Complex differences in infection rates between ethnic groups in Scotland: a retrospective, national census-linked cohort study of 1.65 million cases.

BACKGROUND: Ethnicity can influence susceptibility to infection, as COVID-19 has shown. Few countries have systematically investigated ethnic variations in infection. METHODS: We linked the Scotland 2001 Census, including ethnic group, to national databases of hospitalizations/deaths and serological diagnoses of bloodborne viruses for 2001-2013. We calculated age-adjusted rate ratios (RRs) in 12 ethnic groups for all infections combined, 15 infection categories, and human immunodeficiency virus (HIV), hepatitis B (HBV) and hepatitis C (HCV) viruses. RESULTS: We analysed over 1.65 million infection-related hospitalisations/deaths. Compared with White Scottish, RRs for all infections combined were 0.8 or lower for Other White British, Other White and Chinese males and females, and 1.2-1.4 for Pakistani and African males and females. Adjustment for socioeconomic status or birthplace had little effect. RRs for specific infection categories followed similar patterns with striking exceptions. For HIV, RRs were 136 in African females and 14 in males; for HBV, 125 in Chinese females and 59 in males, 55 in African females and 24 in males; and for HCV, 2.3-3.1 in Pakistanis and Africans. CONCLUSIONS: Ethnic differences were found in overall rates and many infection categories, suggesting multiple causative pathways. We recommend census linkage as a powerful method for studying the disproportionate impact of COVID-19.

The challenge of using routinely collected data to compare hospital admission rates by ethnic group: a demonstration project in Scotland.

BACKGROUND: Recording patients' ethnic group supports efforts to achieve equity in health care provision. Before the Equality Act (2010), recording ethnic group at hospital admission was poor in Scotland but has improved subsequently. We describe the first analysis of the utility of such data nationally for monitoring ethnic variation. METHODS: We analysed all in-patient or day case hospital admissions in 2013. We imputed missing data using the most recent ethnic group recorded for a patient from 2009 to 2015. For episodes lacking an ethnic code, we attributed known ethnic codes proportionately. Using the 2011 Census population, we calculated rates and rate ratios for all-cause admissions and ischaemic heart diseases (IHDs) directly standardized for age. RESULTS: Imputation reduced missing ethnic group codes from 24 to 15% and proportionate redistribution to zero. While some rates for both all-cause and IHD admissions appeared plausible, unexpectedly low or high rates were observed for several ethnic groups particularly amongst White groups and newly coded groups. CONCLUSIONS: Completeness of ethnicity recoding on hospital admission records has improved markedly since 2010. However the validity of admission rates based on these data is variable across ethnic groups and further improvements are required to support monitoring of inequality.

Test, test, test for COVID-19 antibodies: the importance of sensitivity, specificity and predictive powers.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody tests of varying specificity and sensitivity are now available. For informing individuals whether they have had coronavirus disease 2019 (COVID-19), they need to be very accurate. For measuring population prevalence of past infection, the numbers of false positives and negatives need to be roughly equal. With a series of worked examples for a notional population of 100,000 people, we show that even test systems with a high specificity can yield a large number of false positive results, especially where the population prevalence is low. For example, at a true population prevalence of 5%, using a test with 99% sensitivity and specificity, 16% of positive results will be false and thus 950 people will be incorrectly informed they have had the infection. Further confirmatory testing may be needed. Giving false reassurance on which personal or societal decisions might be based could be harmful for individuals, undermine public confidence and foster further outbreaks.

Ethnic variations in falls and road traffic injuries resulting in hospitalisation or death in Scotland: the Scottish Health and Ethnicity Linkage Study.

OBJECTIVES: To investigate ethnic differences in falls and road traffic injuries (RTIs) in Scotland. STUDY DESIGN: A retrospective cohort of 4.62 million people, linking the Scottish Census 2001, with self-reported ethnicity, to hospitalisation and death records for 2001-2013. METHODS: We selected cases with International Classification of Diseases-10 diagnostic codes for falls and RTIs. Using Poisson regression, age-adjusted risk ratios (RRs, multiplied by 100 as percentages) and 95% confidence intervals (CIs) were calculated by sex for 10 ethnic groups with the White Scottish as reference. We further adjusted for country of birth and socio-economic status (SES). RESULTS: During about 49 million person-years, there were 275,995 hospitalisations or deaths from fall-related injuries and 43,875 from RTIs. Compared with the White Scottish, RRs for falls were higher in most White and Mixed groups, e.g., White Irish males (RR: 131; 95% CI: 122-140) and Mixed females (126; 112-143), but lower in Pakistani males (72; 64-81) and females (72; 63-82) and African females (79; 63-99). For RTIs, RRs were higher in other White British males (161; 147-176) and females (156; 138-176) and other White males (119; 104-137) and females (143; 121-169) and lower in Pakistani females (74; 57-98). The ethnic variations differed by road user type, with few cases among non-White motorcyclists and non-White female cyclists. The RRs were minimally altered by adjustment for country of birth or SES. CONCLUSION: We found important ethnic variations in injuries owing to falls and RTIs, with generally lower risks in non-White groups. Culturally related differences in behaviour offer the most plausible explanation, including variations in alcohol use. The findings do not point to the need for new interventions in Scotland at present. However, as the ethnic mix of each country is unique, other countries could benefit from similar data linkage-based research.

Differences in all-cause hospitalisation by ethnic group: a data linkage cohort study of 4.62 million people in Scotland, 2001-2013.

OBJECTIVES: Immigration into Europe has raised contrasting concerns about increased pressure on health services and equitable provision of health care to immigrants or ethnic minorities. Our objective was to find out if there were important differences in hospital use between the main ethnic groups in Scotland. STUDY DESIGN: A census-based data linkage cohort study. METHODS: We anonymously linked Scotland's Census 2001 records for 4.62 million people, including their ethnic group, to National Health Service general hospitalisation records for 2001-2013. We used Poisson regression to calculate hospitalisation rate ratios (RRs) in 14 ethnic groups, presented as percentages of the White Scottish reference group (RR = 100), for males and females separately. We adjusted for age and socio-economic status and compared those born in the United Kingdom or the Republic of Ireland (UK/RoI) with elsewhere. We calculated mean lengths of hospital stay. RESULTS: 9.79 million hospital admissions were analysed. Compared with the White Scottish, unadjusted RRs for both males and females in most groups were about 50-90, e.g. Chinese males 49 (95% confidence interval [CI] = 45-53) and Indian females 76 (95% CI 71-81). The exceptions were White Irish, males 120 (95% CI 117-124) and females 115 (95% CI 112-119) and Caribbean females, 103 (95% CI 85-126). Adjusting for age increased the RRs for most groups towards or above the reference. Socio-economic status had little effect. In many groups, those born outside the UK/RoI had lower admission rates. Unadjusted mean lengths of stay were substantially lower in most ethnic minorities. CONCLUSIONS: Use of hospital beds in Scotland by most ethnic minorities was lower than by the White Scottish majority, largely explained by their younger average age. Other countries should use similar methods to assess their own experience.

After 50 years and 200 papers, what can the Midspan cohort studies tell us about our mortality?

OBJECTIVE: To distil the main findings from published papers on mortality in three cohorts involving over 27,000 adults, recruited in Scotland between 1965 and 1976 and followed up ever since. METHOD: We read and summarized 48 peer-reviewed papers about all-cause and cause-specific mortality in these cohorts, published between 1978 and 2013. RESULTS: Mortality rates were substantially higher among cigarette smokers in all social classes and both genders. Exposure to second-hand smoke was also damaging. Exposure to higher levels of black smoke pollution was associated with higher mortality. After smoking, diminished lung function was the risk factor most strongly related to higher mortality, even among never-smokers. On average, female mortality rates were much lower than male but the same risk factors were predictors of mortality. Mortality rates were highest among men whose paternal, own first and most recent jobs were manual. Specific causes of death were associated with different life stages. Upward and downward social mobility conferred intermediate mortality rates. Low childhood cognitive ability was strongly associated with low social class in adulthood and higher mortality before age 65 years. There was no evidence that daily stress contributed to higher mortality among people in lower social positions. Men in manual occupations with fathers in manual occupations, who smoked and drank >14 units of alcohol a week had cardiovascular disease mortality rates 4.5 times higher than non-manual men with non-manual fathers, who neither smoked nor drank >14 units. Men who were obese and drank >14 units of alcohol per day had a mortality rate due to liver disease 19 times that of normal or underweight non-drinkers. Among women who never smoked, mortality rates were highest in severely obese women in the lowest occupational classes. CONCLUSION: These studies highlight the cumulative effect of adverse exposures throughout life, the complex interplay between social circumstances, culture and individual capabilities, and the damaging effects of smoking, air pollution, alcohol and obesity.

Smoke-free legislation: global reach, impact and remaining challenges.

Article 8 of the World Health Organization Framework Convention on Tobacco Control (2005) requires all signatory countries to adopt measures to protect people from tobacco smoke in indoor workplaces, indoor public places, public transport and other public places as appropriate. The aims of this symposium were to review progress across the world, to assess the evidence for the impact of legislation on health, and to identify the continuing challenges in making universal protection a reality. There was agreement that even in countries where strict legislation is enforced, many children continue to be dangerously exposed to parental second-hand smoke in the womb, the home and private cars. The importance of using accurate estimates of the burden of disease caused by second-hand smoke was agreed, in order to present an unassailable case for legislation and enforcement.

World Congress of Epidemiology 2011: themes and highlights.

Modern-day epidemiologists are confronted with huge changes, such as the rise in the global population due to reduced mortality, migration within and across countries, massive shifts in economic standing and lifestyles, and environmental degradation. With over 1000 posters, more than 100 oral presentations, 16 workshops, four lunchtime symposia, many exhibitions and immeasurable discussions, the task of capturing all highlights of the International Epidemiology Association (IEA) World Congress of Epidemiology 2011 is impossible, but this article has provided a sample. Many presenters showed that the challenges facing global health are complex, changing and in demand of measurement, and they demonstrated the central role of epidemiology. The cutting-edge methodologies theme promised the emergence of a more transparent, better balanced, but also more critical approach to dealing with bias. Preceding the United Nations high-level meeting on non-communicable diseases (New York, 19th-20th September 2011), the Congress's chronic diseases stream was especially timely. The neglected conditions theme illustrated inspiring work battling against apathy, inertia and ignorance; perhaps the special challenge of the 'neglected conditions epidemiologist'. Translating epidemiology's insights into effective policies and programmes to prevent diseases or reduce their impact is not easy. Speakers highlighted the common failure of epidemiologists to contribute actively to improving the health of the populations they serve, especially the poor and disadvantaged, but also provided many examples where they had done so. The 'other' theme ensured that important studies were not lost from the programme just because they did not fit easily into the specific themes. The studies focused on identified risk factors throughout the life course. A variety of methods were used to identify factors that altered the rate of birth, disease and death. Ongoing epidemiology is not only broad but is also deep, and ever more so as collaborative pooling of expertise, data, populations and ideas has emerged, accelerated by modern-day communication technologies. Epidemiology, and epidemiologists, seem poised for tomorrow's world.

Estimates of HIV infection among injecting drug users in Glasgow, 1985-1990.

OBJECTIVE: To use research and surveillance studies in Glasgow (Scotland, UK) to estimate the number of current injectors infected with HIV, the total number of injectors infected up to the end of 1990 and the recent incidence of infection. DESIGN: (A) Prevalence of injecting drug use was estimated using log-linear modelling. (B) Prevalence of HIV infection was determined from voluntary testing of a community-wide sample of injectors. (C) The number of infected current injectors was predicted by combining the distributions generated by (A) and (B). (D) Data on known HIV-positive injectors were used in conjunction with (C) to forecast the cumulative number of infected injectors. RESULTS: The number of current injectors was estimated to be 9400; the prevalence of HIV infection among 447 injectors recruited to the HIV prevalence study during 1990 was 1.1%. From these data, the number of HIV-positive current injectors in 1990 was estimated to be between 52 and 138. Between 1985 and 1990, 110 known HIV-positive injectors were registered or received treatment in Glasgow for HIV-related diseases; the total number of cases estimated to have occurred during this period was between 110 and 300. The incidence of infection in Glasgow during 1990 was likely to have been low in light of the finding that only one case in the prevalence study had not previously been diagnosed HIV-positive. CONCLUSIONS: Linkage of datasets from a variety of sources and studies has enabled the substantial refinement of estimates of the number of injectors and the proportion infected with HIV in Glasgow up to 1990.

Disinfection of hands and tubing of CAPD patients.

During a 3 month study the effectiveness of two methods of handwashing was assessed in a group of 31 patients undergoing continuous ambulatory peritoneal dialysis. A defined, double rinse with alcohol, prior to bag exchange, was found to be more convenient and significantly more effective than povidone-iodine alone or povidone-iodine followed by alcohol. Spraying the tubing around the bag connector with 70 per cent ethanol reduced the numbers of adherent skin organisms so reducing the likelihood of bacteria being drawn into the dialysate. Although there was no difference in the overall incidence of peritonitis in the two groups of patients studied, there was an unexpected drop in the incidence of peritonitis caused by coagulase-negative skin staphylococci. This was attributed to an overall awareness of the importance of handwashing and aseptic procedures during bag exchange. Monitoring the bacteriology of the catheter exit site may give some prior indication as to the likelihood of subsequent peritonitis especially with Staphylococcus aureus and Gram-negative bacilli.

Injecting-related harm and treatment-seeking behaviour among injecting drug users.

AIMS: This study aims to identify the physical harm associated with injecting drug use and examine the treatment-seeking behaviour of injecting drug users (IDUs). Specific attention is given to the factors associated with presentation and non-presentation of injecting-related problems. DESIGN: Participants were interviewed by research staff using a semi-structured questionnaire, then physically examined by a medical team. SETTING: Needles exchanges in Glasgow. PARTICIPANTS: One hundred and twelve injecting drug users. FINDINGS: Respondents' accounts of their current injecting-related problems were found to be consistent with the clinician's findings, suggesting that IDUs are able to self-diagnose injecting-related harm. However, almost three-quarters had not sought help for these problems. Qualitative data suggest the main reasons for non-presentation, or delayed presentation, of injecting-related problems are normalization of injecting-related harm and a reluctance to attend available services. Almost half of those seeking treatment for injecting-related problems did so during an emergency or crisis. CONCLUSIONS: Low threshold services, such as needle exchanges, may have to take a more proactive stance to encourage injectors to present with injecting-related problems. This may help reduce injecting-related harms, especially the resulting medical complications, which would in turn relieve the pressure on other services such as hospital Accident and Emergency Departments.

Factors associated with injecting risk behaviour among serial community-wide samples of injecting drug users in Glasgow 1990-94: implications for control and prevention of blood-borne viruses.

AIMS: To examine the association between recipient-sharing of needles and syringes and demographic characteristics, injecting behaviour and needle and syringe exchange utilisation. DESIGN: Self-report data from serial cross-sectional surveys. SETTING: Multiple street, needle and syringe exchange and drug treatment sites throughout Glasgow. PARTICIPANTS: 2576 current injecting drug users (IDUs) recruited during 1990-94. FINDINGS: In the multiple logistic regression analysis, a significantly lower level of recipient-sharing was associated with respondents who resided within 1 mile of a needle and syringe exchange compared to those who lived further away (adjusted OR 1.3; 95% CI 1.0-1.6), and by IDUs who reported obtaining either 6-15, 16-30, or > 30 sterile needles and syringes in an average week from a needle exchange and/or pharmacist (adjusted ORs 0.55, 0.34, 0.25; 95% CIs 0.3-0.9, 0.2-0.6 and 0.2-0.4, respectively) compared to those who obtained no sterile equipment from these sources. Recipient-sharing of needles and syringes in the previous 6 months reduced significantly between 1990 (43%) and 1991-94 (27-33%) (p < 0.0001); this decline was not explained by needle and syringe exchange utilization, suggesting that additional factors were influencing behavioural change at that time. CONCLUSION: Our data indicate that improving injectors' convenience of access to exchange facilities and increasing the numbers of sterile needles and syringes available to them is likely to result in further reductions in recipient-sharing, and thus the potential for blood-borne virus transmission, among IDUs.

One-year follow-up of opiate injectors treated with oral methadone in a GP-centred programme.

AIMS: To examine changes in drug-related behaviour in opiate-dependent injectors treated with oral methadone, in a shared care scheme where consumption of the daily dose is usually supervised by a community pharmacist. DESIGN: One-year cohort study. SETTING: Recruitment from the main routes into methadone prescribing in Glasgow during 1996: General Practitioner Drug Misuse Clinic Scheme and the Drug Problem Service. PARTICIPANTS: Current opiate injectors entering methadone treatment. FINDINGS: Among the 204 injectors recruited, 148 (73%) were re-interviewed at 6 months and 118 (58%) at both 6 and 12 months. Twenty-nine per cent of the cohort remained continuously on methadone for 12 months. In that group, over the 12-month period, self-reported daily opiate injecting reduced from 78% to 2%; overdose in the previous 6 months from 24% to 2%; mean daily drug spend from 50 Pounds to 4 Pounds; and mean monthly number of acquisitive crimes reduced from 13 to three. Assuming participants lost to follow-up were unchanged, significant improvements in the total cohort were seen in daily opiate injecting (from 80% at recruitment to 43% at 12 months), overdose (from 27% to 15%), mean daily drug spend (from 63 Pounds to 38 Pounds) and mean monthly number of acquisitive crimes (from 18 to 11). Discontinuation of treatment was mainly due to imprisonment (39%) or sanctions by the prescriber (33%). CONCLUSION: Treatment of opiate-dependent drug injectors with methadone in a community-wide general practitioner-centred scheme, with supervised daily consumption, was associated with major beneficial change for a substantial proportion of patients.

Sexual behaviour and use of the condom by men attending gay bars and clubs in Glasgow and Edinburgh.

How widespread are the safer forms of sexual behaviour reportedly adopted by male homosexuals in recent years? A questionnaire was completed by 173 and 83 gay men attending gay bars and clubs in Edinburgh and Glasgow respectively. Comparisons were made between those who reported using the condom (n = 137, [54%]) and those who did not (n = 119, [46%]). Sixty percent of respondents reported more than 5 partners during the previous year. Condom use was much less common among men with less than 5 years' experience as a practising homosexual. Less than one-fifth of respondents reported always using a condom during anal intercourse. Orogenital contact without a condom was reported by 84% of all respondents, and unprotected anal intercourse by 40%, (over 30% for those who used condoms). About one-third of condom users but only 14% of non-users thought they were at risk of catching HIV because of their sexual behaviour, although 80% of users and 70% of non-users said their lifestyles had been affected by the HIV epidemic. While there were some encouraging signs of behaviour change, unprotected anal sex is still widely practised. Gay bars and clubs represent important venues for conveying the safer sex message.

PIP: Completed questionnaires were received from 173 and 83 gay men attending gay bars and clubs in Edinburgh and Glasgow, respectively, in a study of respondents' sexual behavior and condom use. The questionnaire response rate in Glasgow was half that achieved in Edinburgh. Respondents were of mean age 28 years who had had sex with men in the past year. 21% also reported having at least one female sex partner during that period. 60% reported having more than five sex partners during the previous year. 137 reported using condoms and 119 reported not using them. Condom use was relatively less common among men with less than five years experience as a practicing homosexual. Less than 20% of respondents reported always using a condom during anal intercourse. Orogenital contact without a condom was reported by 84% of all respondents and unprotected anal intercourse by 40%. 31% of condom users and 14% of non-users thought they were at risk of contracting HIV because of their sexual behavior, but 80% of users and 70% of non-users said their lifestyles had been affected by the HIV epidemic. The authors note on the basis of these findings that unprotected anal sexual intercourse remains widely practiced despite some encouraging signs of behavior change. As such, gay bars and clubs are important venues in which safer sex messages could be conveyed.

A lasting public health response to an outbreak of HIV infection in a Scottish prison?

Between April and June 1993, 8 cases of acute clinical hepatitis B infection and 2 seroconversions to HIV infection were detected among drug injecting inmates of HM Prison Glenochil in Scotland. To prevent the further spread of infection, an initiative which involved counselling and voluntary attributable HIV testing was conducted over a 10-day period commencing at the end of June. A team of 18 counsellors and phlebotomists was brought together rapidly as part of a unique organizational exercise in the field of public health. Fourteen cases of HIV infection were identified of which 13 were almost certainly infected in Glenochil. Following the exercise, a range of harm reduction measures for injecting prisoners was introduced; these included the availability of hepatitis B vaccine, provision of bleach tablets which could be used to clean injecting equipment, a methadone detoxification programme, increased training for prison officers and improved access to drug and harm minimization counselling for inmates. By mid-1996 all these measures had been sustained and several could be found in many other prisons throughout Scotland. Follow-up investigations showed no evidence of epidemic spread of HIV during the 12 months after the initiative. While the frequency of injecting and needle/syringe sharing may have decreased over the last 3 years, these activities are still being reported and it is highly likely that transmissions of bloodborne infections, in particular hepatitis C, continue to occur. The surveillance and prevention of infections associated with injecting drug use in the prison setting remain a high public health priority.

Distribution of HIV and acute hepatitis B infection among drug injectors in Glasgow.

This study compared the distributions of known human immunodeficiency virus (HIV) and acute hepatitis B virus (HBV) infection among drug injectors in Glasgow over a 3.5 year period. Data were obtained from all relevant laboratory request forms submitted to Glasgow's 3 virology laboratories during the period 1 January 1986 to 30 June 1989. The overall prevalence of HIV among those tested was 3.7% (66/1786). There were 125 cases of acute HBV infection. The male:female ratios for HIV and acute HBV were 1:1 and 2:1, respectively. Thirty-four per cent of persons with HIV were aged under 21 years compared with 53% with acute HBV. Three out of 10 areas of the city accounted for 92% of HIV infection but only 66% of acute HBV infection. HIV infection was not detected among drug injectors in 4 areas of the city but at least 2 cases of acute HBV infection were recorded in all 10 areas. The geographical and age distribution of acute HBV infection in Glasgow suggests that the potential for future spread of HIV among drug injectors remains considerable.

Low and stable prevalence of HIV among drug injectors in Glasgow.

The first HIV-positive diagnosis among injecting drug users (IDU) in Glasgow was made in 1985. By the end of 1987 prevalence among IDU receiving voluntary attributable tests was 4.8%. Since 1990, an annual cross-sectional survey of HIV prevalence and risk behaviours among 500 current Glasgow IDU has provided a more representative sample. Anonymously-tested saliva samples obtained from respondents revealed prevalence rates of 1.8%, 1.2% and 1.0% in 1990, 1991 and 1992 respectively. Since 1987 a wide range of measures aimed at reducing HIV-related risk behaviour among IDU has been introduced and maintained in Glasgow. Against this background, there is evidence that IDU in the city have reduced their risk behaviours. The findings reported here suggest that implementing harm-reduction measures when prevalence is low may inhibit the rapid dissemination of HIV.

Building a city wide service for exchanging needles and syringes.

How best can injecting drug misusers obtain clean injecting equipment in a city where drug injecting is widespread? An exchange service for needles and syringes throughout Glasgow has been established in health centres and clinics in the evening. Over the past four years seven new exchanges have been opened and over 2700 injecting drug misusers have attended. Attendances rose from under 1000 in 1988 to 28,000 in 1992. The exchanges also provide a wide range of other health and social services. Public hostility to the exchanges has abated. During the same period equipment sharing in the city diminished and the observed prevalence of HIV among injecting drug misusers stabilised at around 1%.