Ólöf Anna Steingrímsdóttir

Educational inequalities in mortality over four decades in Norway: prospective study of middle aged men and women followed for cause specific mortality, 1960-2000.

Objectives To determine the extent to which educational inequalities in relation to mortality widened in Norway during 1960-2000 and which causes of death were the main drivers of this disparity. Design Nationally representative prospective study. Setting Four cohorts of the Norwegian population aged 45-64 years in 1960, 1970, 1980, and 1990 and followed up for mortality over 10 years. Participants 359 547 deaths and 32 904 589 person years. Main outcome measures All cause mortality and deaths due to cancer of lung, trachea, or bronchus; other cancer; cardiovascular diseases; suicide; external causes; chronic lower respiratory tract diseases; or other causes. Absolute and relative indices of inequality were used to present differences in mortality by educational level (basic, secondary, and tertiary). Results Mortality fell from the 1960s to the 1990s in all educational groups. At the same time the proportion of adults in the basic education group, with the highest mortality, decreased substantially. As mortality dropped more among those with the highest level of education, inequalities widened. Absolute inequalities in mortality denoting deaths among the basic education groups minus deaths among the high education groups doubled in men and increased by a third in women. This is equivalent to an increase in the slope index of inequality of 105% in men and 32% in women. Inequalities on a relative scale widened more, from 1.33 to 2.24 among men (P=0.01) and from 1.52 to 2.19 among women (P=0.05). Among men, absolute inequalities mainly increased as a result of cardiovascular diseases, lung cancer, and chronic lower respiratory tract diseases. Among women this was mainly due to lung cancer and chronic lower respiratory tract diseases. Unlike the situation in men, absolute inequalities in deaths due to cardiovascular causes narrowed among women. Chronic lower respiratory tract diseases contributed more to the disparities in inequalities among women than among men. Conclusion All educational groups showed a decline in mortality. Nevertheless, and despite the fact that the Norwegian welfare model is based on an egalitarian ideology, educational inequalities in mortality among middle aged people in Norway are substantial and increased during 1960-2000.

Variation in reporting of pain and other subjective health complaints in a working population and limitations of single sample measurements.

&NA; Measuring health complaints by administrating a single report is common. Our aim was to assess variation in pain and other subjective complaints over an extended period, whether a single‐sample produces representative data, and determine associations between complaints. Health‐complaint reports were collected from postal workers at monthly intervals over a period of 32–34 consecutive months (1997–2000). We computed six compound complaint‐severity indices of 30 complaint‐severity scores (intensity score×duration score, scale 0–9). In 67% of the scores, the complaints exhibited larger deviation from a reference (12 consecutive reports in the last 24 months of the study period) when using one report from the respective reference period compared with the mean of two consecutive reports. Four consecutive samples were needed to obtain agreement for 95% of the data when the criterion of accepted deviation from the reference was set to ±1.0. Neither inspection of graphs nor statistical tests revealed any seasonal pattern or trend on either a group or individual level. The musculoskeletal and psychological complaint‐severity indices correlated strongly (rs>0.66). Correlations between the different somatic indices were generally weak or moderate (rs<0.55). The initial report produced higher complaint ratings than subsequent reports did. Due to large intra‐individual complaint variability and higher complaint‐severity level exhibited on the initial report compared to those that followed, measuring subjective health with a single‐sample approach does not produce data representativeness for average complaints over a period. More than two samples should be collected when the purpose is to reveal changes in health.

Twin studies of pain

Twin studies provide a method for estimating the heritability of phenotypes and for examining genetic and environmental relationships between phenotypes. We conducted a systematic review of twin studies of pain, including both clinical and experimental pain phenotypes. Fifty‐six papers were included, whereof 52 addressed clinical phenotypes. Of the most comprehensively studied phenotypes, available data indicates heritability around 50% for migraine, tension‐type headache and chronic widespread pain, around 35% for back and neck pain, and around 25% for irritable bowel syndrome. However, differences in phenotype definitions make these results somewhat uncertain. All clinical studies relied on dichotomous outcomes and none used pain intensity as continuous phenotype. This is a major weakness of the reviewed studies and gives reason to question their validity with respect to pain mechanisms. Experimental pain studies indicate large differences in heritability across pain modalities. Whereas there is evidence for substantial common genetic risk across many clinical pain conditions, different experimental pain phenotypes appear to be associated with different genetic factors. Recommendations for future research include inclusion of pain intensity scaling and number of pain sites in phenotyping. Furthermore, studies examining the genetic relationships between pain phenotypes, in particular between clinical and experimental phenotypes, should be prioritized.

Sleep and pain sensitivity in adults.

Abstract Sleep problems and pain are major public health concerns, but the nature of the association between the 2 conditions is inadequately studied. The aim of this study was to determine whether a range of sleep measures is associated with experimental increased pain sensitivity. A cross-sectional large population-based study from 2007 to 2008, the Tromsø 6 study, provided data from 10,412 participants (age: mean [SD], 58 [13] years; 54% women). Self-reported sleep measures provided information on sleep duration, sleep onset latency (SOL), and sleep efficiency, as well as frequency and severity of insomnia. The main outcome measure was pain sensitivity tests, including assessment of cold-pressor pain tolerance. We found that all sleep parameters, except sleep duration, were significantly associated with reduced pain tolerance. Both the frequency and severity of insomnia, in addition to SOL and sleep efficiency, were associated with pain sensitivity in a dose–response manner. Adjusting for demographics and psychological distress reduced the strengths of the hazard ratios, but most associations remained significant in the fully adjusted models. There was also a synergistic interaction effect on pain tolerance when combining insomnia and chronic pain. We conclude that sleep problems significantly increase the risk for reduced pain tolerance. Because comorbid sleep problems and pain have been linked to elevated disability, the need to improve sleep among patients with chronic pain, and vice versa, should be an important agenda for future research.

Trends in educational inequalities in cause specific mortality in Norway from 1960 to 2010: a turning point for educational inequalities in cause specific mortality of Norwegian men after the millennium?

BackgroundEducational inequalities in total mortality in Norway have widened during 1960–2000. We wanted to investigate if inequalities have continued to increase in the post millennium decade, and which causes of deaths were the main drivers.MethodsAll deaths (total and cause specific) in the adult Norwegian population aged 45–74 years over five decades, until 2010 were included; in all 708,449 deaths and over 62 million person years. Two indices of inequalities were used to measure inequality and changes in inequalities over time, on the relative scale (Relative Index of Inequality, RII) and on the absolute scale (Slope Index of Inequality, SII).ResultsRelative inequalities in total mortality increased over the five decades in both genders. Among men absolute inequalities stabilized during 2000–2010, after steady, significant increases each decade back to the 1960s, while in women, absolute inequalities continued to increase significantly during the last decade. The stabilization in absolute inequalities among men in the last decade was mostly due to a fall in inequalities in cardiovascular disease (CVD) mortality and lung cancer and respiratory disease mortality. Still, in this last decade, the absolute inequalities in cause-specific mortality among men were mostly due to cardiovascular diseases (CVD) (34% of total mortality inequality), lung cancer and respiratory diseases (21%). Among women the absolute inequalities in mortality were mostly due to lung cancer and chronic lower respiratory tract diseases (30%) and CVD (27%).ConclusionsIn men, absolute inequalities in mortality have stopped increasing, seemingly due to reduction in inequalities in CVD mortality. Absolute inequality in mortality continues to widen among women, mostly due to death from lung cancer and chronic lung disease. Relative educational inequalities in mortality are still on the rise for Norwegian men and women.

Defining chronic pain in epidemiological studies: a systematic review and meta-analysis

Abstract The objective was to document the operational definitions applied in epidemiological studies of chronic pain and to examine whether pain definitions and other methodological factors are systematically related to prevalence estimates. MEDLINE, EMBASE, and PsychINFO were searched for original research reports with study samples of at least 1000 individuals, excluding studies of less than 5 out of 15 selected body regions and studies solely concerned with specific pain conditions. Meta-analyses and meta-regressions were applied with random effects models; covariates were geography, sampling year, survey method, sampling frame, participation rate, percentage women of all participants, pain duration, and pain location. Of 6791 hits, 86 studies were included in the syntheses. The phrasing, content, and combinations of the chronic pain definition criteria were highly inconsistent, with virtually no 2 studies from independent research groups using the exact same criteria. Prevalence estimates ranged from 8.7% to 64.4%, with a pooled mean of 31%. Huge heterogeneity was shown in all forest plots. Prevalence estimates were significantly related to survey method (&bgr; = −10.8 [95% confidence interval: −17.2 to −4.4]), but it only counted for a small fraction of the between-studies variation in the estimates. There were also interaction effect of survey method by sex (female–male prevalence ratio [95% confidence interval]: questionnaire = 1.20 [1.16 to 1.25], and interview = 1.38 [1.29 to 1.47]). The other covariates investigated were not significantly related to the prevalence estimates. Researchers and clinicians should be aware of the probability that interview survey method of collecting data may give lower chronic pain reporting than questionnaire survey method and that this effect may be stronger in men than women.

Do parental education and income matter? A nationwide register-based study on HPV vaccine uptake in the school-based immunisation programme in Norway

Objective Vaccine against human papillomavirus (HPV) has been offered free of charge to all 12-year-old girls in Norway since 2009. Nevertheless, the uptake of HPV vaccine is lower than for other childhood vaccines. The aim of this study was to examine whether parental education and income are associated with initiation and completion of HPV vaccination. Design Nationwide register-based study. Setting Publicly funded childhood immunisation programme in Norway. Participants 91 405 girls born between 1997 and 1999 and registered in the Norwegian Central Population Registry were offered HPV vaccine during the first 3 programme years. Of these, 84 139 had complete information on all variables and were included in the study. Measurements Information on HPV-vaccination status was obtained from the Norwegian Immunisation Registry. Data on socioeconomic factors were extracted from Statistics Norway. Risk differences (RDs) and CIs were estimated with Poisson regression. Results In the study sample, 78.3% received at least one dose of HPV vaccine and 73.6% received all three doses. High maternal education was significantly associated with lower probability of initiating HPV vaccination (multivariable RD=−5.5% (95% CI −7.0% to −4.0%) for highest compared with lowest education level). In contrast, high maternal income was significantly associated with higher probability of initiating vaccination (multivariable RD=10.1% (95% CI 9.0% to 11.3%) for highest compared with lowest quintile). Paternal education and income showed similar, but weaker, associations. The negative association between education and initiation was only seen for incomes below the median value. Conclusions In spite of the presumably equal access to HPV vaccine in Norway, we found socioeconomic disparities in vaccine uptake. More studies are needed to explain the underlying factors responsible for the observed socioeconomic differences. Insight into these factors is necessary to target information and increase vaccination coverage to ultimately reduce HPV-related disease across socioeconomic barriers.

Trends in educational inequalities in old age mortality in Norway 1961−2009: a prospective register based population study

BackgroundThe vast majority of deaths occur in older adults. Paradoxically, knowledge on long-term trends in mortality inequalities among the aged, and particularly for those aged 80 years and over, is sparse. The historical trends in size and impact of socioeconomic inequalities on old age mortality are important to monitor because they may give an indication on future burden of inequalities. We investigated trends in absolute and relative educational inequalities in old age mortality in Norway between 1961 and 2009.MethodsWe did a register-based population study covering the entire Norwegian population aged 65-94 in the years 1961−2009 (1,534,513 deaths and 29,312,351 person years at risk). By examining 1-year mortality rates by gender, age and educational level we estimated trends in mortality rate ratios and rate differences.ResultsOn average, age-standardised absolute inequalities increased by 0.17 deaths per 1000 person-years per year in men (P<0.001), and declined by 0.07 deaths per 1000 person-years per year in women (P<0.001). Trends in rate differences were largest in men aged 75−84 years, but differed in direction by age group in women. The corresponding mean increase in age-standardised relative inequalities was 0.4% and 0.1% per year in men and women, respectively (P<0.001). Trends in rate ratios were largest in the youngest age groups for both genders and negligible among women aged 85−94 years.ConclusionsWhile relative educational inequalities in old age mortality increased for both genders, absolute educational inequalities increased only temporarily in men and changed little among women. Our study show the importance of including absolute measures in inequality research in order to present a more complete picture of the burden of inequalities to policy makers. As even in older ages, inequalities represent an unexploited potential to public health, old age inequalities will become increasingly important as many countries are facing aging populations.

How much of the variation in mortality across Norwegian municipalities is explained by the socio-demographic characteristics of the population?

The goal was to find out whether much of the variation in mortality between the 430 Norwegian municipalities could be attributed to socio-demographic characteristics of the population - operating through individual- or aggregate-level mechanisms. Two-level discrete-time hazard models were estimated for women and men at age 60-89 in 2000-2008, using registers covering the entire population. Year, age and a municipality-level random term were included in the first step. When socio-demographic characteristics of the individual and others in the municipality were added, the variance of the random term was reduced by 73-80% almost exclusively because of aggregate-level effects. Policy implications of these findings are discussed.

Educational differences in life expectancy over five decades among the oldest old in Norway

BACKGROUND Socioeconomic inequalities in life expectancy have been shown among the middle aged and the youngest of the old individuals, but the situation in the oldest old is less clear. The aim of this study was to investigate trends in life expectancy at ages 85, 90 and 95 years by education in Norway in the period 1961-2009. METHODS This was a register-based population study including all residents in Norway aged 85 and over. Individual-level data were provided by the Central Population Register and the National Education Database. For each decade during 1961-2009, death rates by 1-year age groups were calculated separately for each sex and three educational categories. Annual life tables were used to calculate life expectancy at ages 85 (e85), 90 (e90) and 95 (e95). RESULTS Educational differentials in life expectancy at each age were non-significant in the early decades, but became significant over time. For example, for the decade 2000-9, a man aged 90 years with primary education had a life expectancy of 3.4 years, while a man with tertiary education could expect to live for 3.8 years. Similar numbers in women were 4.1 and 4.5 years, respectively. Even among 95-year-old men, statistically significant differences in life expectancy were found by education in the two last decades. CONCLUSION Education matters regarding remaining life expectancy also for the oldest old in Norway. Life expectancy at these ages is low, so a growth of 0.5 years in the life expectancy differential is sizeable.