A randomized walking trial in postmenopausal women: effects on physical activity and health 10 years later

BACKGROUND

It is important to determine if permanent lifestyle changes may result from physical activity interventions and whether health may be affected by these changes.

OBJECTIVE

To conduct a 10-year follow-up of physical activity and self-reported health status in participants of a randomized clinical trial of walking intervention.

METHODS

Of the original 229 volunteer postmenopausal women who participated in the original clinical trial, 196 (N = 96 intervention and 100 controls) completed the 10-year follow-up telephone interview. The interview protocol included questions on self-reported walking for exercise and purposes other than exercise, the Paffenbarger sport and exercise index, functional status, and various chronic diseases and conditions.

RESULTS

The median values for both usual walking for exercise and total walking were significantly higher for walkers compared with controls (for both, P = .01), with median differences of 706 and 420 kcal/wk, respectively. After excluding women who reported heart disease during the original trial, 2 women in the walking group (2%) and 11 women in the control group (12%) reported physician-diagnosed heart disease over the last 10 years (P = .07). There were also fewer hospitalizations, surgeries, and falls among women in the walking group, although these differences were not statistically significant (P>.05).

CONCLUSIONS

Although limited by self-report, this study may be the first to demonstrate long-term exercise compliance to a randomized control trial in older women and to suggest that health benefits may have ensued as a result of these increased activity levels.

Was there an epidemic of diabetes in nonwhite adolescents in Allegheny County, Pennsylvania?

OBJECTIVE

To determine the incidence of IDDM in children aged < 20 years at diagnosis in Allegheny County, Pennsylvania, for the period from 1 January 1990 to 31 December 1994 and to compare the incidence between whites and nonwhites in the same area and for the same time period.

RESEARCH DESIGN AND METHODS

All new patients diagnosed between January 1990 and December 1994 who were aged < 20 years, on insulin, and residents of Allegheny County at diagnosis were identified from medical records of 23 hospitals in the Allegheny County area. To verify the completeness of the hospitals using the capture-recapture method, pediatricians and diabetologists were used as a secondary source.

RESULTS

A total number of 257 patients were identified. The overall age-standardized incidence rate was 16.7/100,000. Nonwhites had a slightly higher incidence (17.6/100,000) than whites (16.5/100,000). In the 15-19 years age-group, the incidence in nonwhites (30.4/100,000) was almost three times higher than that in white (11.2/100,000) and more than two times higher than that in the previous period (from 1985 to 1989) (13.8/100,000).

CONCLUSIONS

For the first time in the Allegheny County registry, and in any other registry, nonwhites showed a higher incidence of IDDM than whites. The high incidence in the 15-19 years age-group was responsible for this phenomenon. This epidemic of diabetes in adolescent nonwhites may be the result of a rising incidence of classical IDDM or another type of diabetes. Further studies using population-based registries are needed to determine whether this increase is being seen in other areas and other ethnic groups and to clarify the reasons for the increase in IDDM among blacks.

Childhood diabetes in China. Enormous variation by place and ethnic group

OBJECTIVE

To investigate the incidence rate of IDDM in China.

RESEARCH DESIGN AND METHODS

The Chinese IDDM registry was established in 1991 as part of the World Health Organization's Multinational Project for Childhood Diabetes (DiaMond) project. Twenty-two centers were developed to monitor the incidence of IDDM in children < 15 years of age. The population under investigation includes > 20 million individuals, representing approximately 7% of the children in China. Capture-recapture methods were used to estimate the ascertainment.

RESULTS

The overall ascertainment-corrected IDDM incidence rate in China was 0.51 per 100,000, the lowest rate ever reported. There was a 12-fold geographic variation (0.13-1.61 per 100,000). In general, the incidence rate was higher in the north and the east. There was a sixfold difference among ethnic groups (highest: Mongol group, 1.82 per 100,000; lowest: Zhuang group, 0.32 per 100,000).

CONCLUSIONS

China has an extremely low overall IDDM incidence rate. China also has the greatest geographic and ethnic variation seen for any country.

Occupational lung diseases and global occupational health on the Net

Occupational lung disease is a major area of concern in occupational health, exhibiting a diverse panorama across countries. While pneumoconiosis is deemed to be the most common occupational disease in many developing countries, emphasis is shifting towards asbestos-related lung diseases and occupational asthma in industrialized countries. Following the Occupational Health for All strategies set forth by the World Health Organization, we propose that a model system based upon the Global Health Network can serve as an effective vehicle towards the prevention of occupational lung diseases on a global scale. It has the potential to: (1) enhance transmission of data and collaboration with the primary health care system in disease surveillance; (2) strengthen research and information transfer and (3) promote education and training at all levels of prevention, with a possible application to the interpretation of chest radiograms.

Dog bite incidence in the city of Pittsburgh: a capture-recapture approach

OBJECTIVES

The purpose of this study was to estimate the number of dog bite injuries occurring in the city of Pittsburgh in 1993.

METHODS

The capture-recapture method was used, along with long-linear modeling. Three sources were used to identify victims hospital reports, animal control reports, and police/victim reports.

RESULTS

In 1993, 790 dog bites were reported. The capture-recapture method estimated that there were 1388 unreported dog bites, with an estimated incidence rate of 58.9 per 10,000.

CONCLUSIONS

Dog bite is a common our preventable injury. To improve surveillance, the focus should be on educating the general public about the serious consequences of dog bite injuries.

IDDM incidence in a multiracial population. The Hawaii IDDM Registry, 1980-1990

OBJECTIVE

The Hawaii IDDM Registry was created to determine the incidence rate of IDDM among children aged < 15 years of Oahu between 1980 and 1990. Because of the multiracial population living in Hawaii, it is an ideal state in which to study the effect of migration on IDDM incidence.

RESEARCH DESIGN AND METHODS

Data were collected by a retrospective hospital chart review and physician survey. Registry criteria included 0-14 years of age at IDDM diagnosis and primary residence on Oahu. Children who were military dependents were excluded. Denominator data were compared from two sources.

RESULTS

A total of 113 new-onset IDDM cases were identified. Case ascertainment was 97%. The unadjusted annual incidence rate was 7.04-7.61 per 100,000 (95% CI 5.83-9.19), depending on which denominator source was used. Race- and ethnicity-specific rates varied greatly (all rates per 100,000): part Hawaiian, 15.34-16.58; Caucasian, 6.21-6.71; Filipino, 3.66-3.96; and Japanese, 2.85-3.08. Temporally, the incidence fluctuated between a low of 2.96 per 100,000 in 1981 to highs of 11.11 and 11.85 per 100,000 in 1985 and 1989, respectively. Ascertainment-corrected rates for these years (3.70, 11.76, and 13.48 per 100,000, respectively) show that the fourfold incidence increase between 1980 and 1989 was not due to ascertainment differences.

CONCLUSIONS

IDDM incidence among children < 15 years of age in Hawaii was the lowest documented in the U.S. The incidence among part-Hawaiian children was 2.5 times greater than that of Caucasian children in Hawaii. IDDM incidence rates among Japanese children in Hawaii were comparable with rates in Japan. The temporal variation in IDDM incidence corresponded with a mid-1980s pandemic of IDDM documented elsewhere.

Time to conception after orchidopexy: evidence for subfertility?

OBJECTIVE

To determine whether time to conception is increased among men who were formerly bilaterally or unilaterally cryptorchid compared with a group of matched control men.

DESIGN

Retrospective cohort study.

SETTING

Human volunteers in an academic research environment.

PATIENT(S)

Men who underwent orchidopexy between 1955 and 1971 at the Children's Hospital of Pittsburgh (n = 547) and a group of matched control men (n = 463) were surveyed by questionnaire.

RESULT(S)

Of the men who attempted paternity, the mean time to conception for the bilateral cases, unilateral cases, and control men was 33.90, 11.11, and 8.78 months, respectively. Kaplan-Meier survival analysis showed a significantly longer time to conception among bilateral cases compared with unilateral cases and controls, but not between unilateral cases and control men. Adjustment for confounders and covariates using a Cox Proportional Hazards model showed that former bilaterally cryptorchid men were 68% (95% CI = 55% to 81%) less likely than former unilaterally cryptorchid men or controls to conceive per month of unprotected intercourse.

CONCLUSION(S)

Time to conception was increased among former bilaterally cryptorchid men compared with both former unilaterally cryptorchid and control men. However, there were no significant differences in time to conception between the unilateral cryptorchid men and the control men.

Paternity after bilateral cryptorchidism. A controlled study

OBJECTIVE

To compare paternity among men with former bilateral cryptorchidism (referred to as the bilateral group) with a group of men with former unilateral cryptorchidism (referred to as the unilateral group) and a control group.

DESIGN

Epidemiologic survey of study cohort.

SETTING

Large urban pediatric hospital.

SUBJECTS

Men with former bilateral and unilateral cryptorchidism who underwent orchiopexy between 1955 and 1971 at the Children's Hospital of Pittsburgh, Pittsburgh, Pa, and a group of control men have been surveyed by questionnaire concerning paternity and factors related to paternity.

MAIN OUTCOME MEASURE

Paternity.

RESULTS

Among the married men who had bilateral cryptorchidism, 50% had fathered children, compared with 76% in the control group and 74% in the unilateral group. Data were similar when the men who were cohabitating were included with the married men. When men who had married and had attempted paternity were evaluated, 62% of the men in the bilateral group had been able to father children compared with 94% of the control group and 89% of the men in the unilateral group. No relationship was noted between the age of orchiopexy or lifestyle factors and paternity. Paternity among all groups was related to female-related infertility factors and to the presence of varicoceles.

CONCLUSIONS

Paternity was compromised after bilateral cryptorchidism when compared with men with former unilateral cryptorchidism and a control group. Among the bilateral group, infertility is about 3.5 times as frequent than the unilateral group and more than 6 times as frequent among the control group. No correlation was found between age of orchiopexy and paternity for either group.

Geographic variation in mortality among individuals with youth-onset diabetes mellitus across the world. DERI Mortality Study Group. Diabetes Epidemiology Research International

The aim of this study was to evaluate the geographic variation in mortality among individuals with youth-onset insulin-dependent diabetes mellitus (IDDM) across the world. The study was based on the currently available IDDM incidence and mortality data. Mortality data for diabetes in the 0-24 year age group were obtained from the World Health Organization (WHO) statistics. The mortality rates were adjusted for the frequency of occurrence of IDDM and dividing the mortality rates by the IDDM incidence rates which were obtained from the WHO DiaMond project. There was a more than 10-fold geographic variation in mortality between the developed countries and Eastern European populations. The areas with the highest mortality rates were located in Japan, Eastern Europe and Russia. The areas having the best outcome associated with IDDM were Northern Europe, Central Europe, and Canada. An ecological study demonstrated a relationship between the incidence-adjusted mortality (estimated case-fatality) with IDDM incidence itself (Spearman's correlation coefficient = 0.45) as well as infant mortality and life expectancy at birth. These data demonstrated the possibility of an enormous geographic variation in mortality of youth-onset diabetic patients even in developed countries. It is important to note that these excess deaths are potentially preventable. The ecological study also suggested that the mortality differences may be in part related to overall and diabetes related care.

The need for a global health disaster network

When a disaster occurs, a major difficulty is knowing where to find accurate information, and how to help coordinate efforts to share accurate information in a quick and organized manner. The establishment of a global information network, that is in place before a disaster occurs, could link all the communication efforts for relief. We propose that a Global Health Unit for Disaster and Relief Coordination be set up as part of the Global Health Network, utilizing the Internet as its backbone. This Unit would establish the links for the disaster information mosaic.

Calendar time trends of the insulin-dependent diabetes mellitus mortality in Allegheny county, Pennsylvania

This study applied a Cox proportional hazard model to investigate the calendar time trends of insulin-dependent diabetes mellitus (IDDM) mortality. The study population was the IDDM patients who were diagnosed in the period 1965-1979, less than or equal to 19 years of age at diagnosis, and were residents of Allegheny County, PA. The mortality follow-up for each individual was recorded from the diagnosis of IDDM and till 31 December 1990. There were 999 individuals in this study, and 68 deaths (6.8%) occurred during this 26-year investigation period. Overall, for the patients with the same IDDM duration, non-whites were 1.7 times more likely to die than white group; female IDDM patients had a higher risk of death than male IDDM patients (1.27:1); and the risk of mortality increased as the age at diagnosis increased. When controlling for the gender, ethnic groups and age at onset effect, the risk of dying in different calendar years appeared to be a quadratic form. The highest mortality appeared in the late 60's, and the lowest was in the period of 1975-1979. Disappointingly the mortality has begun to rise again in the latest time frame.

Paternity after unilateral cryptorchidism: a controlled study

OBJECTIVE

To determine if paternity is decreased among formerly unilateral cryptorchid men compared with a control group of men.

SUBJECTS AND METHODS

Formerly unilateral cryptorchid men who had orchiopexy between 1955 and 1971 at the Children's Hospital of Pittsburgh and a group of control men have had their medical records reviewed and have been surveyed by questionnaire.

RESULTS

Among the men who had ever married and had attempted paternity, significantly more of the unilateral cryptorchid men had been unable to father children (10.5%) than among the control group (5.4%). No difference was found when the groups were compared for the duration of regular intercourse without contraception to conception of their first child. There was no relationship between the age of orchiopexy or lifestyle factors and paternity or between the age of orchiopexy and months of regular unprotected intercourse to conception. Paternity among both groups was related to female-related infertility factors and to the presence of varicoceles.

CONCLUSION

When compared with a control group, paternity was compromised after unilateral cryptorchidism. Infertility is about twice as frequent among the unilateral group. There was no evidence of subfertility requiring a longer exposure of regular intercourse without contraception among the fertile subgroup. No correlation was found between age of orchiopexy and paternity.

The incidence of insulin-dependent diabetes mellitus in urban districts of Shanghai (1989-1993)

A retrospective study on the incidence of insulin-dependent diabetes mellitus (IDDM) among children aged 0-14 years was carried out from 1989-1993 in urban Shanghai, China. The average annual population at risk (0-14 yr) consisted of 1,401,664 children. All the cases were collected from the hospitals (primary source) and from primary and middle schools and kindergartens (second source) with independent validation of case ascertainment. There were 53 IDDM cases from the primary source, 23 from the secondary source, with a total of 58. The ascertainment corrected total number of IDDM cases was 67 by the capture-recapture method. The average crude annual incidence rate was 0.83 [95% confidence interval (CI) 0.61-1.04] and ascertainment corrected incidence rate 0.96 (95% CI 0.80-1.12) per 100,000. Peak incidence fell in 1992 and in the 9 year-old group. The incidence of childhood IDDM in the urban districts of Shanghai was reconfirmed to be the lowest in the world but by comparing the results of former investigations a trend was found of increasing incidence of IDDM.

A major improvement in the prognosis of individuals with IDDM in the past 30 years in Japan. The Diabetes Epidemiology Research International Study Group

OBJECTIVE

To evaluate the time trends of mortality among individuals with IDDM in Japan.

RESEARCH DESIGN AND METHODS

A historical prospective study of two independent population-based cohorts composed of individuals who were diagnosed between 1965 and 1969 (1960s cohort) and between 1975 and 1979 (1970s cohort), which included 286 IDDM patients (onset age < 18 years) for the 1960s cohort and 779 patients for the 1970s cohort, was performed. After 10 years of observation, mortality status and causes of deaths between the two cohorts were compared.

RESULTS

The age-adjusted mortality rate per 100,000 person-years of the 1960s cohort was 754 (95% CI, 471-1,141); in contrast, that of the 1970s cohort was only 196 (95% CI, 107-329) (P < 0.001). The standardized mortality ratio of the 1960s cohort was 1,432 (95% CI, 898-2,161), and that of the 1970s cohort was 489 (95% CI, 267-821). Analyses of the causes of deaths revealed a marked decline in recent years in the number of deaths by acute complications and renal disease.

CONCLUSIONS

A major decline in the mortality of diabetic children in Japan may be attributed to the dramatic changes in the quality of care and medical infrastructure that occurred after the mid-1970s.

Socioeconomic and behavioural risk factors for mortality of individuals with IDDM in Japan: population-based case-control study. Diabetes Epidemiology Research International (DERI) US-Japan Mortality Study Group

The aim of this population-based, one-to-one matched-pair case-control study was to evaluate the factors concerning the markedly increased risk for dying among Japanese subjects with insulin-dependent diabetes mellitus (IDDM) from a social and behavioural perspective. The study was based on the population-based cohort of IDDM subjects in the Diabetes Epidemiology Research International Mortality Study. We studied 90 cases who died and 90 living control subjects, selected from the rest of the cohort, who were matched for sex, birth year, year of diagnosis and duration of diabetes. Socioeconomic and behavioural status were surveyed through a questionnaire. Conditional logistic regression analyses based on 55 respondent pairs revealed that the better educated patients (year of completing education: odds ratio = 0.66) who kept the same physician (number of times a patient changed physician: odds ratio = 2.77) and who attended a clinic specializing in diabetes (attendance at university hospital clinic: odds ratio = 0.18) injecting insulin several times a day (number of injections, odds ratio = 0.31) and more frequently attending the clinic (> or = 12 times per year, odds ratio = 0.23) were at substantially lower risk of death. The results begin to profile the patients with the highest risk of dying who could be identified earlier and undergo intervention treatment.

Efficiency and accuracy of disease monitoring systems: application of capture-recapture methods to injury monitoring

Capture-recapture methods were employed to determine the most accurate and efficient approaches to monitor adolescent injuries. Multiple sources were used to ascertain cases of adolescent injuries that occurred between September 1 and December 31, 1991, in a single school district in metropolitan Pittsburgh, Pennsylvania. Eliminating the duplicate cases between the sources revealed 144 verified injuries; 127 (88.2%) were identified by student monthly recalls, 33 (22.9%) by daily attendance records, 58 (40.3%) by medical excuses, and 72 (50.0%) by a 4-month student recall. Capture-recapture analyses were undertaken to assess potential dependencies between the sources, to estimate the degree of underascertainment in the population, and to evaluate the efficiency of the individual sources and the combinations between them. It was estimated that 91% of the cases in the population were ascertained when all four methods of case finding were utilized. Furthermore, the analysis indicated that accurate injury estimates could be achieved using combinations of only two or three of the sources. An analysis of the efficiency of the methods of ascertainment revealed a trade-off between effort (the number of hours needed to identify cases) and the precision (coefficient of variation) of the injury estimates. Capture-recapture analysis not only provided an approach to evaluate and adjust for undercount but also offered a formal means to evaluate the most efficient combination of the sources to maximize completeness while minimizing effort. The use of these techniques has the potential to evaluate and improve injury surveillance as well as other disease monitoring systems.

Incidence of systemic lupus erythematosus. Race and gender differences

OBJECTIVE

To examine racial differences in the incidence of systemic lupus erythematosus (SLE).

METHODS

A population-based registry of SLE patients in Allegheny County, Pennsylvania, was used to identify incident cases of SLE diagnosed between January 1, 1985 and December 31, 1990, from 3 sources, by medical record review (University of Pittsburgh Lupus Databank, rheumatologists, and hospitals). Capture-recapture methods using log-linear models were used to estimate the level of case-finding and to calculate 95% confidence intervals (CI). Incidence rates were calculated per 100,000 population.

RESULTS

A total of 191 definite and 78 probable incident cases of SLE were identified, and the overall annual incidence rates were 2.4 (95% CI 2.1-2.8) and 1.0 (95% CI 0.8-1.3), respectively. The crude incidence rates of definite SLE were 0.4 for white males, 3.5 for white females, 0.7 for African-American males, and 9.2 for African-American females. The annual incidence rates of definite SLE remained fairly constant over the study interval. African-American females with definite SLE had a younger mean age at diagnosis compared with white females (P < 0.05). Since the overall ascertainment rate was high (85%; 95% CI 78-92%), the ascertainment-corrected incidence rate for definite SLE, 2.8 (95% CI 2.6-3.2), was similar to the crude rate.

CONCLUSION

Our rates clearly confirm previous reports of an excess incidence of SLE among females compared with males and among African-Americans compared with whites. We have used capture-recapture methods to improve the accuracy of SLE incidence rates, and we advocate their use to facilitate comparisons across studies.

Reproducibility and validity of an epidemiologic questionnaire to assess past year physical activity in adolescents

The reproducibility and validity of a past year physical activity questionnaire was determined in a sample of 100 adolescents aged 15-18 years, randomly selected from a population-based cohort. Subjects completed four 7-day recalls of activity approximately 3 months apart. The average of the four 7-day recalls of activity was utilized as the "gold standard" against which the past year questionnaire was compared to evaluate validity. The questionnaire was also validated against objective measures, such as physical fitness and body mass index. Interscholastic team rosters were utilized to directly validate the reporting of specific activities. One-month and one-year test-retest reproducibility of the questionnaire were determined. For different measures of activity, the Spearman correlations between the questionnaire and the average of the 7-day recalls ranged from 0.55 to 0.67 in males and 0.73 to 0.83 in females, all significant at p < 0.01. In general, although there was no association between the past year activity questionnaire results and objective measures, there was a significant, albeit weak association between the physical activity questionnaire and time to complete a 1-mile (1.61-km) run (r = -0.47) in females. Subjects reported participating in specific interscholastic sports with an accuracy of 100%, 86%, and 95% for the fall, winter, and spring sports, respectively. Test-retest reproducibility was higher over one month (r = 0.79) than over one year (r = 0.66). These data provide evidence that the questionnaire yields a reasonable estimate of past year or "habitual" physical activity in adolescents.