PubMed Health⌕ Search

Biomedical subjects

Michael Baker

Publications and source records attributed to Michael Baker.

29 records · Page 2Linked to original sources

Economic cost of community-acquired pneumonia in New Zealand adults.

AIMS: The aim of this study was to evaluate the economic cost of community-acquired pneumonia (CAP) in New Zealand adults. Although this is an important illness, there is little published information on the national costs of treatment. Without such information, new treatment options cannot be evaluated in economic terms. METHODS: Costs were estimated from a societal perspective for the adult population (aged 15 years and over) using New Zealand age-specific hospital admission rates (average of 2000-2002), population data (2003), and unit costs (2003) in combination with international data on the proportion of pneumonia cases hospitalised. Univariate and multivariate sensitivity analyses were used to determine the major cost drivers and evaluate uncertainty in the estimates. RESULTS: It was estimated that in 2003 there were 26,826 episodes of pneumonia in adults; a rate of 859 per 100,000 people. The annual cost was estimated to be 63 million dollars, (direct medical costs of 29 million dollars; direct non-medical costs of 1 million dollars; lost productivity of 33 million dollars). CONCLUSIONS: The major generators of costs for community-acquired pneumonia are the number of hospitalisations (particularly for the group aged 65 years and over) and loss of productivity. Intensified prevention and effective community treatment programmes focussing on the 65 years and older age groups should be investigated (as they have the greatest potential to reduce healthcare costs).

Adolescent↗

Lack of association between long-term illness and infectious intestinal disease in New Zealand.

AIMS: To investigate whether the increase in notified cases of infectious intestinal disease in New Zealand from 1988 to 2001 has resulted in a concurrent increase in associated secondary illness cases. METHODS: National surveillance system data were compared to hospital discharge data. RESULTS: No statistically significant correlation between the number of cases of campylobacteriosis and Guillain-Barre syndrome (GBS) was found. There was no statistically significant correlation between the number of cases of campylobacteriosis, salmonellosis, shigellosis, and any of the categories of reactive arthritis; apart from two correlations with campylobacteriosis: with arthropathy associated with Reiter's disease and nonspecific urethritis (Pearson correlation R2=0.69; p<0.02) and unspecified infective arthritis (Pearson correlation R2=0.75; p<0.008). The later category is likely to include cases of both infective and non-infective aetiology. CONCLUSION: In New Zealand, infectious intestinal diseases are not making a significant contribution to the burden of hospitalisation for reactive arthritis or GBS.

Arthritis, Infectious↗

Estimating the impact of the next influenza pandemic on population health and health sector capacity in New Zealand.

AIM: To estimate the impact of the next influenza pandemic on population health and health sector capacity in New Zealand. METHOD: Population data for New Zealand was used with the software package 'FluAid' (CDC, Atlanta). Additional data was used to provide estimates of impacts on health sector capacity. RESULTS: For incidence rates in the 15% to 35% range for the first pandemic wave, the modelling results give a range of 1600 to 3700 deaths attributable to pandemic influenza. The estimated range of hospitalisations was between 6900 and 16,200. The estimated number of cases of illness requiring medical consultation ranged from 325,000 to 759,000. For the peak week of an 8-week epidemic (35% incidence scenario), it was estimated that 42% of all public hospital beds would be required at least for some proportion of the week and that the average general practitioner would be consulted by around 80 people with influenza. CONCLUSION: This modelling work has a number of limitations and so these results could still substantially over- or under-estimate the impact of the next influenza pandemic. Nevertheless, the potentially severe impact of pandemic influenza on population health and health sector capacity provides a strong case for health authorities to intensify preparatory efforts and to strengthen health sector infrastructure.

Computer Simulation↗

Infections, medication use, and the prevalence of symptoms of asthma, rhinitis, and eczema in childhood.

BACKGROUND: The "hygiene hypothesis" postulates that infections during infancy may protect against asthma and atopy. There is also some evidence that antibiotic and/or paracetamol use may increase the risk of asthma. METHODS: The study measured the association between infections, and medication use early in life and the risk of asthma at age 6-7 years. It involved 1584 children who had been notified to public health services with serious infections at age 0-4 years, and 2539 children sampled from the general population. For both groups, postal questionnaires were completed by parents. RESULTS: There was little difference in the prevalence of current wheezing between the childhood infections group (prevalence = 23.5%) and the general population group (prevalence = 24.3%). There was also little difference whether the major site of infection was gastrointestinal (prevalence = 24.1%), invasive (prevalence = 24.6%) or respiratory (prevalence = 21.1%). However, in both groups, there were associations with antibiotic (OR = 1.78, 95% CI 1.49 to 2.14) or paracetamol (OR = 1.38, 95% CI 1.04 to 1.83) use in the first year of life or recent paracetamol use (OR = 2.10, 95% CI 1.78 to 2.49) and current wheezing. There was a weak protective effect of childhood infections in children who had not used antibiotics in the first year of life (OR = 0.78, 95% CI 0.55 to 1.10). CONCLUSIONS: These findings are consistent with other evidence that antibiotic use early in life may increase the risk of asthma. They are also consistent with some preliminary evidence associating paracetamol use with an increased risk of asthma. Any protective effect of notifiable childhood infections was weak.

Acetaminophen↗

Sacroplasty: a treatment for sacral insufficiency fractures.

Sacral insufficiency fracture is a debilitating injury for which no active treatment is currently available. We present three consecutive cases of elderly patients with sacral insufficiency fractures whose symptoms were relieved immediately by treatment of the fractures by polymethylmethacrylate injections, a so-called sacroplasty.

Aged↗

The beneficial impact of Hib vaccine on disease rates in New Zealand children.

AIM: To examine the impact of Haemophilus influenzae type b (Hib) vaccine on the burden of Haemophilus influenzae (Hi) disease in New Zealand children aged under five years (under-5s). METHODS: Analysis of national mortality, hospitalisation, laboratory, and notification data. RESULTS: The introduction of Hib vaccine in 1994 led to a 92% decline (95%CI = 89 94%) in the hospitalisation rate of Hi meningitis for under-5s (1995 2000 compared to 1988 1993). Pre-vaccine, the Hi meningitis hospitalisation rate was 27 per 100 000 in the under-5s and this declined to 2 per 100 000. Even though Hi meningitis declined in all ethnic groups (eg down to 3 per 100 000 among Maori), there was a worsening of equity with the proportion of children hospitalised with Hi meningitis who were Maori increasing from 23% to 40% of all cases. The rate of epiglottitis hospitalisations also declined substantially (by 94%, 95%CI = 89 - 96%). CONCLUSIONS: Hib vaccination appears to be preventing at least 80 cases of meningitis and 30 cases of epiglottitis every year in under-5s in New Zealand. But the beneficial impact of Hib vaccination has been less for Maori and so there is a need for further improvements in immunisation coverage in those populations with the highest disease burdens.

Child, Preschool↗

A re-appraisal of the burden of infectious disease in New Zealand: aggregate estimates of morbidity and mortality.

AIM: To assess the aggregate burden of infectious disease in New Zealand in terms of mortality and hospital admissions. METHODS: New Zealand mortality records for the years 1980-1998, and hospital discharges for the period 1988-2000, were re-analysed using a recoding of ICD-9 codes to estimate the aggregate burden of infectious disease. The recoding scheme was modified, as in an earlier analysis, from that developed by Centers for Disease Control and Prevention. RESULTS: Following recoding, the proportion of deaths attributable to infectious disease increased from 0.7% of deaths to 6.6% of deaths. Likewise recoding of hospital discharges showed an increase in the proportion due to infectious disease from 2.2% to 12.6%, second only to "complications of pregnancy, childbirth and the puerperium". Over the study period infectious disease mortality rates have showed little decline, and there has been a nearly 60% increase in infectious disease hospital discharge rates. CONCLUSIONS: The findings confirm and extend those of an earlier study, indicating the substantial burden of disease that is still attributable to infectious disease in New Zealand. The burden remains inequitable.

Adolescent↗

Distraction of skeletal muscle: evolution of a rat model.

To better study the effects of limb lengthening on skeletal muscle, the authors developed a rat model that uses a miniature external skeletal fixator applied to the tibia of an adult Sprague-Dawley rat. The mounting and lengthening protocols follow the principles developed by Ilizarov. With the initial version of the fixator, the rats had progressive equinus contractures develop because the calf muscles resisted elongation. By incorporating a footplate in the distraction apparatus, tibial lengthening can be achieved without concomitant equinus.

Animals↗

Effects of distraction on muscle length: mechanisms involved in sarcomerogenesis.

Although a great deal of interest has been given to understanding the mechanisms involved in regulating the radial growth that occurs because of resistance training, much less has been given to studying the longitudinal growth of skeletal muscle that occurs because of passive stretch. The current authors provide a brief overview of key issues relevant to the longitudinal growth of skeletal muscle that occurs during distraction osteogenesis. Specifically, five key issues are addressed: (1) the pattern of sarcomerogenesis during distraction; (2) sarcomerogenesis and altered expression of sarcomeric and nonsarcomeric genes; (3) the satellite cell hypothesis; (4) mitogenic factors; and (5) new approaches for studying the longitudinal growth of skeletal muscle. A discussion is provided that revolves around the concept of a negative feedback loop. One of the most interesting issues to be resolved in muscle biology is the role of satellite cells in regulating the growth of skeletal muscle. Currently, it is not known whether satellite cell activation is a prerequisite for the longitudinal growth of skeletal muscle. Gene chip analyses provide a paradoxical view, showing that distraction osteogenesis results in the upregulation of a gene, GADD45, involved with growth arrest and deoxyribonucleic acid destruction.

Animals↗