Access to coronary catheterisation: fair shares for all?

OBJECTIVE

To determine the effects of patient's sex and area's material deprivation on utilisation rates of coronary catheterisation and angiography in the investigation of ischaemic heart disease.

DESIGN

Retrospective analysis of routinely collected hospital statistics.

SETTING

Acute hospitals throughout Northern Ireland.

SUBJECTS

24,179 episodes of patients discharged from hospital with a primary diagnosis of ischaemic heart disease and 1270 episodes relating to patients with an underlying diagnosis of ischaemic heart disease who had either coronary catheterisation or angiography.

MAIN OUTCOME MEASURES

Age standardised admission rates for heart disease and age standardised utilisation rates for catheterisation or angiography, or both, for 566 electoral wards ranked by Townsend "deprivation" scores.

RESULTS

Catheterisation-angiography rates in men were over fivefold those of women, ranging from 85.5/100,000 v 16/100,000 in patients from "well off" areas to 123/100,000 v 22/100,000 for patients from deprived areas. After admission rates for heart disease were controlled for, the overall rate ratio for women was 0.48 (95% confidence interval 0.38 to 0.60). After differential admission rates for heart disease and other potential clinical confounders were controlled for, the investigation rates of patients from the least and most "deprived" areas were not significantly different (rate ratio 1.04 (0.87 to 1.25)).

CONCLUSION

Although investigation rates were significantly lower in women than in men, further clinical data would be required before labelling this underutilisation as evidence of bias. There was no significant difference in invasive investigation rates for heart disease in areas of varying deprivation or affluence.

Referrals for coronary angiography in a high risk population

OBJECTIVES

To examine variations in referral for coronary angiography within Northern Ireland and relate these to local death rates from coronary artery disease (ICD rubrics 410-414).

DESIGN

A descriptive retrospective analysis of aggregate hospital activity data for 1979-88 and corresponding mortality rates in the local population.

SETTING

Two regional referral hospitals and 26 local district council areas.

PATIENTS

5173 patients aged 35-74 years with an underlying diagnosis of ischaemic heart disease, whose records contained complete information on their age, sex, and home address.

MAIN MEASURES

Age-standardised angiography rates and corresponding standardised death rates derived from the registrar general's reports.

RESULTS

Among the 26 constituent district council areas there was significant heterogeneity in the angiography rates, ranging from 62 to 335/100,000 in men and from 7 to 62/100,000 in women (likelihood ratio statistic 856 and 359 respectively). There was no significant association between these angiography rates and the local death rates from ischaemic heart disease.

CONCLUSION

The results suggest a non-uniform threshold for referral for angiography.

IMPLICATIONS

Clinicians need to examine the appropriate indications for referral for invasive investigation.

Deletion polymorphism in angiotensin-converting enzyme gene associated with parental history of myocardial infarction

In a European study an insertion (I)/deletion (D) polymorphism in the angiotensin converting enzyme (ACE) gene has been shown to be associated with the risk of myocardial infarction (MI). In the same study, we investigated the association of the polymorphism with a parental history of fatal MI. There was an excess of both DD (odds ratio 2.6, p = 0.02) and ID (odds ratio = 1.9, p = 0.08) genotypes among those having a parental history of MI, confirming that genetic variation in the ACE locus could be involved in the risk of MI.

Evaluating the breast screening programme: the need for surgical audit

It is to be anticipated that a reduction in population mortality attributable to mammographic screening would be heralded by an increasing proportion of breast cancer cases diagnosed at earlier stages and by an improvement in case fatality. Few cancer registers routinely produce incidence or survival data by stage at diagnosis and thus improvement in these will be the harder to assess. By thorough casenote review and follow up, this study has determined the usual presentation and survival of breast cancer in Northern Ireland in 1986 before the introduction of screening. Overall, 85% of cases were Manchester stage I or II, figures which accord with other British studies. Five-year survival ranged from 77.8% for stage I (95% confidence limits 71.7%, 82.7%) to 35.7% for stage IV (95% confidence limits 13.0%, 59.4%). Forty-three per cent of cases treated in non-teaching hospitals could not be pathologically staged, more than twice the figure for teaching hospitals (Chi-squared = 15.7, df = 1, P < 0.001). Since many tumours not detected by screening will be treated outside teaching centres, this difference will reduce the statistical power to detect the true shift in stage distribution and improvement in survival from screening. Comprehensive surgical audit would help to resolve the inadequacies in existing data collection and improve the ability to evaluate the outcome of the screening programme.

Enhancing mammography uptake: who do women listen to?

Previous work has established that women who attend for mammography differ from non-attenders in a number of socio-demographic and attitudinal characteristics. The present study was conducted to determine whether women who attended for mammography differed from non-attenders in a number of key areas: (1) in how they obtained information about screening; (2) in their understanding of the disease and basic screening precepts; and (3) in the extent to which they perceived their general practitioners (GPs) and other members of the primary case team, such as practice nurses, had actively promoted the programme. Three hundred attenders and 300 non-attenders were interviewed in their own homes using a structured questionnaire. Only 5% of women interviewed had ever asked their GP for any advice about breast screening, and only 18% recalled their family doctor every discussing or raising the subject with them. Although attenders and non-attenders differed significantly in their understanding of the scope and purpose of screening, both groups obtained information more often from friends and relatives and broadcast media than from official sources. Attenders were more likely to cite material in the GP's surgery as an important source of information (chi 2 = 5.1, p = 0.02). Attenders were marginally more likely than non-attenders to have previously attended a well-woman clinic in primary care (chi 2 = 3.1, p = 0.08) and were more likely to say that such clinics were being offered by their family doctor (chi 2 = 9.8, p = 0.008).(ABSTRACT TRUNCATED AT 250 WORDS)

Trends in the relative frequency of histologically diagnosed epithelial dysplasia and intra-oral carcinoma in Northern Ireland, 1975-1989

Trends in the incidence of histologically diagnosed dysplastic lesions of the intra-oral mucosa have been investigated for the period 1975-89 in a well defined population of 1.5 million. These have been contrasted and compared with trends in the incidence of intra-oral carcinoma. Cases were ascertained from the records of all the histopathology laboratories that serve the Northern Ireland population. Over the 15-year period, there were 135 cases of histologically diagnosed epithelial dysplasia. In contrast to the significant increase in the incidence of intra-oral carcinoma, there was no significant change in the annual age standardised incidence of dysplastic lesions over the period. The ratio of malignant to dysplastic diagnoses rose from 2.5:1 to 5.4:1. Only 24 of the dysplastic lesions were known to have subsequently progressed to malignant carcinoma, representing 4.5% of all invasive tumours diagnosed during 1975-89. The results highlight a number of unresolved issues regarding the natural history of intra-oral carcinoma.

Trends in the incidence of histologically diagnosed intra-oral squamous cell carcinoma in Northern Ireland, 1975-89

Studies in Britain point to a rise in the incidence of intra-oral cancer in the last 20 years, paralleling trends evident in other European countries. Cases of histologically-diagnosed primary intra-oral squamous cell carcinoma have been ascertained by reviewing the records of pathology departments in Northern Ireland. Trends in the incidence of the disease have been determined for the period 1975-89. There has been a significant increase in the incidence among men, rising from 1.78 to 3.14 per 100,000. In women over the same period the incidence rose from 0.87 to 1.19 per 100,000, but this change was not significant. These trends concur with recent findings from other countries.

Attitude or access: reasons for not attending mammography in Northern Ireland

Maximizing the uptake of mammography among the eligible population will be critical to the success of the national breast cancer screening programme. Although compliance may vary for different reasons from area to area, it has been suggested that making screening clinics more accessible may be an effective means of enhancing uptake. In the present study we undertook 600 interviews with women who had been invited for mammography to determine the main reasons given by women in Northern Ireland for not attending for mammography when invited, how these may have related to access factors and to discover their views on how the service might be improved. The most frequently cited reasons for non-attendance were related to feelings of indifference or ignorance of screening issues and to fear of pain or embarrassment. Although more non-attenders did not have access to private transport, few women (23/600) expressed a preference for more accessible clinics. The fact that non-attenders were more likely not to have had a recent cervical smear, adds weight to the notion that attitudes rather than access played the predominant role in influencing uptake in this sample. We have concluded that investment in flexible mobile screening units cannot replace the continued need for delivering effective advocacy to eligible women.

Families at risk of colorectal cancer: who are they?

The first degree kinships of 305 index cases have been studied to determine whether an early age of onset or a particular site distribution characterizes familial aggregations of colorectal cancer. The probands comprised 100 patients aged 55-74 years and 205 patients under 55 years at diagnosis and were drawn from a large population database. Ascertainment and verification were complete for 2566 of 2657 first degree relatives. The history of cancer in 296 relatives was validated in 96% of cases from medical or other records. Among kinships ascertained through index cases under 55 years of age, less than 5% had three or more individuals affected by colorectal cancer. The comparable proportion of older probands' families was 3%. Probands with proximal disease were no more likely to have a positive family history of bowel cancer than those with disease distal to the splenic flexure. These findings are consistent with other population based studies of the epidemiology of familial colorectal cancer but contrast with reviews from referral centres and family cancer clinics.

Do general practitioners facilitate the breast screening programme?

Mammography uptake has been discouragingly low since the introduction of breast cancer screening in Northern Ireland. This questionnaire survey was undertaken to appraise the views of participating general practitioners (GPs) about mammography and the extent to which they followed good practice in facilitating the screening programme. Of 173 GPs, 152 returned a questionnaire. Approximately three-quarters of these GPs believed the screening programme was worthwhile for the eligible women on their list. When sent the prior notification lists from the screening unit, less than half of the GPs always checked the accuracy of patients' addresses. Fifty-five per cent of the GPs said they routinely took opportunities (as they arouse) during normal surgeries to counsel women about mammography and 90% did so in health promotion or well-woman clinics. Despite this, only 56% routinely recorded non-attendance in patients' case notes and less than 20% contacted non-attenders to advocate mammography. Such a pro-active approach was more commonly adopted with women who had not attended when invited for a cervical smear. There was no significant difference in mammography uptake among the women on the lists of GPs with differing views or whose doctors differed in their degree of active commitment to the programme. The results point to a need for the screening unit to evaluate its own advocacy role to GPs and for Health Board to devise effective appraisal strategies for health promotion clinics in primary care.

Colorectal cancer and ischaemic heart disease: an uncommon inheritance!

This study reports the relative risk of death from cancer and from coronary artery disease in 1,811 first-degree relatives of 205 young colorectal cancer probands. The elevation in the risks of death from cancer (eg colon 3.6; rectum 2.0; uterus 1.8; cervix 2.3) is consistent with, though of lower magnitude than previous studies. An unexpected find was a highly significant deficit in coronary deaths. Recently discovered molecular associations between colon cancer and cholesterol metabolism suggest that further family studies of bowel cancer and heart disease in a variety of populations may be worthwhile.

Confidence intervals and interval cancers ... needles and haystacks?

The measurement of interval cancer rates will be critical to the successful evaluation of the breast cancer screening programme. The number of interval cancers expected in a district will depend on the population size, the test sensitivity and the background incidence of breast cancer. The present study was undertaken to measure the incidence of breast cancer in Northern Ireland, and to assess the practical problems that might be encountered in ascertaining interval cancers. Given a local yearly incidence of 182/100,000, only 14 interval cancers per year might be expected in Northern Ireland (population 1.5 million). The completeness of the local cancer register would not ensure reliable detection of this relatively small number of tumours. To give larger samples sizes and thus narrow the confidence intervals of measured rates, the results from several smaller regions could be aggregated. Different regions may have different mechanisms of ascertainment and this may make the interpretation of these rates more difficult.

Geographical variations and recent trends in cancer mortality in Northern Ireland (1979-88)

Cancer mortality in the 35-74 year age-range for selected sites during the period 1979-88 was investigated for the 26 district council areas of Northern Ireland. Trends in rates during the period were also studied and compared with trends in an earlier period, and with trends reported from the rest of the United Kingdom. Statistically significant differences between the age-standardised death rates in the 26 areas were observed for stomach cancer (women only), pancreatic cancer (women only), lung cancer (men and women) and for all cancers (men and women). Some evidence of spatial aggregation of rates was apparent for ovarian cancer even though rates in the 26 areas did not differ significantly. The patterns are illustrated with maps and some difficulties of interpretation are discussed. Mortality rates for oesophageal cancer increased during the period in both sexes while rates for stomach cancer decreased. Colon cancer rates increased significantly only in men, while an increase in lung cancer rates was confined to women. The mortality from all cancers increased significantly during the period by 0.8% per annum in men and 0.9% per annum in women. These trends were found to be broadly comparable with those reported elsewhere in the United Kingdom.

How prevalent is cancer family syndrome?

Based on an established but pragmatic definition of cancer family syndrome as the presence of three or more relatives affected by colorectal cancer in a first degree kinship, the contribution of this syndrome to the total cancer burden in Northern Ireland has been studied by investigating all non-polyposis probands under 55 years old at histological diagnosis between 1976 and 1978. Family interviews were possible for 95% (n = 205) of all non-polyposis probands and verification of vital status or medical history was obtained for 98% of 1811 first degree relatives. The prevalence of cancer family syndrome was between 1 and 2%, a figure some fivefold less than that estimated elsewhere. A proximal tumour excess was not characteristic of the ascertained families. These results may have implications for the identification of susceptible people if screening for high risk groups is considered a worthwhile option for reducing colorectal cancer mortality in the United Kingdom.

Prognosis in familial non-polyposis colorectal cancer

Familial cases of non-polyposis colorectal cancer have attracted much interest but little is known of their natural history. Using a population based study we have determined whether a positive family history of bowel cancer is an independent prognostic factor. All patients under 55 years with histologically confirmed colorectal cancer in Northern Ireland during the period 1976-8 were studied. The family history was validated in 95% of all nonpolyposis cases (n = 205). Medical history or cause of death were verified for 98% of 1811 first degree relatives. The strength of the family history was assessed using a score that compares the mortality from bowel cancer in the family against the average population mortality, taking account of family size and age structure. The family history score was not predictive of survival neither in univariate analysis or in a Cox's proportional hazards multivariate analysis controlling for age, sex, stage, site, and duration of symptoms. In conclusion, a positive family history does not independently influence prognosis in patients with bowel cancer.

Histologic characteristics and outcome of familial non-polyposis colorectal carcinoma

Familial cases of non-polyposis colorectal cancer have recently attracted much interest. Little is known about the characteristic histology or natural history of disease in such cases. Our aim was to determine, through a population-based study, whether mucin-secreting tumours were associated with a positive family history and whether 'familiality' was an independent prognostic variable. All patients under 55 years of age with histologically verified colorectal cancer in Northern Ireland during 1976-78 were studied. The family history was validated in 95% of all non-polyposis cases (n = 205), and the proband's histologic specimen reviewed in over 99%. Mucin-secreting tumours were significantly associated with a positive family history, but familiality was not found predictive of survival in a multivariate analysis controlling for age, sex, stage, site, symptom duration, differentiation, and histologic type.

Incidence and site distribution of colorectal cancer in Northern Ireland

Death rates from colorectal cancer in Northern Ireland are higher than in most of the rest of the United Kingdom. Although local surgeons have recognised this problem for some time it has remained unclear whether this reflects a greater underlying incidence or a worse mortality. We have reviewed all histological diagnoses of colorectal cancer in the province over a three year period and we report the incidence and site distribution for this disease in this population of one and a half million. With the exception of rectal cancer in females the incidence of colorectal cancer, whether histologically diagnosed or registered, is higher than in England, Wales or Scotland. The site distribution accords with that in other high risk countries. These results indicate that Northern Ireland has the highest underlying incidence of colorectal cancer in the United Kingdom.

Colorectal cancer in the north and south of Ireland 1950-1984

STUDY OBJECTIVE

Northern Ireland has the highest standardised mortality ratios for colon cancer in the United Kingdom and the Republic of Ireland has some of the highest mortality rates for cancer in the world. The aim of the study therefore was to investigate trends in colorectal cancer in the north and south of Ireland over the period 1950 to 1984.

DESIGN

The study was a cohort analysis of deaths from colorectal cancer for ages 35-74 years by five year age groups, divided by sex.

SETTING

This was a population study involving all cases reported to the Registrar General of Northern Ireland and the Eire Vital Statistics and Central Statistical Office during the study period.

MEASUREMENTS AND MAIN RESULTS

As in mainland Britain, rectal cancer mortality declined in the north and the south during the study period, but the fall began sooner for males than females. Colon cancer mortality fell in the late 1950s but subsequently rose to its previous high levels.

CONCLUSIONS

The observation that there were declines in mortality in the north and south of Ireland in the late 1950s does not support the hypothesis that altered diet due to war rationing in Great Britain and Northern Ireland underlay the fall in British colon cancer mortality after the war. The very high standardised mortality ratios for colon cancer in Northern Ireland highlight a continuing major public health problem in the region.

Hepatitis B screening in a northern Irish mental handicap institution: relevance to hepatitis B vaccination

The current DHSS guidelines on immunisation against hepatitis B in mental handicap hospitals recommend vaccination for personnel at risk directly involved in patient care (who may have direct contact with patients or their body fluids) and for new admissions into institutions where the incidence is known to be high. We report a serological survey of hepatitis B markers in over 99% of the residents of a large mental handicap hospital. Of 720 patients tested only one carried hepatitis surface antigen. This patient was anti-HBe positive. Only 4.5% of the residents carried any hepatitis marker. These results do not suggest the need for a local vaccination programme for patients or staff.

Risk management, public policy and informed consent: a case study

The present guidelines on the use of hepatitis B vaccine in mental handicap hospitals dictate the need for an a priori identification of occupational risk, but fail to clarify how this risk should be defined. The ethical requirement of a respect for autonomy however demands that in offering vaccine as a means of protection, the choice of options must be "informed'. The determinants of institutional transmission have not been clearly defined and it is therefore difficult to inform client groups as to the degree or nature of their occupational risk. It is questionable whether the literature can support the recommendations in their present form, and supposedly "cost-effective' solutions to the problem, pay scant regard to the fact that in risk management, the relative desirability of options is conditional on the alternatives considered, how they are framed, what evidence is consulted and how consequences are weighed. In informing the policy making process, it is imperative that the values of those whose voice is seldom heard, are considered.

Perinatal mortality in Northern Ireland: where are we now?

Perinatal mortality in Northern Ireland has been declining over the last 30 years, but the factors which may account for this fall have not been clearly delineated. Crude perinatal mortality figures yield very little insight into the problem, and meaningful management statistics are urgently required if service performance is to be reasonably assessed. This paper sets out the case for birth-weight standardisation and explores the utility of a broad diagnostic taxonomy of causes of death.