Syed Moniruzzaman

Trends in hip fracture incidence rates among the elderly in Sweden 1987–2009

BACKGROUND Previous trend studies have shown large increases in hip fracture incidence rates among the elderly. International research, however, suggests a levelling off, or decline, of hip fracture incidence rates, although for Sweden this remains to be studied. METHODS Data were obtained regarding hip fractures among individuals 65 years and above from 1987 to 2009. Analysis was performed in three steps. First, age- and sex-specific trends in hip fracture rates per 100 000 and the mean age when sustaining a hip fracture were analysed. Secondly, the annual percentage change was used to compare time periods that helped to quantify changes in secular trends. Finally, linear and Poisson regression models were used to examine the trend data and observed rates. RESULTS The absolute number of hip fractures among the elderly in Sweden has largely remained constant between 1987 and 2009, while incidence rates have decreased for all age- and sex-specific groups, with the largest changes in the younger age groups and among women. The mean age of sustaining a hip fracture has increased for both men and women. CONCLUSIONS This study supports other international studies in showing a decrease in hip fracture incidence rates among the elderly, especially since the mid-1990s.

Economic development as a determinant of injury mortality : a longitudinal approach

Cross-sectional studies have produced clear inverted U-shaped curves between injury mortality and economic development; yet, this does not mean that single countries will necessarily follow similar curves as they grow richer over time. This study was conducted to examine whether previous cross-sectional findings can be verified using a longitudinal approach. Data for both injury mortality and gross domestic product (GDP) per capita were obtained from an official health database for the member countries of the Organization for Economic Cooperation and Development (OECD) for the period of 1960-1999. Regression models were then used to examine the longitudinal relationship between these two variables. Substantial improvements in injury mortality were observed in all income categories in the selected countries. For higher and middle high-income countries, injury mortality rates (all causes) increased until 1972, peaking in 1972 and then declining. For industrialized countries with relatively low GDP, injury mortality rates increased until 1977 and then declined. Using cubic regression lines for injury mortality rates, for all income categories, injury mortality rates increased up to a GDP per capita of USD 3,000-USD 4,000, then decreased significantly. The rising trends of suicide and homicide rates were observed until countries attained a GDP per capita of around USD 13,000-USD 14,000 for all income categories. It is noteworthy that compared to the intentional injury categories, mortality due to road traffic accidents and injuries from falls declined earlier on in the economic development process. Longitudinal analysis among high-income countries confirms earlier cross-sectional findings; that is, most injury categories seem to follow inverted U-shaped trend lines, with declining trends after peaking at various stages of temporal and economical development. A comparison between time and economy suggests that differences in peaking time between countries for the same injury category is partly a reflection of temporal differences in economic development.

Can we trust cross-sectional studies when studying the risk of moisture-related problems indoor for asthma in children?

Most studies studying dampness as a risk factor for asthma are of a cross-sectional design. The aim of this study was to investigate if the association between moisture-related problems indoor and asthma found in cross-sectional questionnaire data can be confirmed in longitudinal analyses. The Dampness in Building and Health (DBH) study started in 2000 in Värmland, Sweden, with a baseline questionnaire to all children aged 1–5 y (n = 14,077) and five years later a follow-up questionnaire was distributed to children aged 6–8 y (n = 7,509). Moisture-related problems that were associated with asthma in cross-sectional analysis decreased or disappeared in the longitudinal analysis. However, the association between reports of moldy odor in the homes at baseline and incident asthma remained and became stronger. Our results suggest that cross-sectional data showing associations between moisture-related problems in homes and asthma in children partly can be explained by reporting bias.

Age- and sex-specific analysis of homicide mortality as a function of economic development: A cross-national comparison:

Aims: This study examined the association between homicide rates and GNP per capita (as a measure of economic development) among all age- and sex-specific groups in 53 countries. Methods: Cross-sectional data on homicide rates by age- and sex- specific groups were obtained for 53 countries from World Health Statistics Annual 1996. The association between homicide rates and economic development was studied by using two methods: (1) with regression analysis and (2) by categorizing the data into four income-based country groups and then comparing the differences in their mean values. Results: Results indicate that there was a negative correlation between homicide rates and economic development. The association between homicide rates and country GNP per capita became stronger with increasing age. Pearsons product moment correlation coefficient was strongest among older age groups (65+year) in both sexes (male, r=-0.77 and female, r=-0.71). The correlation was weakest and positive among 1- to 4-year-old children (males, r=0.17 and females, r=0.07). The homicide rate among females was highest for <1-year-old children in low income countries (LICs) (12.8 per 100,000). Conclusions: Lower middle-income countries are in the stage of high priority where both homicide rates and homicide as percentage of total death are high, and its impact was greatest for young males. However, infanticide as a public health problem seems highly concentrated in the poorest countries, while homicide among small children, 1—4 years old, appears to be a universal phenomenon across all nations.

The SELMA Study: A Birth Cohort Study in Sweden Following More Than 2000 Mother-Child Pairs.

BACKGROUND  This paper describes the background, aim and study design for the Swedish SELMA study that aimed to investigate the importance of early life exposure during pregnancy and infancy to environmental factors with a major focus on endocrine disrupting chemicals for multiple chronic diseases/disorders in offspring. METHODS The cohort was established by recruiting women in the 10th week of pregnancy. Blood and urine from the pregnant women and the child and air and dust from home environment from pregnancy and infancy period have been collected. Questionnaires were used to collect information on life styles, socio-economic status, living conditions, diet and medical history. RESULTS Of the 8394 reported pregnant women, 6658 were invited to participate in the study. Among the invited women, 2582 (39%) agreed to participate. Of the 4076 (61%) non-participants, 2091 women were invited to a non-respondent questionnaire in order to examine possible selection bias. We found a self-selection bias in the established cohort when compared with the non-participant group, e.g. participating families did smoke less (14% vs. 19%), had more frequent asthma and allergy symptoms in the family (58% vs. 38%), as well as higher education among the mothers (51% vs. 36%) and more often lived in single-family houses (67% vs. 60%). CONCLUSIONS These findings indicate that the participating families do not fully represent the study population and thus, the exposure in this population. However, there is no obvious reason that this selection bias will have an impact on identification of environmental risk factors.

Cross-national injury mortality differentials by income level: The possible role of age and ageing

OBJECTIVES To examine age- and cause-specific injury mortality differentials between low-income (LICs), middle-income (MICs) and high-income countries (HICs), and to discuss their implications in explaining changing injury mortality patterns with economic development against the background of general health transition theory. STUDY DESIGN Cross-sectional study. METHODS The World Health Organizations mortality database was used as the source of injury mortality data. The grouping into LICs, MICs and HICs was based on data from World Development Indicator. RESULTS Unintentional injury mortality (UIM) rates in children and adults are highest in LICs and MICs, respectively. UIM rates in the elderly population, however, increase with higher economic conditions and are highest in HICs. CONCLUSION Based on these findings, it is hypothesized that ageing and injury interplay mutually with regard to health transition; declining rates in child UIM with economic development contributes to the ageing process, while increasing UIM among the elderly, in combination with ageing populations, boosts the absolute number of injury deaths in this segment.

A comparison of hip fracture incidence rates among elderly in Sweden by latitude and sunlight exposure.

Background: Research has shown that hip fracture risk increases with latitude; hypothetically due to reduced sunlight exposure and its effect on bone quality. Sweden, with large differences in latitude and UV radiation, is ideal to study in order to analyse the association between latitude and UV radiation on age- and sex-specific hip fracture rates among elderly. Method: Aggregated (2006–2008) age- and sex-specific hip fracture data was obtained for each Swedish municipality as well as the municipality’s latitudinal coordinates and aggregated (2006–2008) UV radiation levels. Pearson correlations were calculated between hip fracture incidence rates, latitude and UV radiation. Independent t tests were calculated on tertile-categorized latitudinal data in order to investigate the difference in hip fracture risk between these categories. Results: Statistically significant correlations were seen in all groups between hip fracture incidence rates and latitude as well as UV radiation. The independent t tests showed that this correlation was mainly due to high incidence rates in high latitude municipalities. Conclusions: Statistically significant correlations are seen between hip fracture incidence rates and latitude as well as UV radiation in Sweden and the northern parts of Sweden have an increased risk of hip fractures compared to the middle and southern parts. To our knowledge this is the first study using a national discharge register that shows this relationship and provides a starting point for further research to investigate why populations in northern Sweden have a higher risk of hip fractures compared to other Swedish regions.

Levels of endotoxin in 390 Swedish homes: determinants and the risk for respiratory symptoms in children

Endotoxins are microbiological agents which ubiquitously exist in an indoor environment, and are believed to be causal agents for a number of diseases. This study investigated the indoor levels and determinants of endotoxins and their impact on asthma and allergy diseases among Swedish pre-school children. House dust samples from 390 homes of 198 case children with asthma and allergy and 202 healthy control children were collected in the Dampness Building and Health (DBH) study. House dust endotoxin levels in the childs bedroom and living rooms ranged from 479–188,000 EU/g dust and from 138–942,000 EU/g dust, respectively. Pet-keeping and agricultural activities were significantly associated with the higher endotoxin concentration levels in indoor dust. Endotoxins in theindoor environment did not associate to asthma and allergy diseases in the children. However, we found an association between endotoxins and the presence of disease symptoms in the sub-group of families without indoor pets.

Fall-related fracture trends among elderly in Sweden – exploring transitions among hospitalized cases

PROBLEM Fall-related injuries have been a cause of worry during the end of the 20th century with increasing trends among the elderly. METHOD Using data from the Swedish National Patient Register (NPR) based on hospital admissions, this study explores the trends in fall-related fractures between 1998 and 2010. RESULTS The data shows a decreasing trend in fall-related fractures in all age- and sex-specific groups apart from men 80 years and above. While hip fracture incidence rates decreased in all age- and sex-specific groups, both central fractures and upper extremity fractures have increased in all age- and sex-specific groups apart from women 65-79 years. Lower extremity fractures have increased in the older age groups and decreased in the younger. DISCUSSION The differences found between the groups of fractures and by age- and sex-specific groups indicate a possible transition where more serious fractures are decreasing while less serious fractures increase among hospitalized cases. SUMMARY Perhaps due to a focus on hip fracture prevention, this study shows that while the incidence rate of hospitalized hip fractures has decreased, other fall-related hospitalized fractures have increased. IMPACT ON INDUSTRY Potentially, this could be indicative of a healthier younger elderly, coupled with a frailer older elderly requiring more comprehensive healthcare also for less serious injuries. Further research is needed to confirm our results.

Hospitalized fall-related injury trends in Sweden between 2001 and 2010

Previous studies have indicated increasing trends of hospitalized fall-related injuries amongst elderly. Whether this is true also in Sweden is unknown though it is important to study considering the potential societal impact. Data were obtained regarding hospitalized injuries with falls as external cause among those aged 65 years and above with information on injury type, gender and age, on a yearly basis, from 2001 to 2010. Age- and sex-specific incidence rates were calculated (per 100,000 population) for all fall-related injuries, and for each injury type and trend lines were drawn. Linear regression analyses and percentage change were calculated for the types of fall-related injuries. A decreasing incidence was observed in the younger age groups (65–79 years) with greater decreases amongst women (women: −14.6%, men 65–79 years: −10.5%). However, increasing rates were observed in the older age group (80 years and above), with greater increases amongst men (women: 4.3%, men: 11.4%). Superficial injuries showed greater increases than fractures amongst those aged 80 years and above. This study indicates that older elderly in Sweden are increasingly being hospitalized for less serious injuries. This changing injury panorama is important to include in the future planning of both health care and fall-related prevention.