Ellen J. Amundsen

Mortality among drug users after discharge from inpatient treatment: An 8-year prospective study

BACKGROUND Drug users who are leaving/completing inpatient medication-free treatment may, like drug users released from prison, have an elevated risk of dying from fatal overdoses. This is mainly explained by their low drug tolerance. METHODS Two hundred and seventy-six drug users who had been admitted to 11 inpatient facilities in Norway, were followed prospectively after discharge from treatment during an 8-year period (1998-2006). The following instruments were used: EuropASI, SCL-25 and MCMI II. Information on deaths and causes of death were obtained from the National Death Register. RESULTS A total of 36 deaths were registered after discharge from treatment during the observation period, of which 24 were classified as overdose deaths. During the first 4 weeks after discharge six persons died, yielding an unadjusted excess mortality of 15.7 (rate ratio) in this period (CI 5.3-38.3). All were dropouts and all deaths were classified as opiate overdoses. There was no significant association between time in index treatment and mortality after discharge, nor did any background characteristics correlate significantly with elevated mortality shortly after discharge. CONCLUSIONS The elevated risk of dying from overdose within the first 4 weeks of leaving medication-free inpatient treatment is so dramatic that preventive measures should be taken. More studies from similar inpatient programmes are needed in order to obtain systematic knowledge about determinants of overdose deaths shortly after leaving treatment, and possible preventive measures.

All-cause and liver-related mortality in hepatitis C infected drug users followed for 33 years: a controlled study.

BACKGROUND & AIMS The course of chronic hepatitis C virus (HCV) in injecting drug users (IDUs) has not been well described. The aim of this study was to compare long-term all-cause and liver-related mortality among anti-HCV positive IDUs with and without persisting HCV infection. METHODS A retrospective-prospective controlled cohort design was applied. All IDUs admitted to resident drug treatment (1970-1984) and with available stored sera were screened for anti-HCV antibody. Anti-HCV positive individuals were further tested for the presence of HCV RNA. All-cause and liver-related mortality was compared between HCV RNA positive (n=328) and HCV RNA negative individuals (n=195). The observation was accomplished through register linkage to national registers. Mean observation time was 33 years. RESULTS All-cause mortality rate was 1.85 (95% CI 1.62-2.11) per 100 person-years, male 2.11 (95% CI 1.84-2.46), female 1.39 (95% CI 1.07-1.79). Mortality rates were not influenced by persisting HCV infection. Main causes of death were intoxications (45.0%), suicide (9.1%), and accidents (8.2%). Liver disease was the cause of death in 7.5% of deaths among HCV RNA positive subjects. Five of 13 deaths among male IDUs with persisting HCV infection occurring after the age of 50 years were caused by liver disease. CONCLUSIONS The all-cause mortality in IDUs is high and with no difference between HCV RNA positive and HCV RNA negative individuals, the first three decades after HCV transmission. However, among IDUs with chronic HCV infection who have survived until 50years of age, HCV infection emerges as the main cause of death.

Low level of alcohol drinking among two generations of non-Western immigrants in Oslo: a multi-ethnic comparison.

BackgroundAlcohol drinking is a risk factor for harm and disease. A low level of drinking among non-Western immigrants may lead to less alcohol-related harm and disease. The first aim of this study was to describe frequency of drinking in two generations of immigrants in Oslo, contrasting the result to drinking frequency among ethnic Norwegians. The second aim was to study how frequency of drinking among adult immigrants was associated with social interaction with their own countrymen and ethnic Norwegians, acculturation, age, gender, socioeconomic factors and the Muslim faith.MethodThe Oslo Health Study (HUBRO) was conducted during the period 2000 to 2002 and consisted of three separate surveys: a youth study (15-16-year-olds, a total of 7343 respondents, response rate 88.3%); adult cohorts from 30 to 75 years old (18,770 respondents, response rate 46%); the five largest immigrant groups in Oslo (aged 20–60 years, a total of 3019 respondents, response rate 39.7%). Based on these three surveys, studies of frequency of drinking in the previous year (four categories) were conducted among 15-16-year-olds and their parents’ generation, 30-60-year-old Iranians, Pakistanis, Turks and ethnic Norwegians. A structural equation model with drinking frequency as outcome was established for the adult immigrants.ResultsAdults and youth of ethnic Norwegian background reported more frequent alcohol use than immigrants with backgrounds from Iran, Turkey and Pakistan. Iranians reported a higher drinking frequency than Turks and Pakistanis. In the structural equation model high drinking frequency was associated with high host culture competence and social interaction, while high own culture competence was associated with low drinking frequency. Adult first-generation immigrants with a longer stay in Norway, those of a higher age, and females drank alcohol less frequently, while those with a higher level of education and work participation drank more frequently. Muslim immigrants reported a significantly lower drinking frequency than non-Muslims, although this did not apply to Iranians.ConclusionsThe existence and growth in Western societies of immigrant groups with low-level alcohol consumption contributed to a lower level of consumption at the population level. This may imply reduced drinking and alcohol-related harm and disease even among ethnic Norwegians.

Definition and estimation of an actual reproduction number describing past infectious disease transmission: application to HIV epidemics among homosexual men in Denmark, Norway and Sweden

Prevalence and incidence measures are the common way to describe epidemics. The reproduction number supplies information on the potential for growth or decline of an epidemic. We define an actual reproduction number for infectious disease transmission that has taken place. An estimator is suggested, based on the number of new infections observed in a given time-interval, the number of those infected at the start of the interval, and the length of the infectious period. That estimator is applied to HIV among men having sex with other men over the period, 1977-1995, in Scandinavia. The actual reproduction number was estimated with acceptable certainty from the period, 1981-1982, yielding a value of 15 secondary cases. A value of less than one secondary case was assessed for the period, 1988-1995, in Denmark and Sweden. The actual reproduction number gives us some additional understanding of the dynamics of epidemics, compared with prevalence and incidence curves.

Estimation of cocaine consumption in the community: a critical comparison of the results from three complimentary techniques

Objectives A range of approaches are now available to estimate the level of drug use in the community so it is desirable to critically compare results from the differing techniques. This paper presents a comparison of the results from three methods for estimating the level of cocaine use in the general population. Design The comparison applies to; a set of regional-scale sample survey questionnaires, a representative sample survey on drug use among drivers and an analysis of the quantity of cocaine-related metabolites in sewage. Setting 14 438 participants provided data for the set of regional-scale sample survey questionnaires; 2341 drivers provided oral-fluid samples and untreated sewage from 570 000 people was analysed for biomarkers of cocaine use. All data were collected in Oslo, Norway. Results 0.70 (0.36–1.03) % of drivers tested positive for cocaine use which suggest a prevalence that is higher than the 0.22 (0.13–0.30) % (per day) figure derived from regional-scale survey questionnaires, but the degree to which cocaine consumption in the driver population follows the general population is an unanswered question. Despite the comparatively low-prevalence figure the survey questionnaires did provide estimates of the volume of consumption that are comparable with the amount of cocaine-related metabolites in sewage. Per-user consumption estimates are however highlighted as a significant source of uncertainty as little or no data on the quantities consumed by individuals are available, and much of the existing data are contradictory. Conclusions The comparison carried out in the present study can provide an excellent means of checking the quality and accuracy of the three measurement techniques because they each approach the problem from a different viewpoint. Together the three complimentary techniques provide a well-balanced assessment of the drug-use situation in a given community and identify areas where more research is needed.

Growth rates in epidemic models: Application to a model for HIV/AIDS progression

The most common quantity used to describe the growth of an epidemic when modelling infectious diseases is the basic reproduction number R0. While R0 is most appropriate for epidemics with short-lasting infections, long-lasting infections such as HIV/AIDS may call for the use of growth rates with other properties. For a group of multi-state compartment models we define both R0, the actual reproduction number Ra(t), and the intrinsic growth rate r. We study the relationship between these different reproduction numbers and growth rates and take a brief look at how they could be estimated from actual observed data. The work is illustrated by a model for HIV/AIDS progression among homosexual men in England and Wales. We conclude that other measures of growth, in addition to R0, give important supplementary information.

Liver fibrosis progression at autopsy in injecting drug users infected by hepatitis C: A longitudinal long-term cohort study

BACKGROUND & AIMS There is a paucity of unbiased data on the natural history of hepatitis C virus (HCV) infection in injecting drug users (IDUs). The purpose of this study was to assess the risk of developing advanced fibrosis associated with chronic hepatitis C (CHC) infection among injecting drug users (IDUs) who underwent an autopsy. METHODS A longitudinal cohort design was applied, in which the stage of liver fibrosis in anti-HCV positive IDUs with or without chronic HCV infection was assessed in liver tissue from autopsies performed up to 35 years after HCV exposure. The cohort originated from 864 IDUs consecutively admitted for drug abuse treatment 1970-1984. Stored sera, mostly drawn at the time of admission for drug treatment, were available in 635 subjects. 220 out of 523 anti-HCV positive subjects had died before 2009. Liver tissue from autopsies was available from 102/220 subjects, of which 61 were HCV RNA positive. Liver sections were classified according to METAVIR scores for fibrosis. Two pathologists, both blinded for serologic results, scored sections of liver tissue. RESULTS Among HCV RNA positive subjects 16.4% (10/61) had septal fibrosis (F3) or cirrhosis (F4) compared to 2.4% (1/41) among anti HCV positive/HCV RNA negative subjects (p=0.026). Of 18 HCV RNA positive subjects autopsied <15 years after HCV exposure none had F3 or F4. Among subjects autopsied >25 years after exposure 35% (6/17) had F3-F4. CONCLUSIONS Among IDUs chronically infected by HCV, 1/3 developed septal fibrosis or cirrhosis 25 years or more after exposure.

The contribution of imprisonment and release to fatal overdose among a cohort of Norwegian drug abusers

This study was designed to supplement knowledge of three aspects of fatal overdose and imprisonment. Our aims were to investigate whether drug abusers are subject to a higher-than-usual risk of fatal overdose immediately after release from prison, to assess the length of the high-risk period and to investigate the net effect of imprisonment–the pooled effect of both imprisonment and release–on overdose death. The analyses were conducted on the basis of data from a cohort of 338 imprisoned Norwegian drug abusers. Cox regression models were applied including the explanatory time-dependent covariate for imprisonment and the post-release period. We find that the risk of death from overdose during the 2 weeks after release from prison was 10 times higher, and during the 3-week period six times higher, than during other time spent outside prison. An elevated risk was also indicated for the fourth week. Taking into account findings in the literature, the period of elevated risk should be considered to last up to 4 weeks. When the risk period analysed includes both time spent in prison and the post-release period, the risk of fatal overdose is not found to differ from other periods outside prison.

Changes in mortality due to major alcohol‐related diseases in four Nordic countries, France and Germany between 1980 and 2009: a comparative age–period–cohort analysis

AIMS To investigate age, period and cohort effects on time trends of alcohol-related mortality in countries with different drinking habits and alcohol policies. DESIGN AND SETTING Age-period-cohort (APC) analyses on alcohol-related mortality were conducted in Denmark, Finland, Norway, Sweden, France and Germany. PARTICIPANTS Cases included alcohol-related deaths in the age range 20-84 years between 1980 and 2009. MEASUREMENTS Mortality data were taken from national causes of death registries and covered the ICD codes alcoholic psychosis, alcohol use disorders, alcoholic liver disease and toxic effect of alcohol. FINDINGS In all countries changes across age, period and cohort were found to be significant for both genders [effect value with confidence interval (CI) shown in Supporting information, Table S1]. Period effects pointed to an increase in alcohol-related mortality in Denmark, Finland and Germany and a slightly decreasing trend in Sweden, while in Norway an inverse U-shaped curve and in France a U-shaped curve was found. Compared with the cohorts born before 1960, the risk of alcohol-related mortality declined substantially in cohorts born in the 1960s and later. Pairwise between-country comparisons revealed more statistically significant differences for period (P < 0.001 for all 15 comparisons by gender) than for age [P < 0.001 in seven (men) and four (women) of 15 comparisons] or cohort [P < 0.01 in two (men) and three (women) of 15 comparisons]. CONCLUSIONS Strong period effects suggest that temporal changes in alcohol-related mortality in Denmark, Finland, Norway, Sweden, France and Germany between 1980 and 2009 were related to secular differences affecting the whole population and that these effects differed across countries.

Changes in mortality due to major alcohol-related diseases in four Nordic countries, France and Germany between 1980 and 2009: a comparative age-period-cohort analysis

AIMS To investigate age, period and cohort effects on time trends of alcohol-related mortality in countries with different drinking habits and alcohol policies. DESIGN AND SETTING Age-period-cohort (APC) analyses on alcohol-related mortality were conducted in Denmark, Finland, Norway, Sweden, France and Germany. PARTICIPANTS Cases included alcohol-related deaths in the age range 20-84 years between 1980 and 2009. MEASUREMENTS Mortality data were taken from national causes of death registries and covered the ICD codes alcoholic psychosis, alcohol use disorders, alcoholic liver disease and toxic effect of alcohol. FINDINGS In all countries changes across age, period and cohort were found to be significant for both genders [effect value with confidence interval (CI) shown in Supporting information, Table S1]. Period effects pointed to an increase in alcohol-related mortality in Denmark, Finland and Germany and a slightly decreasing trend in Sweden, while in Norway an inverse U-shaped curve and in France a U-shaped curve was found. Compared with the cohorts born before 1960, the risk of alcohol-related mortality declined substantially in cohorts born in the 1960s and later. Pairwise between-country comparisons revealed more statistically significant differences for period (P < 0.001 for all 15 comparisons by gender) than for age [P < 0.001 in seven (men) and four (women) of 15 comparisons] or cohort [P < 0.01 in two (men) and three (women) of 15 comparisons]. CONCLUSIONS Strong period effects suggest that temporal changes in alcohol-related mortality in Denmark, Finland, Norway, Sweden, France and Germany between 1980 and 2009 were related to secular differences affecting the whole population and that these effects differed across countries.