Mortality among participants and non-participants in a prospective cohort study

Socioeconomic position and lifestyle often affect participation in scientific studies. The authors investigated differences in overall and cause-specific mortality between participants and non-participants in the prospective Danish cohort study “Diet, Cancer and Health” and the association between non-participation and mortality by socioeconomic position. A total of 80,996 men and 79,729 women aged 50–64?years, were invited. The authors obtained register data on education, income, death and cause-specific mortality for participants and non-participants and used survival curves to examine differences in overall mortality. Poisson regression models were used to estimate the mortality rate ratio (MRR) by socioeconomic group and by cause of death of participants and non-participants. After a median follow-up of 13?years (5–95 percentiles, 5–14?years), the MRRs for overall mortality among non-participants were 2.09 (95?% CI 1.99–2.14) and 2.29 (95?% CI 2.19–2.40) among men and women, respectively compared with participants. After adjusting for socioeconomic position, the MRRs changed to 1.73 (95?% CI 1.66–1.79) and 2.10 (95?% CO 2.01–2.20) among men and women, respectively. The MRRs did not level out after up to 15?years of follow-up. The MRRs were all significantly increased and ranged from 1.51 to 4.28 for men, depending on the cause of death, and from 1.60 to 3.99 for women. Clear differences in mortality from all investigated causes of death were found between participants and non-participants, which persisted after up to 15?years of follow-up. Socioeconomic position had little effect on this result.     

Short- and long-term mortality after acute myocardial infarction: comparison of patients with and without diabetes mellitus

Aims To compare short- and long-term mortality after a first acute myocardial infarction (AMI) in patients with and without diabetes mellitus. Methods and results A nationwide cohort of 2,018 diabetic and 19,547 nondiabetic patients with a first hospitalized AMI in 1995 was identified through linkage of the national hospital discharge register and the population register. Follow-up for mortality lasted until the end of 2000. At 28 days and 5 years respectively, absolute mortality risks were 18 and 53% in diabetic men, 12 and 31% in nondiabetic men, 22 and 58% in diabetic women, and 19 and 42% in nondiabetic women. Crude mortality was significantly higher in diabetic patients than in nondiabetic patients in both men (28-day hazard ratio (HR) 1.55; 95% confidence interval (CI) 1.32–1.81, 5-year HR 2.01; 95% CI 1.84–2.21) and women (28-day HR 1.19; 95% CI 1.03–1.37, 5-year HR 1.53; 95% CI 1.40–1.67). After multivariate adjustment, risk differences became nonsignificant at 28 days, but diabetes was still associated with a significantly higher long-term mortality in both men (28-day HR 1.16; 95% CI 0.99–1.36, 5-year HR 1.49; 95% CI 1.36–1.64) and women (28-day HR 1.12; 95% CI 0.97–1.28, 5-year HR 1.39; 95% CI 1.27–1.52). The interaction between diabetes mellitus and gender did not reach significance in the analyses. Conclusion Our findings in an unselected cohort covering a complete nation show a significantly higher long-term mortality after a first acute myocardial infarction in diabetic patients. Yet, short-term mortality is not significantly higher in diabetic patients. Risks appear to be equally elevated in men and women.     

Estimation of absolute fracture risk among middle-aged and older men and women: the EPIC-Norfolk population cohort study

While estimates of relative risks associated with risk factors such as age and bone mineral density (BMD) may be of interest for etiologic and comparative purposes, clinical questions such as who might benefit most from preventive interventions or BMD monitoring depend on estimates of absolute fracture risk. The European prospective investigation into cancer (EPIC)-Norfolk study included 25,311 participants (11,476 men) aged 4,079 years in 1993–1997. All participants were followed for osteoporotic fractures to March 2007. Ten-year absolute risk of fracture in men and women were calculated using the baseline survivor function in multivariable Cox proportional-hazards models adjusting for age, sex, history of fractures, body mass index, smoking, and alcohol intake. In comparison of those without history of fracture versus those with history of fracture, the 10-year absolute risk of any fracture in men ranged from 1.0 vs. 1.2% at age 40 years to 3.0 vs. 4.4% at age 75 years. The respective estimates in women ranged from 0.7 vs. 1.0% at age 40 years to 9.3 vs. 17.2% at age 75 years. Statistically significant interaction between age and sex was found (P < 0.001), which contributed to the differences in predicted absolute fracture risks for men and women at different ages. Our study shows the need for population-specific data to develop efficient well calibrated algorithms for assessment of fracture risk. The interaction observed between sex and age points to the need for further prospective studies among men.     

Diabetes and modifiable risk factors for cardiovascular disease: the prospective Million Women Study

To compare the effect of potentially modifiable lifestyle factors on the incidence of vascular disease in women with and without diabetes. In 1996–2001 over one million middle-aged women in the UK joined a prospective study, providing medical history, lifestyle and socio-demographic information. All participants were followed for hospital admissions and deaths using electronic record-linkage. Adjusted relative risks (RRs) and incidence rates were calculated to compare the incidence of coronary heart disease and stroke in women with and without diabetes and by lifestyle factors. At recruitment 25,915 women (2.1% of 1,242,338) reported current treatment for diabetes. During a mean follow-up of 6.1 years per woman, 21,928 had a first hospital admission or death from coronary heart disease (RR for women with versus without diabetes = 3.30, 95% CI 3.14–3.47) and 7,087 had a first stroke (RR = 2.47, 95% CI 2.24–2.74). Adjusted incidence rates of these conditions in women with diabetes increased with duration of diabetes, obesity, inactivity and smoking. The 5-year adjusted incidence rates for cardiovascular disease were 4.6 (95% CI 4.4–4.9) per 100 women aged 50–69 in non-smokers with diabetes, 5.9 (95% CI 4.6–7.6) in smokers with diabetes not using insulin and 11.0 (95% CI 8.3–14.7) in smokers with diabetes using insulin. Non-smoking women with diabetes who were not overweight or inactive still had threefold increased rate for coronary disease or stroke compared with women without diabetes. Of the modifiable factors examined in middle aged women with diabetes, smoking causes the greatest increase in cardiovascular disease, especially in those with insulin treated diabetes.     

Comparison of participants and non-participants in a population study of injuries. The study of men born in 1913 and 1923

In a population study of injuries in two samples from the general population of G?teborg, Sweden, of altogether about 1200 50- and 60-year-old men, the non-participation rates were 25% and 19% respectively. The aim of this report was to estimate the size of the bias caused by non-participation. Besides comparing official register data, e.g., marital status, dwelling conditions and mortality between non-participants and participants, it was also possible to measure certain morbidity variables by using the register of an emergency department over a 7-year period. The non-participants had less stable dwelling conditions and were more often unmarried, divorced or widowed than the participants. They also had more accidents per person and more head injuries, were more often transported to the emergency department by ambulance, tended to have more serious injuries and had a higher mortality rate during follow-up. The non-participants were about six times more often inebriated at the attendance and the differences seemed to be associated mainly with the alcohol factor and less with the participation factor. In conclusion, the bias in incidence estimates caused by non-participation appears to be small to moderate in this type of study as long as the non-participation rate can be kept on the same level as in this study or lower.     

Non-response in a survey of cardiovascular risk factors in the Dutch population: determinants and resulting biases

BACKGROUND: The aim of the research was to study the determinants of participation in a health examination survey (HES) which was carried out in a population that previously participated in a health interview survey (HIS) of Statistics Netherlands, and to estimate the effect of non-participation on both the prevalence of the main HES outcomes (risk factors for cardiovascular disease) and on relationships between variables. METHODS: Logistic regression was used to study the determinants of participation in the HES (n=3699) by those who had previously participated in the HIS (n=12,786). Linear models were used to predict the main outcomes in non-participants of the HES. Item non-response was handled by multiple imputation. RESULTS: HES participants had a higher socio-economic status and comprised more 'worried well', while the rural population were less likely to participate in the HES. Most predicted values of outcomes in HES non-participants differed from those in HES participants, but much of this was due to differences in the age and gender composition of both groups. Taking age and gender differences into account, most predicted values of outcomes in the entire HIS population were within the 95% confidence intervals of the HES values, with the exception of body height in men and high-density lipoprotein cholesterol, fasting glucose and body weight in women. These differences are most likely to be due to the higher socio-economic status of HES participants. Relationships between HIS variables did not change significantly when using HES participants alone compared with all HIS participants. CONCLUSIONS: Despite a high rate of non-participation, some bias, mostly small, was seen in the prevalence rates of the main outcome variables. Bias in the relationships between variables was negligible.     

Non-participation in a population-based seroprevalence study of vaccine-preventable diseases

To estimate the immunity of the Dutch population against vaccine-preventable diseases, a population-based serum bank was established. Since a multi-tiered approach to enroll eligible individuals was used, both the overall non-response selection and the effect, on this selection, of including additional participants and of excluding a subgroup of non-participants (i.e. those without questionnaire data) could be studied. For some characteristics associated with non-participation, an association with seroprevalence of vaccine-preventable diseases is likely (e.g. age, gender). For other characteristics (e.g. marital status, receipt of reminder, degree of urbanization) the association with immune status is unclear but probably small. If the distribution in the population, or information on all participants and non-participants, of the characteristic is available, then the effect on the seroprevalence can be estimated. However, investigators have to be aware that studying only a subgroup of non-participants might lead to a biased insight into non-participation selection. Furthermore, merely including additional participants might not always reduce this bias.     

Hostility and Trajectories of Body Mass Index Over 19 Years: The Whitehall II Study

The authors examined the associations of hostility measuredin adulthood with subsequent body mass index (BMI; weight (kg)/height(m)²) assessed at 4 time points over a 19-year period (1985–2004)in a United Kingdom cohort study. A total of 6,484 participants(4,494 men and 1,990 women) aged 35–55 years at baseline(1985–1988) completed the Cook-Medley Hostility Scale.BMI was assessed upon medical examination in phases 1 (1985–1988),3 (1991–1993), 5 (1997–1999), and 7 (2002–2004).Mixed-models analyses of repeated measures showed clear evidenceof increasing BMI over follow-up in both sexes. In women, higherlevels of hostility were associated with higher BMI at baseline,and this effect remained constant throughout the follow-up period.In men, hostility levels were also strongly associated withBMI at baseline, but results for the interaction between timeand hostility also suggested that this association increasedover time, with persons in the highest quartile of hostilitygaining an excess of 0.016 units (P = 0.023) annually over thefollow-up period as compared with persons in the lowest quartile.The authors conclude that the difference in BMI as a functionof hostility levels in men is not stable over time. body mass index; health behavior; hostility; psychology     

Characteristics of non-participants and reasons for non- participation in a population survey in Kin-Hu, Kinmen

The aim was to characterize non-participants and to investigate reasons for non-participation in a health survey in Kin-Hu township, Kinmen, Republic of China. The non-participants represented 25.6% of the target population of 4451 registered residents aged 30 and older. Baseline demographic characteristics and two-year mortality for the participants and non-participants were compared. A house-to-house visit was attempted to all of the non-participants for reasons of refusal. The mean age of the non- participants was significantly older than that of the participants (54.3 versus 48.5 years, p < 0.001). The response rate for women was significantly higher than that for men (77.2% versus 71.6%, p < 0.001). The probability of death was significantly different between the two groups (1.2% versus 8.8% for participants and non-participants, respectively, p < 0.001). Major reason for not having participated in the health survey was not notified or informed of the examination (32.7%). These data suggest that non-participants were less healthy.     

Factors Associated With Non-participation in a Face-to-Face Second Survey Conducted 5 Years After the Baseline Survey

Background

Non-participation in second surveys is reported to be associated with certain baseline characteristics; however, such data are unavailable for Japanese populations. Although disease incidence during follow-up might influence participation, few reports have addressed this possibility. This study sought to identify factors associated with non-participation in a second survey of a population-based cohort, and to evaluate the influence of self-reported disease incidence on non-participation.

Methods

After excluding participants who left the area (n = 423), died (n = 163), and withdrew from the study (n = 9) among 12 078 participants in a baseline survey for the Japan Multi-Institutional Collaborative Cohort Study in the Saga region between 2005 and 2007, 11 483 people were invited by mail to participate in a face-to-face second survey between 2010 and 2012. The 5-year clinical health history of non-participants was assessed by mail or telephone. Baseline characteristics and self-reported clinical outcomes of non-participants were compared with those of participants.

Results

Among 11 483 people, 8454 (73.6%) participated in the second survey, and 2608 out of 3029 non-participants answered mail or telephone health surveys. Female sex, youngest and oldest ages, lower education, lower occupational class, current smoking, lower physical activity level, shorter sleep time, obesity, and constipation were associated with non-participation. Light drinking (0.1–22.9 g ethanol/day) was associated with participation. Non-participants reported a significantly higher incidence of cancer and a significantly lower proportion of hypertension compared with participants.

Conclusions

Both baseline characteristics and disease incidence during the follow-up period had significant associations with non-participation in the face-to-face second survey.Key words: non-participation, second survey, cohort, socioeconomic factors, lifestyle-related factors     

Participants and non-participants of different categories in a health survey. A cross-sectional register study

Participants and non-participants in a health survey of asbestos cement workers were compared, using data from public registers, i.e. variables of socio-medical relevance. The plant closed down in 1976 and 3 years later all living subjects, 985 persons, were offered a health examination. The participation rate was 57%. The non-participants were divided into four categories: I, those who answered the invitation but refused to participate; II, those who did not answer even after three invitations; III, those who answered and accepted but did not participate; and IV, those who participated partly. A very consistent pattern of differences between participants and non-participants was observed, the latter being significantly more often registered for Public Assistance, for heavy drinking habits or criminal offences, and had significantly lower incomes and occupational status. The sickness absence, however, was not significantly shorter among the participants. The non-participating categories II and III differed most from the participants. Category I was more similar to the participants than to the other non-participating categories. This heterogeneity of the non-response/non-participation concept should be considered when health survey data are interpreted.     

Characteristics of non-participants in comprehensive health examinations ("Otasha-kenshin") among an urban community dwelling elderly: basic research for prevention of the geriatric syndrome and a bed-ridden state

PURPOSE: The present study was conducted to identify the characteristics of non-participants in secondary comprehensive health examinations among community-dwelling elderly. METHODS: The subjects were 728 men and 984 women aged 70 years and over who had participated in comprehensive health examinations in 2002. Multiple logistic regression analysis was performed to assess the characteristics associated with non-participation in comprehensive health examinations after 2 years (in 2004). RESULTS: The rates of participation in follow-up health examinations were 66.3% for men and 67.3% for women. Logistic regression analysis showed that male non-participants had low cognitive function (odds ratio (OR) = 2.19, 95% confidence interval (CI) = 1.07-4.49), low education (OR = 1.58, 95% CI = 1.22-2.22), and suffered from health problems (OR = 1.82, 95% CI = 1.27-2.59), and that female non-participants had low cognitive function (OR = 2.01, 95% CI 1.13-3.59), tended to be smokers (OR = 2.05, 95%, CI = 1.13-3.72), and had no hobby (OR = 0.68, 95% CI = 0.50-0.92). CONCLUSION: Poor cognitive function, health problems, and unfavorable lifestyle factors are related to non-participation in comprehensive health examinations. PROPOSAL: It is necessary to devise various approaches to encourage participation of such individuals.     

Psychosocial risk factors, weight changes and risk of obesity: the Copenhagen City Heart Study

The aim of the study was to establish the effects of a range of psychosocial factors on weight changes and risk of obesity. The study population consisted of the 4,753 participants in the third (1991–1994) and fourth wave (2001–2003) of the Copenhagen City Heart Study, Denmark. At baseline the participants were asked comprehensive questions on major life events, work stress, vital exhaustion, social network, economic hardship, and intake of sleep medication. Weight and height were measured by health professionals. Weight changes and incident obesity was used as outcome measures. The participants on average gained 2 kg of weight and 8% became obese during follow-up. The experience of major life events in childhood, work life and adult life was associated with weight gain and obesity in women, but not in men. Vital exhaustion was associated with weight gain in a dose–response manner in men (P = 0.002) and younger women (P = 0.02). Persons with high vital exhaustion gained approximately 2 kg more during follow-up compared to those with no vital exhaustion. Women with high vital exhaustion were also more likely to become obese during follow-up (OR = 2.39; 95% CI: 1.14–5.03). There were no clear patterns in the associations between social network, economic hardship and weight gain or obesity. The number of psychosocial risk factors, as an indicator for clustering, was not associated with weight gain or obesity. In conclusion, major life events and vital exhaustion seem to play a role for weight gain and risk of obesity, especially in women.     

Impacts of educational level and employment status on mortality for Japanese women and men: the Jichi Medical School cohort study

The objective of this study was to examine educational levels and employment status as independent determinants of overall and cause-specific mortality in a Japanese population. Participants were 4,301 men and 6,780 women in a multi-center community-based prospective study, and data of the baseline survey was collected between 1992 and 1995. The participants were followed up until December 31, 2002 (the average follow-up period was 9.17 years). Early termination of education was associated with an increased risk of mortality from all causes for both men and women. This tendency was more prominent in women aged 59 and younger (hazard ratio (HR) = 3.82, 95% confidence interval (CI): 1.18–12.34), after adjusting for confounding factors using the Cox proportional hazard models. Similar trends were shown for men; specifically, cardiovascular disease mortality for all men was increased by early termination of education (HR = 2.97, 95% CI: 1.17–7.52) compared to later termination. For employment status, unemployed men showed increased mortality from all causes compared to white-collar workers (HR = 1.51, 95% CI: 1.00–2.28). Female farmers and forestry workers showed reduced mortality from all causes compared to white-collar workers (HR = 0.55, 95% CI: 0.33–0.93). Male farmers and forestry workers also showed reduced mortality from cardiovascular diseases compared to white-collar workers (HR = 0.34, 95% CI: 0.14–0.82). Educational level and employment status may affect mortality for Japanese women and men.Funding: The Foundation for the Development of the Community, Tochigi, Japan.     

Randomized intervention trial on preventive home visits to older people: baseline and follow-up characteristics of participants and non-participants

AIMS: In controlled intervention studies, a selective non-response or refusal to participate at baseline may bias measurable effects of the intervention. The aim of this study was to compare mortality and nursing home admission among older persons who accepted (participants) and older person who declined (non-participants) to join a controlled feasibility trial, and to describe and evaluate defined subgroups of non-participants. METHODS: Prospective controlled three-year intervention study (1999-2001) in 34 Danish municipalities with five-year follow-up. Randomization and intervention (education of municipality employees) was done at municipality level. In total 5,788 home-dwelling 75- and 80-year-olds living in these municipalities were invited to participate in the study. Written consent was obtained from 4,060 persons (participation rate 71%). RESULTS: During five-year follow-up non-participants had a higher mortality rate (survival analysis risk ratio RR = 1.5, 95% CI = 1.3-1.7, p<0.0001) and a higher rate of nursing home admissions (RR = 1.7, 95% CI = 1.3-2.1, p<0.0001) compared with participants. Subgroups of non-participants describing themselves as "too ill" and persons "not reached" had a significantly higher mortality rate and risk of admission to nursing home than participants, whereas the subgroups of non-participants describing themselves as "too healthy" and having "another reason for refusal" did not differ from the participants. There was no difference in mortality rates between non-participants living in intervention municipalities compared with non-participants living in control municipalities. CONCLUSIONS: Mortality and nursing home admissions were higher among non-participants. Selection participation bias was of no clinical importance since subgroups of non-participants eligible for the intervention did not differ from the participants.     

Association of a diabetes risk score with risk of myocardial infarction,stroke, specific types of cancer,and mortality: a prospective study in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam cohort

To evaluate the impact of a recently developed, non-invasive risk score predictive for type 2 diabetes on the incidence and mortality of cardiovascular diseases and specific types of cancer. A total of 23,455 participants from the population-based European Prospective Investigation into Cancer and Nutrition (EPIC)–Potsdam study aged 35–65 years and free of diabetes and major chronic diseases at baseline (1994–1998) were followed through 2006 for incident myocardial infarction, stroke, types of cancer, and death. Risk score points were assigned to each participant based on age, waist circumference, height, physical activity, history of hypertension, smoking, alcohol consumption, and intake of red meat, whole-grain bread, and coffee. Hazard ratios (HRs) were estimated by Cox regression models. In age- and sex-adjusted analyses, participants with a high risk score (5-year probability to develop diabetes ≥ 10%) had significantly higher risks of myocardial infarction (HR 2.7, 95% CI 1.5–5.0) and stroke (1.9, 1.0–3.6), but not of colon, breast or prostate cancer incidence, than those with a low score (5-year probability < 1%). In addition, participants with a high risk score had considerably higher risks of cardiovascular (HR 4.6, 95% CI 2.3–9.4), cancer (1.7, 1.1–2.7), and total mortality (2.4, 1.8–3.4), the latter being equivalent to a difference in life expectancy of 13 years. These data indicate that a risk score predictive for type 2 diabetes is also related to elevated risks of myocardial infarction, stroke, and premature death in apparently healthy individuals and emphasize the need for early intervention in high-risk individuals.     

Mortality risks among heavy-smokers with special reference to women: a long-term follow-up of an urban population

Increased mortality risks associated with smoking are well established among men. There are very few population-based studies comprising a sufficient number of heavily smoking women, measuring the direct effect of smoking on mortality risks. Between 1974 and 1992, 8,499 women and 13,888 men attended a health screening programme including reporting of smoking habits. Individuals were followed for total mortality until 2005. All-cause, cancer, cardiovascular, lung cancer and respiratory mortality were calculated in smoking categories <10 g per day, 10–19 g per day, and ≥20 g per day with never-smokers as a reference group and with adjustments for co-morbidities, socio-economic and marital status. For respiratory mortality and lung cancer adjustments for FEV₁, socio-economic and marital status were performed. Smoking was associated with a two to almost threefold increased mortality risk among women and men. The relative risk (RR) with 95% confidence interval, (CI) for women who smoked 10–19 g per day was 2.44 (2.07–2.87), and for those who smoked 20 g per day or more the RR (95% CI) was 2.42 (2.00–2.92). Smoking was a strong risk factor for cardiovascular mortality among women, the RR (95% CI) for women who smoked 10–19 g per day was 4.52 (3.07–6.64). Ex-smoking women showed increased risks of all-cause mortality; RR (95% CI) 1.26 (1.04–1.52) cancer (excluding lung cancer); RR (95% CI) 1.42 (1.07–1.88) and lung cancer RR (95% CI) 2.71 (1.02–7.23) mortality. However, the cardiovascular; RR (95% CI) 1.18 (0.69–2.00) and respiratory; RR (95% CI) 0.79 (0.16–3.84) mortality risks were not statistically significant. This study confirms that as for men, middle-aged heavily smoking women have a two to threefold increased mortality risk. Adjustments for co-morbidity, socio-economic and marital status did not change these results.     

Heart failure and the risk of stroke: the Rotterdam Study

Patients with heart failure used to have an increased risk of stroke, but this may have changed with current treatment regimens. We assessed the association between heart failure and the risk of stroke in a population-based cohort that was followed since 1990. The study uses the cohort of the Rotterdam Study and is based on 7,546 participants who at baseline (1990–1993) were aged 55 years or over and free from stroke. The associations between heart failure and risk of stroke were assessed using time-dependent Cox proportional hazards models, adjusted for cardiovascular risk factors (smoking, diabetes mellitus, BMI, ankle brachial index, blood pressure, atrial fibrillation, myocardial infarction and relevant medication). At baseline, 233 participants had heart failure. During an average follow-up time of 9.7 years, 1,014 persons developed heart failure, and 827 strokes (470 ischemic, 75 hemorrhagic, 282 unclassified) occurred. The risk of ischemic stroke was more than five-fold increased in the first month after diagnosis of heart failure (age and sex adjusted HR 5.79, 95% CI 2.15–15.62), but attenuated over time (age and sex adjusted HR 3.50 [95% CI 1.96–6.25] after 1–6 months and 0.83 [95% CI 0.53–1.29] after 0.5–6 years). Additional adjustment for cardiovascular risk factors only marginally attenuated these risks. In conclusion, the risk of ischemic stroke is strongly increased shortly after the diagnosis of heart failure but returns to normal within 6 months after onset of heart failure.     

Gender Differences in Effects of Physical Activity on Quality of Life and Resource Utilization

Background: Physical activity is associated with health-related quality of life (HRQOL) in the general population, but the effects may be different between sexes. In addition, the effects on resource utilization are not well elucidated. Methods: A population-based cross-sectional survey was conducted in a rural town, and follow-up data were obtained after 1 year. Physical activity was measured in two ways: amount and maximum intensity. The association between physical activity and the MOS Short Form-36 (SF-36) at baseline, and hospitalization, sick days, and medications in the following year were assessed by multiple regression models. Results: Among 4018 adult residents eligible, 3529 (62.4%) had completed the follow-up questionnaire. A greater amount of exercise was positively correlated with all domains of the SF-36: 2.4–9.5 increase in 100-scale at baseline, but association between maximum intensity and SF-36 was observed in only women. It was also associated with a 20–50% higher utilization of over-the-counter drugs in the following year in both sexes, but the effects of maximum intensity on sick days had different directions for men (relative risk, 2.0–2.4) and women (relative risk, 0.3–0.5). Conclusion: The amount of physical activity had positive effects on HRQOL for both men and women, but women had more preferable effects of maximum intensity on HRQOL and resource utilization than men.     

Parity-related mortality: shape of association among middle-aged and elderly men and women

Parity is associated with mortality among middle-aged women, while substantially less is known about this relationship for men and the elderly. Using the census-based Israel Longitudinal Mortality Study (ILMS) II (1995–2004) we sought to examine the parity–mortality relationship among men and women, middle-aged and elderly. In our study cohort of 71,733 married men and 62,822 married women ages 45–89 years at baseline, 19,437 deaths were reported. Mortality differentials by parity were assessed using Cox proportional hazard regression models adjusted stepwise for age, origin, education and number of rooms. Analyzes were carried out for middle-aged (45–64 years) and elderly (65–89 years) men and women separately. We observed a non-linear relationship between parity and mortality for all individuals even after adjustment for demographic and socio-economic variables. In fully adjusted models, for example, nulliparous middle-aged women experienced the highest mortality risks (hazard ratios [HR] = 1.57, 95% confidence intervals [CI] 1.24, 1.98) followed by those with one child (HR = 1.29, 95% CI 1.10, 1.51). These results were attenuated somewhat for nulliparous older women (HR = 1.25, 95% CI 1.11, 1.41). The detrimental effects of low and high parity on mortality among both men and women suggest a non pregnancy-related pathway that is likely mediated by biological and psychosocial factors and other lifestyle characteristics that have long-term consequences into older ages. Further research is warranted to examine the effects of parity by specific cause of death.