Validation of coronary heart disease hospital discharge data

Data from a 1983 Auckland coronary heart disease register applying current World Health Organization criteria have been used to validate routine hospital discharge data. The register contained 905 patients under 65 years admitted to hospital and 858 of these patients were matched with hospital discharge records. Of the registered definite myocardial infarction cases 86% received the International Classification of Diseases code 410 (acute myocardial infarction); 9% of these cases received a code 411-414 (other forms of coronary heart disease or angina) and 5% received other codes. Only 405 of the 604 cases (67%) coded 410 in the hospital discharge data were true definite myocardial infarctions according to the World Health Organization criteria. The routine hospital International Classification of Diseases data do not provide diagnostic groups sufficiently close to World Health Organization categories for them to be used alone to monitor trends in coronary heart disease morbidity rates.

Underestimation of relative weight by use of self-reported height and weight

Self-reported and measured height and weight were obtained from a representative sample of 1,598 persons in Auckland, New Zealand during 1982. The accuracy of the self-reported data and its effect on the misclassification of relative weight, as measured by Quetelet index, were examined. The finding that for most participants (75%), self-reported measures were no more than 3.5 cm from their measured height and 2.4 kg from their measured weight indicates that self-reports have a high degree of accuracy. However, the participants consistently overestimated their height and underestimated their weight, resulting in an underestimation of relative weight. This would have little effect on analyses using the self-reported relative weight measures as a continuous covariate, but misclassification would occur when using relative weight as a categorical variable. The sensitivities and specificities associated with categorized self-reported relative risks that have been calculated from relative weight derived from self-reported height and weight.

Has the long term prognosis following myocardial infarction improved?

Coronary heart disease mortality in New Zealand has declined by 25% in the 15 years since 1968. One possible explanation for this decline is lower case-fatality rates resulting from improvements in the management of myocardial infarction. This paper tests this hypothesis by examining trends in three year survival following a definite myocardial infarction for the population aged 35-69 in Auckland. The data were obtained from two methodologically identical population-based registers of myocardial infarction compiled in Auckland in 1974 and 1981. The three year survival rates were 59% and 65% for the two time periods respectively and this difference did not reach statistical significance. However, as the survival curves appear to be diverging, there may have been a small improvement in long term outcome after myocardial infarction.

Cystic fibrosis in New Zealand: incidence and mortality

The incidence of and mortality from cystic fibrosis in New Zealand from 1960 to 1983, has been reviewed. Cystic fibrosis subjects have been located from data obtained from New Zealand paediatricians, the Cystic Fibrosis Association and hospital admission records. Mortality figures in the years 1960-1982 were also obtained. The incidence of cystic fibrosis of 1: 3179 non-Maori births was similar to that reported previously. Those born during 1970-1983, have a significantly better survival than those born before 1970. The survival figures are similar to those in England and Wales, but are considerably lower than those reported from Canada, or cystic fibrosis centres in the United States and Australia.

Muscle fluorometry: a determination of the depth of penetration

Fluorometric recordings of NADH (nicotinamide adenine dinucleotide) were made on rabbit papillary muscles. The specimens were placed between the UV light source and a small window of the detection stage. As the muscle was moved over the window in a transverse direction, simultaneous measurements could be taken of transmitted UV light and fluorescent light for various thicknesses of tissue. It is concluded that a muscle thickness of 0.65 mm is optimal before absorption of the incident light decreases the fluorescence signal.

Psychometric characteristics of the aberrant behavior checklist

Information was presented on the psychometric characteristics of the Aberrant Behavior Checklist. The internal consistency and test-retest reliability of the Checklist appeared to be very good. Interrater reliability tended to vary across raters and subscales and ranged from mediocre to good but was generally in the moderate range and acceptable for research purposes. Validity was assessed by comparing Checklist scores for residents presenting with attributes thought to reflect varying degrees of social adaptation. Validity was also evaluated by comparing Aberrant Behavior Checklist scores with ratings on adaptive behavior scales and with objective observations of behavior. In general, validity was established for most Aberrant Behavior Checklist subscales. Preliminary data from drug investigations suggested that the Checklist may provide a useful adjunct for the assessment of psychotropic drug effects.

The aberrant behavior checklist: a behavior rating scale for the assessment of treatment effects

The development of a scale to assess drug and other treatment effects on severely mentally retarded individuals was described. In the first stage of the project, an initial scale encompassing a large number of behavior problems was used to rate 418 residents. The scale was then reduced to an intermediate version, and in the second stage, 509 moderately to profoundly retarded individuals were rated. Separate factor analyses of the data from the two samples resulted in a five-factor scale comprising 58 items. The factors of the Aberrant Behavior Checklist have been labeled as follows: (I) Irritability, Agitation, Crying; (II) Lethargy, Social Withdrawal; (III) Stereotypic Behavior; (IV) Hyperactivity, Noncompliance; and (V) Inappropriate Speech. Average subscale scores were presented for the instrument, and the results were compared with empirically derived rating scales of childhood psychopathology and with factor analytic work in the field of mental retardation.

Myocardial infarction and sudden death in Auckland

A population-based register of definite myocardial infarction and sudden death was established in Auckland for the twelve months from 1 March 1981. Data were collected on 905 myocardial infarctions and 300 sudden deaths that occurred in people under the age of 70 years. The age standardised event rates were more than three times higher in men than in women. The rates of myocardial infarction were comparable in Maoris and non-Maoris but the sudden death rate was almost three times higher in Maoris than in the other ethnic groups. The age standardised 28 day myocardial infarction case fatality rates were 27% and 21% for men and women respectively. Overall, 42% of patients who reached hospital were transported by a life support unit, and 59% of patients who reached a coronary care unit did so within four hours of onset.

Trends in survival after myocardial infarction in New Zealand, 1974-81

Coronary heart disease mortality in New Zealand has declined by 20% in the 13 years since 1968. One possible explanation for this decline is lower case-fatality rates resulting from improvements in the management of myocardial infarction. This paper tests this hypothesis by examining trends in 1-year survival following a definite myocardial infarction for the population aged 35-69 in Auckland. The data were obtained from two methodologically identical population-based registers of myocardial infarction compiled in 1974 and 1981 in Auckland. In both periods the 1-year crude case-fatality rate was 30% and the pattern of survival over 1 year was similar. These data suggest that factors other than the improved care of myocardial infarction patients are responsible for the decline in coronary heart disease mortality rates in New Zealand.

Blood pressure levels and the treatment of hypertension in Auckland, 1982

The level of coronary heart disease risk factors in a random sample of 1598 people aged 35-64 years was examined in Auckland in 1982. Blood pressure was measured and the prevalence of treated and untreated hypertension determined. Mean systolic blood pressure increased with age from 124 mmHg (16.49 kPa) in men aged 35-39 years to 144 mmHg (19.15 kPa) in those aged 60-64 years, and from 115 mmHg to 140 mmHg (15.29-18.62 kPa) in women in the same age groups. Compared with previous New Zealand studies blood pressure levels were lower in this study and considerably more people were on antihypertensive treatment. Hypertension is still a major problem in Auckland with 21% of men and 19% of women aged 35-64 years either hypertensive or on antihypertensive treatment. Although half of these people were on treatment, 16% of men and 9% of women in this age group in Auckland were estimated to have a blood pressure level in the hypertensive range.

Sex differences in subsite incidence of large-bowel cancer

A review of patients with large-bowel cancer at a major New Zealand hospital showed an excess of right-sided colonic tumors in females compared with males. These observations stimulated analysis of the National Cancer Registry registration data for large-bowel cancer for the whole of New Zealand in the years 1972 to 1975 (4678 patients). Rates for each site were calculated and age-standardized, using world population figures. The findings confirmed that females have a higher incidence of right-sided colonic cancer and males a higher incidence of rectal cancer and showed a significant trend in this direction from the ascending colon toward the rectum. The observed differences between males and females suggest differences in the etiology of the tumor and should be taken into account in assessing modalities and outcomes of treatment.

Cancer of the pancreas in New Zealand 1970-1974

There were 991 new cases of cancer of the exocrine pancreas in the New Zealand population for the five years 1970-74. The disease had a higher incidence in men than women and in Maoris compared to Europeans. There was no increase in incidence in the period 1950-52 to 1971-73. Most of the cancers occurred in the head of the pancreas and were described as adenocarcinomas. Seventy seven per cent of the patients had lymph node metastases or advanced disease at the time of diagnosis. Only 7 per cent were able to have resectional surgery and in 90% specific therapy was not given. The estimated crude three-year survival rate of all patients was four per cent and the median survival time was 1.7 months. The crude three year survival rate after resection was 9.8% and the median survival time was 5.8 months. The most important variables affecting survival were stage of disease and age of patient.

Cancer of the stomach in New Zealand: 1970-74

A total of 1,891 new cases of cancer of the stomach occurred in New Zealand (1971 population 2,862,631) in the five years 1970-74. There was a higher incidence in men than women and in Maoris compared to Europeans. The disease had declined in incidence by about 50% in 20 years. Most of the cancers occurred in the distal stomach and were described as adenocarcinomas. Seventy percent of the patients had a lymph node metastases or advanced disease at the time of diagnosis. Only 39% were able to have resectional surgery and in 57% specific therapy was not given. The estimated crude five year survival rate of all patients was 7.8% (relative rate 10.2%) and the crude five year survival rate after resectional surgery was 18.7% (relative rate 24.7%). The most important variables affecting survival were the stage of the disease and the age of the patient.

Analytical errors in clinical laboratories as assessed by an interlaboratory survey

Combined errors ar the commonest systematic errors in laboratory results and occur with most tests studied. In these errors, results are reduced (or, less commonly, increased) by a factor, and this effect is compensated by the addition (or subtraction) of a constant amount. The effect is that results are in error in opposite direction at high and low levels. Inconsistency is predominant and is due mainly to imprecision, although for some tests (iron, cholesterol, calcium, and triglycerides among those studied) other factors such as non-specificity are significant. An interlaboratory survey based upon external method assessment using linear regression analysis provided objective information about analytical error in laboratories which is not usually obtained, while at the same time meeting the usual functions of surveys in the quality audit of performance.

The association between diabetic retinopathy and skeletal muscle capillary basal lamina thickening corrected for the influence of age and duration of diabetes

The association between an objective measure of diabetic retinopathy and skeletal muscle capillary basal lamina thickness was examined in a group of 30 male insulin-treated diabetic subjects, mean age (+/- SD) 44.6 +/- 13.2 yr, duration of diabetes 21.2 +/- 11.2 yr, % ideal body weight (% IBW) 106 +/- 11%. In addition, muscle capillary basal lamina width was measured in a group of 18 nondiabeitc men, mean age 40.7 +/- 16.3 yr and % IBW 118 +/- 23%. The muscle capillary width of the diabetic subjects was significantly greater than that of the nondiabetic group (P less than 0.01), but the values of the two overlapped considerably. In the diabetic group, there was a significant association of basal lamina width with age (P less than 0.01) but not with duration of diabetes. The association between extent of retinopathy and muscle capillary basal lamina width was not strong. The findings of the study do not therefore support the use of an estimate of muscle capillary basal lamina thickness as a single representative measure of diabetic microangiopathy.

Cancer of the large bowel in a defined population: Canterbury, New Zealand, 1970--4

A total of 1024 new cases of cancer of the large bowel occurred in Canterbury, New Zealand (population 400,796), in the 5 years 1970--4. Of these, 992 were diagnosed before death and are reviewed in this paper. The high incidence of this disease in New Zealanders of European origin is illustrated. A significant difference in site distribution of primary tumours between the sexes was found, with a female preponderance of cancer of the proximal colon gradually changing to a male preponderance of cancer of the rectum. In all, 61.5 per cent of the patients had lymph node metastases or advanced disease at the time of diagnosis or treatment. Largely as a consequence of this, only 65 per cent were able to have potentially curative treatment. The estimated crude 5-year survival rate of the whole group was 32.7 per cent (relative rate 42.8 per cent) and the crude 5-year survival rate after potentially curative surgery was 48.4 per cent (relative rate 62.4 per cent). The results are compared with those of other authors. They emphasize the generally unsatisfactory outcome of treatment.

Increased numbers of heat-resistnat spores produced by two strains of Clostridium perfringens bearing temperate phage s9

Sporulation kinetics and spore heat resistance data were compared for a lysogenic strain of Clostridium perfringens, s9, before and after curing with ultraviolet irradiation. The cured strain showed the same growth rate in broth media as the lysogenic strain but took 6 h longer to form refractile spores. For lysogenized and cured strains the percentages of refractile spores produced that were heat-resistant (80 degrees C for 15 min) were 50 and 0.2, respectively. When reinfected with the temperature phage, the cured strain produced spores in 2 to 3 h, like the original lysogenic culture, and 10% of the spores produced were heat-resistnat.

Vitamin C status of elderly men in a residential home

The vitamin C status of 35 men, over 70 years of age from a residential home has been studied by measuring the plasma and leucocyte vitamin C levels and by assessing the intake of vitamin C. The mean plasma vitamin C level of the group was 16 +/- 15 mumol/l which was significantly lower (P less than 0.005) than that of a similar group of elderly men living alone (26 +/- 20 mumol/l). The mean leucocyte vitamin C levels of the two groups did not differ significantly. Twenty-nine (83 percent) of the institution group had plasma vitamin C levels below 23 mumol/l and 13 men (37 percent) had leucocyte vitamin C levels below 10 microgram/10(8)WBC. The residents who supplemented the institution diet with their own fresh fruit supplies had higher plasma and leucocyte vitamin C levels than the men who did not (P less than 0.01). Some clinical signs possible related to vitamin C deficiency were recorded but these could not later be statistically related to either plasma or leucocyte vitamin C levels. A case is made for vitamin C supplementation of puddings in institutional meals for the elderly.

Nutrition of elderly men living alone. Part 2, Vitamin C and thiamine status

A dietary survey using the five day record method was carried out on 35 elderly men living alone in the Christchurch area. The mean calculated intake of vitamin C for these men was 31 mg/day. These dietary intakes of vitamin C were significantly correlated with both plasma vitamin C levels and with leucocyte vitamin C levels. Twelve men (34 percent) with lowered dietary intakes of vitamin C were in the range for asymptomatic scurvy. The mean calculated intake of thiamine was 1.05 mg/day. The mean TPP effect was 12.9 percent (n = 27). Dietary intakes of thiamine showed a significant inverse relationship with TPP effect. Eight subjects (23 percent) who too, less than the Australian dietary allowance had an elevated TPP effect. By both dietary and biochemical methods there was evidence of subclinical vitamin C and thiamine deficiencies in more than a quarter of these men.

Vitamin C concentration in plasma and leucocytes of men related to age and smoking habit

Morning plasma and leucocyte vitamin C concentrations were measured in 178 healthy men aged 17-68 years. In the youngest age group (17-29 years), smokers had significantly lower plasma (P less than 0.01) and leucocyte (P less than 0.001) vitamin C levels than non-smokers. With advancing age plasma and leucocyte vitamin C levels of non-smokers appeared to decline. The lower levels in younger smokers did not significantly alter in the later decades. There was no significant difference between the plasma or leucocyte vitamin C levels of smokers and non-smokers in the decade 60-69 years.