Fanny Janssen

ICD coding changes and discontinuities in trends in cause-specific mortality in six European countries, 1950-99

OBJECTIVE To evaluate how often coding changes between and within revisions of the International Classification of Diseases (ICD) complicate the description of long-term trends in cause-specific mortality. METHODS Data on cause-specific mortality between 1950 and 1999 for men and women aged 60 and older were obtained from Denmark, England and Wales, Finland, the Netherlands, Norway and Sweden. Data were obtained by five-year age groups. We constructed a concordance table using three-digit ICD codes. In addition we evaluated the occurrence of mortality discontinuities by visually inspecting cause-specific trends and country-specific background information. Evaluation was also based on quantification of the discontinuities using a Poisson regression model (including period splines). We compared the observed trends in cause-specific mortality with the trends after adjustment for the discontinuities caused by changes to coding. FINDINGS In 45 out of 416 (10.8 %) instances of ICD revisions to cause-specific mortality codes, significant discontinuities that were regarded as being due to ICD revisions remained. The revisions from ICD-6 and ICD-7 to ICD-8 and a wide range of causes of death, with the exception of the specific cancers, were especially affected. Incidental changes in coding rules were also important causes of discontinuities in trends in cause-specific mortality, especially in England and Wales, Finland and Sweden. Adjusting for these discontinuities can lead to significant changes in trends, although these primarily affect only limited periods of time. CONCLUSION Despite using a carefully constructed concordance table based on three-digit ICD codes, mortality discontinuities arising as a result of coding changes (both between and within revisions) can lead to substantial changes in long-term trends in cause-specific mortality. Coding changes should therefore be evaluated by researchers and, where necessary, controlled for.

The Decline in Stroke Mortality: Exploration of Future Trends in 7 Western European Countries

Background and Purpose— This article aims to make projections of future trends in stroke mortality in the Year 2030 based on recent trends in stroke mortality in 7 Western European countries. Methods— Mortality data were obtained from national cause of death registries. Annual rates of decline in stroke mortality of 1980 to 2005 were determined for men and women in the United Kingdom, France, the Netherlands, and 4 Nordic countries on the basis of regression analysis. Estimated rates of decline were extrapolated until 2030. Cause-elimination life tables were used to determine the effect of stroke in 2030 in terms of potential gain in life expectancy. The absolute numbers of stroke deaths in 2030 were estimated using national population projections of Eurostat. Results— In all countries, stroke mortality rates declined incessantly until 2005 among both men and women. If these trends were to continue, age-adjusted mortality rates would decline by approximately half between 2005 and 2030 with larger declines in France (approximately two thirds) and smaller declines in the Netherlands, Denmark, and Sweden (approximately one fourth). Similar rates of decline would be observed in terms of potential gain in life expectancy. Because of population aging, the absolute number of stroke deaths would decline slowly in the United Kingdom and France and stabilize or even increase in other countries. Conclusions— In the near future, stroke may lose much of its effects on life expectancy but remain a frequent cause of death among elderly populations. The prevention of stroke-related disability instead of mortality may become increasingly more important.

The choice among past trends as a basis for the prediction of future trends in old-age mortality

We explored the extent to which projections of future old-age mortality trends differ when different projection bases are used. For seven European countries, four alternative sets of annual rates of mortality change were estimated with age–period log-linear regression models, and subsequently applied to age-specific all-cause mortality rates (80+) in 1999 to predict mortality levels up to 2050. On average, up to 2050, e80 is predicted to increase further by 2.33 years among men and 4.03 years among women. Choosing a historical period of 25 instead of 50 years results in higher predicted gains in e80 for men but lower gains for women. Choosing non-smoking-related mortality instead of all-cause mortality leads to higher gains for women and mixed results for men. In all alternatives there is a strong divergence of predicted mortality levels between the countries. Future projections should be preceded by a thorough study of past trends and their determinants.

Including the Smoking Epidemic in Internationally Coherent Mortality Projections

We present a new mortality projection methodology that distinguishes smoking- and non-smoking-related mortality and takes into account mortality trends of the opposite sex and in other countries. We evaluate to what extent future projections of life expectancy at birth (e0) for the Netherlands up to 2040 are affected by the application of these components. All-cause mortality and non-smoking-related mortality for the years 1970–2006 are projected by the Lee-Carter and Li-Lee methodologies. Smoking-related mortality is projected according to assumptions on future smoking-attributable mortality. Projecting all-cause mortality in the Netherlands, using the Lee-Carter model, leads to high gains in e0 (4.1 for males; 4.4 for females) and divergence between the sexes. Coherent projections, which include the mortality experience of the other 21 sex- and country-specific populations, result in much higher gains for males (6.4) and females (5.7), and convergence. The separate projection of smoking and non-smoking-related mortality produces a steady increase in e0 for males (4.8) and a nonlinear trend for females, with lower gains in e0 in the short run, resulting in temporary sex convergence. The latter effect is also found in coherent projections. Our methodology provides more robust projections, especially thanks to the distinction between smoking- and non-smoking-related mortality.

The decline in stomach cancer mortality: exploration of future trends in seven European countries

Mortality from stomach cancer has fallen steadily during the past decades. The aim of this paper is to assess the implication of a possible continuation of the decline in stomach cancer mortality until the year 2030. Annual rates of decline in stomach cancer mortality from 1980 to 2005 were determined for the Netherlands, United Kingdom, France, and four Nordic countries on the basis of regression analysis. Mortality rates were extrapolated until 2030, assuming the same rate of decline as in the past, using three possible scenarios. The absolute numbers of deaths were projected taking into account data on the ageing of national populations. Stomach cancer mortality rates declined between 1980 and 2005 at about the same rate (3.6–4.9% per year) for both men and women in all countries. The rate of decline did not level off in recent years, and it was not smaller in countries with lower overall mortality rates in 1980. If this decline were to continue into the future, stomach cancer mortality rates would decline with about 66% between 2005 and 2030 in most populations, while the absolute number of stomach cancer deaths would diminish by about 50%. Thus, in view of the strong, stable and consistent mortality declines in recent decades, and despite population ageing, stomach cancer is likely to become far less important as a cause of death in Europe in the future.

Relation between trends in late middle age mortality and trends in old age mortality : is there evidence for mortality selection?

Study objective: To test whether mortality selection was a dominant factor in determining trends in old age mortality, by empirically studying the existence of a negative correlation between trends in late middle age mortality and trends in old age mortality among the same cohorts. Design and methods: A cohort approach was applied to period data on total and cause specific mortality for Denmark, England and Wales, Finland, France, the Netherlands, Norway, and Sweden, in 1950–1999. The study described and correlated mortality trends for five year centralised cohorts from 1895 to 1910 at ages 55–69, with the trends for the same cohorts at ages 80–89. The research distinguished between circulatory diseases, cancers, and diseases specifically related to old age. Main results: All cause mortality changes at ages 80–89 were strongly positively correlated with all cause mortality changes at ages 55–69, especially among men, and in all countries. Virtually the same correlations were seen between all cause mortality changes at ages 80–89 and changes in circulatory disease mortality at ages 55–69. Trends in mortality at ages 80–89 from infectious diseases, pneumonia, diabetes mellitus, symptoms, or external causes showed no clear negative correlations with all cause mortality trends at ages 55–69. Conclusions: The consistently positive correlations seen in this study suggest that trends in old age mortality in north western Europe in the late 20th century were determined predominantly by the prolonged effects of exposures carried throughout life, and not by mortality selection.

The decline in ischaemic heart disease mortality in seven European countries: exploration of future trends

Background To assess the implication of a possible continuation of the decline in ischaemic heart disease (IHD) mortality in the future. Methods Annual rates of decline in IHD mortality from 1980–2005 were determined for the national populations of the Netherlands, UK, France and four Nordic countries through regression analysis and used to extrapolate mortality rates until 2030. Through cause-elimination life tables we determined the impact of IHD on life expectancy at birth. Results In all countries, IHD mortality rates among both sexes declined incessantly until 2005. Age-adjusted mortality rates would have declined by about 50% in 2030 compared to 2005 if past trends were to continue. The impact of IHD on life expectancy at birth would decline by about 25–50% in most populations. The absolute numbers of IHD deaths would decline slowly or even increase in some countries mainly because of population ageing. Conclusions If current IHD mortality trends continued, IHD would lose much of its importance as a cause of premature death in the near future. As the incidence and disabling impact of IHD might decline much less, prevention of IHD-related disability instead of mortality may become increasingly important in the future.

Systematic review of public health research on prevention of mother-to-child transmission of HIV in India with focus on provision and utilization of cascade of PMTCT services

BackgroundIn spite of effective strategies to eliminate mother-to-child-transmission of HIV, the implementation of such strategies remains a major challenge in developing countries. In India, programs for the prevention of mother-to-child transmission (PMTCT) have been scaled up widely since 2005. However, these programs reach only a small percentage of pregnant women, and their overall effectiveness is low. Evidence-based program planning and implementation could significantly improve their effectiveness. This study sought to systematically retrieve, thematically categorize and review published research on PMTCT of HIV in India, focusing on research related to the provision and/or utilization of the cascade of services provided in a PMTCT program, in order to direct further research to enhance program implementation and effectiveness.MethodsA systematic search using MEDLINE, US National Library of Medicine Gateway system (PubMed) and ISI Web of Knowledge resulted in 1,944 abstracts, of which 167 met our inclusion criteria.ResultsA huge share of the empirical literature on PMTCT in India (N = 134) deals with epidemiological studies (N = 60). The 46 papers related to utilization/provision of the cascade of PMTCT services were mostly from the four high HIV prevalence states in southern India and from the public sector. Studies on experiences of implementing a PMTCT program (N = 20) show high rates of drop out of women in the cascade particularly prior to receiving ARV. Studies on individual components of the cascade (N = 26) show that HIV counseling and testing is acceptable and feasible. Literature on other components of the cascade - such as pregnant women’s access to ANC care, HIV infected women’s immunological assessment using CD4 testing, repeat HIV testing among pregnant women, early infant diagnosis and factors related to linking HIV infected women and children to postnatal care – is lacking.ConclusionsWhile the scale of the Indian PMTCT program is large, comprehensive understanding of the context-driven factors affecting its efficiency is lacking. Systematic and more focused public health research output is needed on the issues related to reduction of drop outs of women in the cascade, role of PMTCT programs in improving maternal and child health indicators and role of private sector in delivering PMTCT services.

Estimating time-varying drug adherence using electronic records : extending the proportion of days covered (PDC) method

Accurate measurement of drug adherence is essential for valid risk‐benefit assessments of pharmacologic interventions. To date, measures of drug adherence have almost exclusively been applied for a fixed‐time interval and without considering changes over time. However, patients with irregular dosing behaviour commonly have a different prognosis than patients with stable dosing behaviour.

Using spatial analysis to predict health care use at the local level: a case study of type 2 diabetes medication use and its association with demographic change and socioeconomic status.

Local health status and health care use may be negatively influenced by low local socio-economic profile, population decline and population ageing. To support the need for targeted local health care, we explored spatial patterns of type 2 diabetes mellitus (T2DM) drug use at local level and determined its association with local demographic, socio-economic and access to care variables. We assessed spatial variability in these associations. We estimated the five-year prevalence of T2DM drug use (2005–2009) in persons aged 45 years and older at four-digit postal code level using the University of Groningen pharmacy database IADB.nl. Statistics Netherlands supplied data on potential predictor variables. We assessed spatial clustering, correlations and estimated a multiple linear regression model and a geographically weighted regression (GWR) model. Prevalence of T2DM medicine use ranged from 2.0% to 25.4%. The regression model included the extent of population ageing, proportion of social welfare/benefits, proportion of low incomes and proportion of pensioners, all significant positive predictors of local T2DM drug use. The GWR model demonstrated considerable spatial variability in the association between T2DM drug use and above predictors and was more accurate. The findings demonstrate the added value of spatial analysis in predicting health care use at local level.