6.33% (95% confidence interval, 6.20% to 6.46%). The prevalence and the predicted cumulative incidence are similar to rates reported in the international literature. The validity of the predicted cumulative incidence derived here is not known. If it were accurate, then the application of this method would represent a cost-effective alternative to incidence studies.

Vascular dementia: diagnostic criteria for research studies. Report of the NINDS-AIREN International Workshop.

Criteria for the diagnosis of vascular dementia (VaD) that are reliable, valid, and readily applicable in a variety of settings are urgently needed for both clinical and research purposes. To address this need, the Neuroepidemiology Branch of the National Institute of Neurological Disorders and Stroke (NINDS) convened an International Workshop with support from the Association Internationale pour la Recherche et l'Enseignement en Neurosciences (AIREN), resulting in research criteria for the diagnosis of VaD. Compared with other current criteria, these guidelines emphasize (1) the heterogeneity of vascular dementia syndromes and pathologic subtypes including ischemic and hemorrhagic strokes, cerebral hypoxic-ischemic events, and senile leukoencephalopathic lesions; (2) the variability in clinical course, which may be static, remitting, or progressive; (3) specific clinical findings early in the course (eg, gait disorder, incontinence, or mood and personality changes) that support a vascular rather than a degenerative cause; (4) the need to establish a temporal relationship between stroke and dementia onset for a secure diagnosis; (5) the importance of brain imaging to support clinical findings; (6) the value of neuropsychological testing to document impairments in multiple cognitive domains; and (7) a protocol for neuropathologic evaluations and correlative studies of clinical, radiologic, and neuropsychological features. These criteria are intended as a guide for case definition in neuroepidemiologic studies, stratified by levels of certainty (definite, probable, and possible). They await testing and validation and will be revised as more information becomes available.