Epidemiology in transition.
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Epidemiologic Research Design↗
Biomedical subjects
S Wall
Publications and source records attributed to S Wall.
Shifting the distribution of risk: results of a community intervention in a Swedish programme for the prevention of cardiovascular disease.
STUDY OBJECTIVE: To examine the impact of a systematic risk factor screening and counselling carried out by family physicians and family nurses within the larger framework of a community intervention programme for the prevention of cardiovascular disease (CVD). DESIGN: Quasi-experimental study comparing trends in an intervention area with those in a reference area. SETTING: A Northern Sweden municipality (5500 inhabitants) constituted the intervention area while the Northern Sweden region (510,000 inhabitants) served as the reference area. PARTICIPANTS: All 30, 40, 50, and 60 year old inhabitants were invited each year from 1985 to 1992. Among 2046 eligible 1893 participated (92.5%), which formed eight independent cross sections. One cross section, 1986, was re-surveyed forming a panel. MAIN RESULTS: In the cross sections, mean total cholesterol was reduced from 7.09 to 6.27 mmol/l for men (p < 0.001) and from 7.13 to 5.89 mmol/l for women (p < 0.001) and mean systolic blood pressure from 132.2 to 123.7 mm Hg for men (p < 0.05) and from 129.2 to 122.0 mm Hg for women (p < 0.001) during the eight years. Body mass index (BMI) increased from 25.6 to 26.2 for men (p < 0.05) and from 25.0 to 25.5 for women (NS). A corresponding reduction in cholesterol and blood pressure (for women) occurred in the panel, while BMI was unchanged. The risk for CVD, using the Framingham equation, was estimated to be reduced overall by 19% (p = 0.0021) when comparing early cross sections (1985/86) with the later cross sections (1990/91). CONCLUSIONS: It was concluded that a long term community based CVD prevention programme that combines population and individual strategies can substantially promote a health shift in CVD risk in a high risk rural population. The individual attention and evaluation provided by the health provider survey seem to accelerate, but not increase the amount of, risk reduction.
Adult↗
Endovascular repair of abdominal aortic aneurysm using a pararenal fenestrated stent-graft.
PURPOSE: To report an unusual case of endovascular abdominal aortic aneurysm (AAA) exclusion in which a fenestrated stent-graft was used to seal a proximal Type I endoleak. METHODS AND RESULTS: An 84-year-old man with a 6.0-cm AAA underwent an aortomonoiliac aneurysm exclusion procedure that was complicated by a proximal endoleak. Because the patient had no right kidney, an additional stent-graft was designed to cover the right renal artery stump while preserving left renal perfusion through a fenestration in the graft material. This approach was successful in obliterating the endoleak around the proximal attachment site, but flow through the lumbar arteries remained. CONCLUSIONS: The use of a fenestrated stent-graft is feasible, but the type of fenestration in this case has limited applicability owing to the rarity of patients with suitable anatomy.
Aged↗
Distribution of caries in 12-year-old children in Sweden. Social and oral health-related behavioural patterns.
OBJECTIVE: To describe the distribution of caries in 12-year-old children in Sweden according to socio-demographic and oral health related behaviour. PARTICIPANTS: The study group consisted of 3,373 12-year-old children residing in catchments of 26 different public dental health clinics in Sweden, geographically well represented. METHOD: The clinical examination for dental caries was performed by 28 calibrated dentists. A questionnaire on lifestyle was distributed to the children with questions on ethnicity, socio-economic level and oral health as well as overall health attitudes. RESULTS: The proportion of 12-year-old children with no experience of dentine caries was 47% and 35% were completely free from all caries. Intraoral distribution of caries showed most lesions on the first molar mesial surface, with 80% enamel and 20% dentine caries. Almost all children brushed their teeth twice a day and a third of the children had an extra intake of fluoride. Decayed surfaces including enamel caries (DeS) was chosen as a measure of ongoing caries and used when dividing children into three caries groups; caries free (50%), 1-3 lesions (40%) and the high caries group (10%) with more than 3 lesions. These groups showed distribution differences. More non-Swedish children, children from workers' homes, and children who brushed their teeth less than twice a day were found in the high caries group. More children from workers' homes living in big cities and snacking more than once a week were also found in the high caries group. This could not be shown for other social groups. Also children who had an extra intake of fluoride were classified in the high caries group.
Child↗
Short interpregnancy intervals and the risk of adverse birth outcomes among five racial/ethnic groups in the United States.
The authors studied the effects and population-level impact of short (< or = 12 months) interpregnancy intervals on the risks for low (<2.5 kg) birth weight and preterm (<37 weeks) delivery of liveborn singleton infants to US African American, Mexican, Native American, non-Hispanic white, and Puerto Rican mothers (n = 4,841,418) from 1989 to 1991. Statistical analyses were done by using the Mantel-Haenszel correlation statistic chi-square test and logistic regression. The proportion of livebirths associated with < or =12-month interpregnancy intervals was the lowest among non-Hispanic whites (18.5%, 95% confidence interval 18.5-18.5) and the highest among Native Americans (29.7%, 95% confidence interval 29.2-30.2). As compared with mothers with >12-month intervals, mothers with <6-month intervals had an approximately 50% to 80% increased risk of very low (<1.5 kg) birth weight delivery and a 30% to 90% increased risk of very preterm (<32 weeks) delivery. Logistic regression analyses showed that the adverse effects of short intervals were reduced by about 10% but remained for the most part significant after controlling for potential confounding by maternal age, education, parity, marital status, prenatal care, smoking, and previous preterm delivery.
Adult↗
[Public health work is improvement without impairment].
Strategies for community intervention, their evaluation and social patterning are discussed in the article. Theories and methods are called for to enable better assessment of social inequalities in health outcome variables and processes in public health endeavours. With this is a starting point some methodological and ethical issues relating to preventive programmes and their evaluation are identified.
Community Health Services↗
[Public health work needs new evaluation models. Primary care projects are more effective than large scale campaigns].
The need both of critical assessment of community intervention programmes and of alternatives to randomised controlled studies is discussed in the article. Examples are drawn from a review recently completed for the Swedish Council on Technology Assessment in Health Care [Statens Beredning för Utvärdering av medicinsk metodik (SBU)], and from the evaluation of a cardiovascular disease prevention programme currently in progress in northern Sweden.
Cardiovascular Diseases↗
Decline in the prevalence of HIV-1 infection in young women in the Kagera region of Tanzania.
In northwestern Tanzania, a population-based survey of HIV-1 infection in the Kagera region in 1987 demonstrated a high prevalence (24.2%) in adults of Bukoba town, whereas it was lower (10.0%) in the surrounding rural district of Bukoba. In 1993 and 1996, population-based cross-sectional studies were carried out in urban and rural Bukoba districts, respectively, to monitor the time trend in the prevalence of HIV-1 infection in the region. In both studies, a multistage cluster sampling technique was adopted in selecting study individuals. Consenting individuals between 15 and 54 years of age were interviewed using a structured questionnaire. Following individual counseling, blood samples were drawn and tested for HIV infection using enzyme-linked immunosorbent assay (ELISA) antibody detection tests. The overall age-adjusted HIV-1 seroprevalence in urban Bukoba decreased from 24.2% (134 of 553) in 1987 to 18.3% (118 of 653) in 1993 (p = .008). The age-adjusted gender-specific prevalence declined significantly in women, from 29.1% (95 of 325) to 18.7% (74 of 395; p = .0009). Except for men > or = 35 years of age, whose prevalence appeared to have an upward trend between the two studies, all other age groups in both genders had a downward trend; this finding was most significant in women between 15 and 24 years of age (from 27.6% to 11.2%; p = .0004). For the rural population, the overall prevalence decreased from 10.0% (54 of 538) in 1987 to 6.8% (118 of 1728) in 1996 (p = .01). Except for rural women between 15 and 24 years of age whose prevalence decreased from 9.7% (12 of 124) to 3.1% (12 of 383; p = .002), other age groups in the rural populations showed no change in prevalence. Ongoing interventions in this area leading to behavioral change may have contributed to this observation. An incidence study is under way to confirm this observation and to investigate the factors that are responsible for the decline in the HIV-1 prevalence.
Adolescent↗
Screening for diabetic retinopathy by general practitioners: ophthalmoscopy or retinal photography as 35 mm colour transparencies?
In order to assess the relative ability of general practitioners (GPs) to detect diabetic retinopathy (DR), especially sight-threatening diabetic retinopathy (STDR) by direct ophthalmoscopy or by examining, on a separate occasion, retinal images as 35 mm colour transparencies, a South and Mid Wales primary care-based study was performed in four general practices (six GPs). The participating GPs were provided with standardized training and equipment. Both methods were compared to the 'reference' grade of DR provided by the Diabetic Retinopathy Reading Centre (London), based on the same retinal images. Ophthalmoscopy and retinal photography (Canon CR4 45NM) with mydriasis were all practice based. The clinical assessments were based on a protocol developed for screening for DR in Europe. A total of 996 people with diabetes were identified, representing a prevalence of known diabetes of 2.1%. After exclusions on medical grounds, 897 patients were available for screening, of whom 605 (68%) were photographed. Based on the retinal images, the reference centre identified DR in 43% and STDR in 14.4%. In total, 597 valid comparisons between GPs and the reference centre were obtained; of these, 462 (77%) were high quality photographs which were used in subsequent analysis. The sensitivity for detecting any DR increased from 62.6% (95% CI 55.9-69.4) with ophthalmoscopy to 79.2% (95% CI 73.6-84.9) using retinal photographs, specificity remaining essentially unchanged at 75.0 (95% CI 69.5-80.5) and 73.5% (95% CI 68.0-79.1) with the positive predictive value (PPV) increasing from 67.2 (95% CI 60.4-74.0) to 71.0% (95% CI 65.0-77.0), respectively. The detection of STDR sensitivity increased from 65.7 (95% CI 54.4-77.1) with ophthalmoscopy alone to 87.3% (95% CI 79.4-95.2) based on retinal photographs with specificity falling from 93.8 (95% CI 91.4-96.3) to 84.8% (95% CI 81.2-88.5) and PPV from 65.7 (95% CI 54.4-77.1) to 51.2% (95% CI 42.1-60.3), respectively. We conclude that the use of standardized 35 mm colour transparency retinal photographs for screening by trained GPs in a primary care setting achieves an acceptable detection rate (>87%) for STDR, contrasting with ophthalmoscopy alone (66%), which was below the proposed UK standard of 80%.
Diabetes Mellitus, Type 1↗
Perceived health modifies the effect of biomedical risk factors in the prediction of acute myocardial infarction. An incident case-control study from northern Sweden.
OBJECTIVES: To assess the importance of biomedical risk factors, social factors and self-reported health in the prediction of the first event of acute myocardial infarction (AMI) in an apparently healthy middle-aged population. DESIGN: An incident case-control study. SETTING: The study was nested within the Västerbotten Intervention Program and the Northern Sweden MONICA cohorts. SUBJECTS: The study consists of 78 AMI cases with two randomly selected controls per case from the same study cohorts. RESULTS: Significant odds ratios were found for history of diabetes, daily smoking, cholesterol, body-mass index, hypertension, lower education and perceived ill health. In multivariate logistic regression smoking, hypertension and cholesterol of > or =7.8 mmol L(-1) remained significant. An interaction was observed between number of biomedical risk factors and perceived health. CONCLUSIONS: Smoking, hypertension and hypercholesterolaemia explain a major share of incident AMI events in a Swedish middle-aged population. The study further illustrates that perceived ill health negatively modifies the impact of these risk factors.
Case-Control Studies↗
The importance of serum lipoprotein (a) as an independent risk factor for premature coronary artery disease in middle-aged black and white women from the United States.
OBJECTIVE: To determine the association of serum levels of lipoprotein (a) (Lp(a)) with coronary artery disease (CAD) in relation to other risk factor variables in black and white women. DESIGN: Retrospective case-control study. SETTING: Community of Bogalusa, Louisiana and Cardiac Catheterization Laboratory at the Medical Center of Louisiana, New Orleans, USA. SUBJECTS: The study included 47 female cases (52% black; mean +/- SD age: 50.8 +/- 6.3 years) with confirmed myocardial infarction (MI) or at least 75% blockage of one or more major epicardial coronary arteries determined by angiography, and 55 controls (60% black; mean +/- SD age: 49.6 +/- 7.9 years) with no high grade obstructive lesion (< 50% blockage) and no history of CAD. MAIN OUTCOME MEASURES: Lipoprotein variables, homocysteine, body mass index and cigarette smoking. RESULTS: In the whole group, mean values of Lp(a), total cholesterol, low-density lipoprotein cholesterol (LDL-C), apolipoprotein B (apoB) and very-low-density lipoprotein cholesterol (VLDL-C) were higher (P < 0.05-0.001) and apoA-I was lower (P < 0.05) in cases than in controls. The multivariate logistic regression analysis showed elevated levels of Lp(a) (> 500 mg L-1) and LDL-C (> 3.36 mmol L-1) as strong independent risk factors, with odds ratios (with 95% confidence intervals) of 13.6 (4.00-46.30) and 4.64 (1.31-16.49), respectively. ApoA-I, with an odds ratio of 0.11 (0.02-0.64), was a protective factor only at high levels (> 53.6 mumol L-1). Between races, significant odds ratios were noted in the black women for Lp(a) (OR = 15.98; P < 0.01) and LDL-C (OR = 7.69; P < 0.05) and in the white women for only Lp(a) (OR = 15.23; P < 0.01). CONCLUSIONS: Lp(a) is an important risk factor for CAD both in black and in white women.
Black People↗
Lipoprotein(a) and cholesterol levels act synergistically and apolipoprotein A-I is protective for the incidence of primary acute myocardial infarction in middle-aged males. An incident case-control study from Sweden.
OBJECTIVE: To further establish the importance of total plasma apolipoprotein A-I and lipoprotein(a) in the prediction of primary acute myocardial infarction (AMI) in men. DESIGN: An incident case-control study. SETTING: The study was nested within the Västerbotten Intervention Program (VIP) and the Northern Sweden MONICA cohorts. SUBJECTS: A total of 62 male AMI cases and 124 matched controls, randomly selected from the study cohorts. RESULTS: In multivariate logistic regression, significant odds ratios (OR) were found for Lp(a) above 200 mg L-1, apo A-I below the mean value (1136 mg L-1) and total cholesterol (TC) above 7.8 mmol L-1. TC interacted significantly with Lp(a); for Lp(a) above 200 mg L-1 and TC below 6.5 mmol L-1, OR = 5.6; for Lp(a) above 200 mg L-1 and TC above 6.5 mmol L-1, OR = 12.6. To evaluate the potential effect of reducing high levels of Lp(a) or TC on the incidence of AMI in males, the attributable risk percentage (ARP) was calculated when interaction between the two variables was present. ARP is 31% for Lp(a) and 21% for TC, implying that 31% of the cases are due to high Lp(a) and 21% of the cases are due to high TC levels. CONCLUSIONS: In the Swedish male population, total apo A-I in plasma is a protective factor and a plasma Lp(a) level above 200 mg L-1 is a risk factor for AMI in males. A TC level above 6.5 mmol L-1 increased the risk of AMI if the Lp(a) level was above 200 mg L-1, suggesting Lp(a) to be useful in identifying high risk individuals needed to be treated.
Apolipoprotein A-I↗
The impact of short stature on child morbidity in a rural African community.
This study was undertaken to assess whether short stature in children under 5 years of age is associated with an increased risk of acute or persistent diarrhoea, acute respiratory infection, or indeed any illness, taking account of possible confounding factors such as whether breastfed, water quality, degree of household crowding, age and gender. After initial anthropometric assessment, the morbidity and diet of a cohort of 403 Somali children were recorded for 1 year at 2-week intervals. In multivariate analyses of the findings, adjustments were made for the possible confounding factors listed. Short stature was associated with an increased incidence of acute diarrhoea (< -2 SD score, RR 1.7, 95% CI 1.3-2.2) and with a risk of developing persistent diarrhoea, but not with the incidence of acute respiratory infections. When adjusting for age only, short stature increased the risk of developing any illness, but this association was not shown when adjusting for the other possible confounding factors. There was a dose-effect relationship between different degrees of short stature and acute diarrhoea, with an increased incidence of acute diarrhoea among the shortest children. Efforts were made to account for the possibility of reverse causality, which seemed not to change the main findings. Thus, short stature seemed to increase the risk of subsequent acute diarrhoea in children under 5 years of age.
Body Height↗
Reduction of selection bias in primary prevention of cardiovascular disease through involvement of primary health care.
OBJECTIVE: To examine selection bias in social and health factors in a community intervention programme for the prevention of cardiovascular disease by comparing programme data with both census data and a random sample of the same population. DESIGN: Cross sectional studies. SETTING: All 35 primary health care centres in Västerbotten County, Sweden. SUBJECTS: 24,870 individuals who during 1992 and 1993 became 30, 40, 50 or 60 years of age. MAIN OUTCOME MEASURES: Total income, socio-economic group, employment, education, body mass index (BMI), total cholesterol, systolic and diastolic blood pressure, and daily smoking. RESULTS: The differences in social characteristics between participants and non-participants were marginal, indicating that the social selection bias was small. However, unemployment, low income, and younger age tended to be associated with somewhat lower preference to participate. The overall pattern of health status, as measured by risk factors, was similar rather than dissimilar. While the participants in the intervention health survey had lower mean total cholesterol, their blood pressure was generally higher compared with the reference random sample. CONCLUSIONS: The primary health care system in Sweden might serve as a useful base for educational health counselling, at least within a community intervention programme, for all levels of society.
Adult↗
Acceptability of voluntary HIV testing with counselling in a rural village in Kagera, Tanzania.
A pilot study on acceptability of voluntary HIV testing with counselling was performed in a rural village in Kagera, Tanzania as a potential intervention against HIV transmission. Village residents were prepared by their leaders and subsequently invited to health education group meetings to volunteer for the test. Consenting individuals were interviewed to determine awareness and acceptance of the offer followed by pre-test counselling and taking of a blood sample for subsequent HIV testing. Two months later, the results of the test were returned with post-test counselling coupled with a short interview of a random sample of adults in the village. Of the 245 adults responding to the call, 137 (55.9%) subsequently volunteered. The main reason for volunteering was to know the HIV status (96%). Among those who were aware of the offer, the main reason for not volunteering was that they felt unlikely to catch AIDS, implying that they had a false perception of being at low risk. In this study a significant proportion were willing to volunteer for the HIV test and to receive the results, indicating a moderate level of acceptability. The results also indicate the need for developing innovative ways of enhancing acceptability of voluntary HIV testing with counselling. However, the relationship between knowledge of HIV status and behavioural change is complex and therefore several potential mechanisms may exist by which HIV testing in combination with counselling can influence behaviour. For this reason, people should be given the choice of knowing their HIV status since it may constitute a potential mechanism for influencing behaviour towards reduction of HIV transmission.
Adolescent↗
Daily air pollution levels and acute asthma in southern Sweden.
This study aimed to investigate the association between daily air pollution levels and the occurrence of acute respiratory signs and symptoms among people with asthma or asthma-like problems. Thirty eight subjects in the southern Swedish city of Landskrona kept a daily diary for 10 weeks. The daily prevalence of symptoms, supplementary bronchodilator use and peak flow deviations were compared with measurements of environmental nitrogen dioxide (NO2), sulphur dioxide, temperature and humidity in the city. The occurrence of severe asthma, both during the day and during the evening, was significantly positively associated with the concurrent 24 h average concentration of NO2, which never exceeded 72 microg x m(-3). A correlation of borderline significance was found between the use of on-demand medication and the NO2 level. However, peak flow deviations were not associated with air pollution or weather conditions, which may be explained by the beneficial effect of bronchodilators used by 28 of the subjects. The results of this study confirm those of some earlier studies and suggest that aggravation of asthma is related to daily variations in air quality, as indicated by relatively low ambient concentrations of nitrogen dioxide. These results also indicate that it may be appropriate to examine severe asthma symptoms separately.
Acute Disease↗
African-American mothers' perception of their residential environment, stressful life events, and very low birthweight.
We performed a hospital-based case-control study of African-American mothers to explore the relation between a mother's perception of her own residential environment and very low birthweight. We administered a structured questionnaire to mothers of very-low-birthweight (<1,500 gm; N = 28) and critically ill non-low-birthweight (>2,500 gm; N = 52) infants. The groups had similar sociodemographic characteristics. The vast majority of participants were unmarried and had no private medical insurance. The odds ratios of very low birthweight fluctuated between 1.7 and 3.2 for African-American mothers who rated their neighborhoods (in terms of police protection, protection of property, personal safety, friendliness, delivery of municipal services, cleanliness, quietness, and schools) unfavorably. Additionally, the odds ratio of very low birthweight for mothers exposed to three or more stressful life events during pregnancy was 3.1 (95% confidence interval = 1.2-8.2). We conclude that African-American mothers' perception of their residential environment and frequency of stressful life events are associated with very low birthweight in their infants.
Adolescent↗
Excess female mortality in rural Somalia--is inequality in the household a risk factor?
Gender differences in mortality risks in rural Somali communities were studied to assess their relation to literacy, marital status and family economy between January 1987 and December 1989. In all, 6947 person-years form the basis for the demographic analysis and estimations of mortality rates and survival. Both sexes showed similar mortality risks in infancy and early childhood, but females demonstrated a greater risk of dying during their reproductive life than males. Respiratory symptoms, diarrhoea, fever and jaundice dominated the symptoms prior to death Illiteracy in women considerably increased the risk of dying from 15 years and onwards particularly when living with literate men. The life expectancy from 15 years was 58 for a literate male but only 42 years for an illiterate woman living with a literate head of household. Multivariate analyses showed after adjustment for marital status and literacy that an excess female mortality from 15 years, but especially from 45 years, was associated to a household situation, where the woman did not subside on farming but on other, mainly commercial, activities. This vulnerability of females was associated to the recession of the economy in the pre-war situation in Somalia, a backlash hitting women trying to earn their living. To conclude, gender differences in a number of factors in the household-literacy, marital status and especially source of income-were disadvantageous for the women, increasing the mortality risk in this setting.
Adolescent↗