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Biomedical subjects

N Pearce

Publications and source records attributed to N Pearce.

At least 37 records · Page 2Linked to original sources

Stomach cancer in New Zealand: time trends, ethnic group differences and a cancer registry-based case-control study.

Stomach cancer trends in New Zealand were examined. Age-standardized mortality and incidence rates have declined over the past four decades, as in other countries. Rates have been consistently higher for men, and for Maori. A cancer registry-based case-control study of 1016 male stomach cancer cases and 19,042 male controls with other cancers was also conducted, to evaluate the relationships between stomach cancer and specific occupations. Adjustment was made for age, ethnicity, socioeconomic level, and smoking status. When 22 occupational groups were examined, adjusted odds ratios (ORs) and 95% confidence intervals (95% Cls) were elevated above unity for only one group: forestry workers (OR 1.83, 95% Cl 1.01-3.32). When two large, heterogeneous groups were broken down into 15 subgroups, adjusted ORs and 95% Cls elevated above unity were found for three sub-groups: grain millers and related workers; brewers, wine and beverage makers; and field crop workers. These findings may be because of the multiple comparisons and subgroup analyses undertaken. Men who had ever smoked cigarettes were found to have an increased stomach cancer risk compared to those who had never smoked (adjusted OR 1.36, 95% Cl 1.15-1.60).

Case-Control Studies

Social class inequalities in the decline of coronary heart disease among New Zealand men, 1975-1977 to 1985-1987.

Coronary heart disease (CHD) is regarded as a disease of developed 'western' societies. Within developed societies, however, CHD is typically a disease of the less affluent socioeconomic classes. This has not always been the case. Forty years ago. CHD was reported to be more common among the upper social classes. In New Zealand, as in other developed countries, this original trend across social classes was reversed during the past 40 years. In 1975-1977, a gradient across social class was observed for both CHD and cerebrovascular disease mortality, with the lowest social classes experiencing the highest mortality. This study has now been repeated for the period 1985-1987. Employed males aged 15-64 years were categorized by the Elley-Irving scale into six social classes. The overall age-standardized mortality rate from CHD declined over the ten-year period, from 163.0 to 121.7 per 100,000 person-years. Over the same period, however, the social class gradient for coronary mortality actually increased. The overall age-standardized mortality rate from cerebrovascular disease also declined over the ten-year period, from 25.9 to 17.7 per 100,000 person-years. A social class gradient for cerebrovascular mortality was present in both periods. In contrast to coronary mortality, however, the social class gradient diminished slightly over the ten-year period.

Adolescent

Prescribed fenoterol and death from asthma in New Zealand, 1981-7: a further case-control study.

The association between inhaled fenoterol and death from asthma has been investigated further by studying 112 asthma deaths (cases) during 1981-7 in patients aged 5-45 years who had been admitted to a major hospital for asthma during the 12 months before death. Two age matched control groups were chosen. Control group A comprised 427 patients who had been admitted to hospital for asthma during the calendar year that the corresponding death occurred and who had also had a previous admission for asthma in the previous 12 months. Control group B comprised 448 patients admitted to hospital for asthma during the calendar year in which the admission of the corresponding case occurred. The inhaled fenoterol odds ratio was 2.11 (95% confidence interval (CI) 1.37-3.23, p less than 0.01) when group A was used as the control (the approach used in previous studies), and 2.66 (95% CI 1.74-4.06, p less than 0.01) with group B as the control (the approach recommended by critics of previous studies). Markers of chronic asthma severity were associated with asthma death when control group B was used, but not when control group A was used (which indicates that these markers were indirectly matched for when control group A was used). Information was also collected on various markers of acute asthma severity and prescription of psychotropic drugs, but it was found that these were not important confounders. These findings address the major criticisms of previous case-control studies of this issue, and add support to the hypothesis that inhaled fenoterol increases the risk of death in patients with severe asthma.

Administration, Inhalation

Lack of evidence for beta-2 receptor selectivity: a study of metaproterenol, fenoterol, isoproterenol, and epinephrine in patients with asthma.

In order to investigate the pharmacodynamic selectivity of a number of beta-receptor agonists currently used in asthma, we compared the pulmonary and extrapulmonary effects of repeated inhalations of epinephrine, fenoterol, isoproterenol, and metaproterenol in 12 patients with asthma in a randomized double-blind crossover study. The drugs were administered from metered-dose inhalers at 15-min intervals for five doses (total dose, 10 puffs of each compound). Measurements of heart rate, blood pressure, total electromechanical systole (as a measure of inotropic response), QTc interval, plasma potassium, and FEV1 were made 5 min after each dose and 30 min after the final dose. Fenoterol and metaproterenol had significantly greater inotropic, electrocardiographic, chronotropic, and hypokalemic effects than did both isoproterenol and epinephrine. There was no difference in the bronchodilating effect of metaproterenol, fenoterol, or isoproterenol although these agents caused a significantly greater increase in FEV1 than did epinephrine. The concept of increasing beta-2 selectivity for metaproterenol and fenoterol compared with isoproterenol are not supported in the clinical setting.

Adrenergic beta-Agonists

A comparison of the haemodynamic and hypokalaemic effects of inhaled pirbuterol and salbutamol.

In this double blind study, the cardiovascular and hypokalaemic effects of equal doses of inhaled pirbuterol and salbutamol were compared in eight healthy volunteers. Increasing doses of 200, 400, 600 and 800 micrograms (total dose 2000 micrograms) were given from a metered dose inhaler at 15 min intervals, followed by measurement of heart rate, blood pressure, total electromechanical systole (QS2I) (as a measure of inotropic response) and plasma potassium (K+) concentration 15 min after each inhalation. After inhalation of the highest concentration, salbutamol resulted in a greater increase in heart rate (10.5 bpm vs 4.4 bpm, p less than 0.0007), and reduction in QS2I (-25.4 ms vs -9.6 ms, p less than 0.0001) than pirbuterol. There were no significant differences in changes in systolic blood pressure (1.9 mmHg vs 6 mmHg, p = 0.27), diastolic blood pressure (-5.8 mmHg vs -3.9 mmHg, p = 0.64) or plasma K+ (-0.21 mmol/L vs -0.15 mmol/L, p = 0.57). We conclude that the new beta-2 adrenergic agonist pirbuterol is at least as beta-2 selective as salbutamol when administered by repeated inhalation in healthy volunteers.

Administration, Inhalation

Trends in asthma mortality in New Zealand, 1908-1986.

Trends in mortality from asthma in non-Maori New Zealanders aged 5 to 34 years were examined for the period 1908-1986. Two previously documented epidemics of death from asthma occurred in the 1960s and the late 1970s. These epidemics are most likely to have been due to changes in the management of asthma: the introduction of isoprenaline forte by metered dose inhaler in the 1960s and inhaled fenoterol in the 1970s. A previously unreported rise in mortality, which was more gradual in onset and less severe, occurred in the 1940s and 1950s; a similar pattern occurred in England and Wales during the same period. It is unlikely that this increase in mortality was solely due to changes in diagnostic fashion or disease coding. Possible explanations include changes in the management or prevalence of asthma, or in environmental factors. It is notable that mortality was below 0.5 per 100,000 person-years prior to 1940, but has subsequently increased considerably. Thus, while modern methods for treating asthma have improved the quality of life of many asthmatics, mortality has increased during the period of their introduction and use.

Adolescent

The self-administration of inhaled beta agonist drugs during severe asthma.

Interviews were conducted with 101 consecutive adult patients admitted to Wellington Hospital with a diagnosis of asthma to assess the extent to which beta agonist drugs are self-administered by asthmatic patients during severe asthma. The 99 patients prescribed an inhaled beta agonist were subdivided into two groups: group A comprising 79 patients prescribed a beta agonist for inhalation via an inhaler (metered dose aerosol or dry powder device) alone; group B comprising 20 patients prescribed beta agonist for inhalation via both an inhaler and nebuliser. In group A, the attacks of asthma lasted greater than 24 hours in 64/79 patients, and 22% of these patients reported taking more than 60 doses of their inhaler, and 52% more than 30 doses during the 24 hr period prior to admission. In group B, the attacks of asthma lasted greater than 24 h in 17/20 patients, and 35% of these patients self-administered their nebuliser more than six times, and 76% more than four times during the 24 h period prior to admission. In addition to their nebuliser use, these patients also took a median 23 doses of their inhaler during this 24 h period. This use of inhaled beta agonist contrasts with the recommended practice in both the USA and Europe, where most physicians recommend no more than 15 doses of a beta agonist as the maximal dose per day. We conclude that asthmatic patients in New Zealand self-administer high doses of inhaled beta 2 agonist drugs during severe exacerbations of asthma.

Adolescent