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I Kleinschmidt

Publications and source records attributed to I Kleinschmidt.

At least 37 records · Page 2Linked to original sources
PubMed2000

Drug-resistant tuberculosis in South African gold miners: incidence and associated factors.

SETTING: A gold mining company in the Free State Province of South Africa. OBJECTIVE: To document the incidence of and factors associated with drug-resistant tuberculosis (TB) in South African gold miners. DESIGN: Review of Mycobacterium tuberculosis drug susceptibility records for the period from 1 July 1993 to 30 June 1997. RESULTS: Over the study period, 2241 miners had culture-positive M. tuberculosis pulmonary disease where isolates were tested for drug susceptibility to the four primary anti-tuberculosis drugs. The proportions of primary and acquired drug resistance were respectively 7.3% and 14.3% for isoniazid and 1.0% and 2.8% for resistance to at least isoniazid and rifampicin (multidrug resistance). Resistance to streptomycin and ethambutol was uncommon, and rifampicin monoresistance was rare. No significant factors for primary drug resistance were identified. Patients with retreatment pulmonary TB who failed primary TB treatment (versus cure) were significantly more likely to have TB with resistance to any TB drug or MDR (odds ratios respectively 9.82, 95%CI 2.97-33.5, and 18.74, 95%CI 1.76-475). Human immunodeficiency virus (HIV) infection was not significantly associated with primary or acquired drug resistance, and there was no trend of increasing resistance over time. CONCLUSION: Anti-tuberculosis drug resistance has remained stable despite the HIV epidemic and increasing TB rates. Directly observed therapy may have contributed to containing the level of drug resistance. Adherence to and completion of treatment are essential to prevent drug resistance and treatment failure, including in situations with high HIV prevalence.

Adult↗
PubMed2000

The impact of HIV infection on recurrence of tuberculosis in South African gold miners.

UNLABELLED: DESIGN AND OBJECTIVES: Potential risk factors for recurrence of tuberculosis (TB) were investigated in a retrospective cohort study of 305 human immunodeficiency virus (HIV) positive and 984 HIV-negative South African gold miners treated for TB with directly-observed, rifampicin-based regimens. Standard treatment changed from rifampicin, isoniazid and pyrazinamide (RHZ) to RHZ plus ethambutol (RHZE) during the study period. RESULTS: Recurrence occurred in 37 HIV-positive and 46 HIV-negative men. HIV infection was associated with a significantly higher recurrence rate (8.2 vs 2.2 per 100 person-years; multivariate-adjusted incidence rate ratio [IRR] 4.9, 95% confidence interval [CI] 3.0-8.1), as were post-tuberculous scarring (multivariate-adjusted IRR 1.6 for one or two scarred lung zones, 4.0 for three or more zones; test for trend P < 0.001) and drug resistance (multivariate-adjusted IRR 2.7, 95%CI 1.01-7.4). The recurrence rate was significantly higher following treatment with RHZ than RHZE (multivariate-adjusted IRR 2.1, 95%CI 1.1-4.0). The difference between regimens needs to be interpreted with caution, however, as allocation was not randomised. CONCLUSION: The high recurrence rate among HIV-positive men requires further investigation to distinguish relapse from re-infection as the predominant cause, leading to consideration of further intensification of the initial regimen or use of secondary prophylaxis.

AIDS-Related Opportunistic Infections↗
PubMed2000

Factors associated with an increased case-fatality rate in HIV-infected and non-infected South African gold miners with pulmonary tuberculosis.

SETTING: A gold mining company in the Free State Province, South Africa. AIM AND DESIGN: A retrospective cohort study to investigate factors associated with an increased case-fatality rate (CFR) at 6 months in human immunodeficiency virus (HIV) positive and negative tuberculosis (TB) patients. RESULTS: Between April 1993 and March 1997, there were 2236 men with culture-confirmed pulmonary TB in whom HIV status and treatment outcome were known. The overall CFR within the first 6 months of therapy was low (3.6%). After adjusting for confounding factors, HIV infection (OR 15.0, 95%CI 7.4-30.6), self-presentation compared to detection by the active radiological screening programme (OR 5.6, 95%CI 2.6-12.2) and presence of silicosis (OR 3.0, 95%CI 1.4-6.3) were significantly associated with an increased CFR. Opportunistic infections accounted for 56.2% (36/64) of deaths in HIV-positive men. Cryptococcal disease accounted for 75% (27/36) of deaths from opportunistic infections. CONCLUSION: HIV infection and silicosis are both powerful risk factors for TB and are associated with an increased risk of death. Strategies aimed at reducing these two risk factors within the workforce could reduce TB incidence and mortality. In settings with functional DOTS programmes and sufficient resources, expanding the DOTS programme to include active case detection should be explored as a means of reducing TB prevalence and mortality.

AIDS-Related Opportunistic Infections↗
PubMed2000

A double-blind, placebo-controlled, double-centre study of the effects of an oral multivitamin-mineral combination on stress.

OBJECTIVES: To assess the effects of a multivitamin-mineral combination (Berocca Calmag) treatment on stress in a large sample of South Africans. METHOD: This was a multiple-dose, double-blind, placebo-controlled, double-centre study. Patients were drawn from two centres with high stress levels (Durban and Johannesburg), each study recruiting the same number of patients (150) from 1,000 adults with predetermined high stress levels. Dropouts from the study were replaced. Study medication safety was evaluated by recording adverse events. On day 1 (baseline) patients were subjected to an individual in-depth assessment that included a biographical questionnaire, four psychological scales, and collateral information from close relatives. On day 30 (end of the study period) or at the latest 7 days after the last planned medication intake, the assessment was repeated for purposes of pre- and post-response comparison. RESULTS: Thirty-three patients dropped out and were replaced, leaving 300 patients who completed the study--151 in group 1 (multivitamin-mineral combination), and 149 in group 2 (placebo). There were no statistically significant differences between the two groups regarding demographics and baseline stress scores at study entry. Both groups improved between baseline and the end of treatment as assessed. The degree of improvement was statistically significant and greatest in group 1 for all psychometric instruments, with this beneficial effect increasing over the course of the day. Subgroup analyses for age (18-44 and 45-65 years), gender and ethnicity showed no general effect on the overall study outcome. CONCLUSIONS: The multivitamin-mineral combination tested is well tolerated and can be used as part of a treatment programme for stress-related symptoms at the recommended dose.

Adult↗
PubMed1999

The practice and prevalence of dry sex among men and women in South Africa: a risk factor for sexually transmitted infections?

OBJECTIVES: To establish the prevalence of "dry sex" practice in a South African periurban population. To investigate the reasons for and factors influencing the practice of dry sex and to evaluate dry sex practice as a risk factor for sexually transmitted disease (STD). DESIGN: Cross sectional sample survey. METHODS: A random community sample of men and women aged between 16 and 35 in Gauteng Province, South Africa, were interviewed regarding the practice of dry sex using a structured interviewer administered questionnaire. RESULTS: Dry sex practices were reported by 60% of men and 46% of women. Among younger individuals dry sex practice is far more common among the less educated, but there was no significant difference between education groups in the older respondents. A higher proportion of men practising dry sex than not practising dry sex reported having a past history of STD infection (56% versus 41%) although this difference was only marginally significant (p = 0.05). There was no difference in reported history of STD between women who practised dry sex and those who did not. CONCLUSIONS: This study shows that dry sex practice is common in this community. The younger less educated group were the most likely to practise dry sex. Dry sex practice was associated with an increased prevalence of self reported STDs in men but not in women.

Adolescent↗
PubMed1999

South African tuberculosis mortality data--showing the first sign of the AIDS epidemic?

OBJECTIVE: To report on the magnitude and distribution of registered tuberculosis (TB) mortality rates in South Africa for 1994 and 1995 in the context of changes in overall mortality registration. DESIGN: Retrospective analysis of routinely collected data. SETTING: The South African population. SUBJECTS: Deceased persons with death certificates stating TB as cause of death. MAIN OUTCOME MEASURES: Age-adjusted mortality rates for all causes and for TB. RESULTS: There are large, and to some extent unexpected, variations in registered TB mortality in South Africa. For the country as a whole TB mortality has risen from 38 to 53 per 100,000 for males and from 15 to 23 per 100,000 for females for the years 1994 to 1995. In the Eastern Cape TB deaths account for 10% of registered male deaths and 7% of registered female deaths. The two provinces that have the highest HIV prevalence among women attending antenatal clinics, namely KwaZulu-Natal and North West, recorded increases in registered TB deaths of 100% and 75% respectively for males, and 130% and 74% respectively for females. TB deaths among younger women appear to have risen particularly fast in these two provinces. Nationally the proportion of extrapulmonary tuberculosis (ETB) has risen from 5.2% to 7.4% of all TB deaths, pointing to an increase in HIV-related TB deaths. CONCLUSION: The deficiencies and changes in the vital registration system make it difficult to draw firm conclusions from these data, but there is an alarming increase in TB mortality that is unlikely to be an artefact of the data alone. Some of the increase in TB mortality is likely to be due to misreporting of cause of death of AIDS patients. An audit should be conducted to investigate the enormous disparities between vital registration TB mortality, and TB deaths recorded under the TB notification system.

AIDS-Related Opportunistic Infections↗
PubMed1999

Mycobacterial disease in South African gold miners in the era of HIV infection.

SETTING: Mining company tuberculosis (TB) clinic, Freestate Province, South Africa. OBJECTIVES: To investigate the impact of the human immunodeficiency virus (HIV) on tuberculosis case rates and case detection methods in miners. DESIGN: Demographic and clinical data were extracted from the central computerised TB database for the period 1990-1996. RESULTS: A total of 7450 miners had TB, which was smear- or culture-positive in 81% of pulmonary cases. Incidence rates more than doubled between 1990 and 1996, from 1174 to 2476 per 100000 per year. Non-tuberculous mycobacteria, predominantly Mycobacterium kansasii, were isolated more commonly from retreatment than from new cases (19.5% and 11.5% respectively, P < 0.001). HIV prevalence in TB patients increased from 15% in 1993 to 45% in 1996 (P < 0.001). There was no significant association between HIV and smear status, but HIV-positive patients were more likely than HIV-negative patients to present passively with symptoms rather than through the active radiological screening programme (OR 1.9, P < 0.0001). The overall proportion of patients presenting passively increased from 23% in 1990 to 51% in 1996 (P < 0.001). CONCLUSION: The HIV epidemic has lead to increased TB incidence in South African miners to very high rates, and appears to be impacting on the efficacy of the active radiological screening programme.

Adult↗
PubMed1997

Cancer incidence near radio and television transmitters in Great Britain. I. Sutton Coldfield transmitter.

A small area study of cancer incidence in 1974-1986 was carried out to investigate an unconfirmed report of a "cluster" of leukemias and lymphomas near the Sutton Coldfield television (TV) and frequency modulation (FM) radio transmitter in the West Midlands, England. The study used a national database of postcoded cancer registrations, and population and socioeconomic data from the 1981 census. Selected cancers were hematopoietic and lymphatic, brain, skin, eye, male breast, female breast, lung, colorectal, stomach, prostate, and bladder. Expected numbers of cancers in small areas were calculated by indirect standardization, with stratification for a small area socioeconomic index. The study area was defined as a 10 km radius circle around the transmitter, within which 10 bands of increasing distance from the transmitter were defined as a basis for testing for a decline in risk with distance, and an inner area was arbitrarily defined for descriptive purposes as a 2 km radius circle. The risk of adult leukemia within 2 km was 1.83 (95% confidence interval 1.22-2.74), and there was a significant decline in risk with distance from the transmitter (p = 0.001). These findings appeared to be consistent over the periods 1974-1980, 1981-1986, and were probably largely independent of the initially reported cluster, which appeared to concern mainly a later period. In the context of variability of leukemia risk across census wards in the West Midlands as a whole, the Sutton Coldfield findings were unusual. A significant decline in risk with distance was also found for skin cancer, possibly related to residual socioeconomic confounding, and for bladder cancer. Study of other radio and TV transmitters in Great Britain is required to put the present results in wider context. No causal implications can be made from a single cluster investigation of this kind.

Adolescent↗
PubMed1997

Ecological and individual predictors of birthweight in a northern Finland birth cohort 1986.

This multilevel study of spatial variability in, and determinants of, birthweight was conducted using individual and ecological data in a geographically defined prospective birth cohort for 1986 in northern Finland. The study area comprises three large areas defined by latitude: Northern Lapland (NL), Southern Lapland (SL) and Oulu province (OP), comprising 74 localities with a total study population of 9216 singleton births. The mean birthweight was 3482 g for NL, 3537 g for SL and 3587 g for OP (NL vs. OP and SL vs. OP: P < 0.05). The crude rate for stillbirths was highest in NL. The women in the northernmost area were socially less privileged and the localities less prosperous compared with those in the southernmost area. Significant spatial clustering of mean birthweights was found (P = 0.0016), with highest birthweight in the south-western part of the study area. A variable expressing the wealth of each locality, the financial capacity category (FCC), had its lowest mean value in NL, with a range of one to six for the localities studied here. A multilevel multiple regression model showed that, after allowing for sex, gestational age, mother's age, height and hypertensive disorders, parity, body mass index, previous low birthweight child and smoking as individual determinants of birthweight, part of the residual variation could be explained by the locality wealth parameter. Using the multilevel model, the differences in mean birthweight across the three latitude areas persisted but were reduced (difference OP vs. NL reduced from 105 g to 86.5 g). The relationship between birthweight and FCC was inverse U-shaped with the highest mean birthweight estimated for localities occurring in the middle of the range (FCC = 3). The wealthiest urban localities (FCC = 6) and the most deprived localities (FCC = 1) both had a predicted birthweight about 60 g below the maximum at FCC = 3, if all other factors were held constant. This result, taken together with the spatial clustering of birthweights, suggests that there may be important social and environmental determinants of birthweight that have yet to be identified.

Adult↗
PubMed1997

Angiosarcoma of the liver in Great Britain in proximity to vinyl chloride sites.

OBJECTIVES: To study the incidence of angiosarcoma of the liver in England and Wales 1979-86 and Scotland 1975-87. To investigate whether any non-occupational neighbourhood cases occurred near a vinyl chloride site. METHODS: This is a geographical study of incident cases among the general population of Great Britain. Diagnosis of angiosarcoma of the liver was based mainly on the national cancer registry, the world register of cases among vinyl chloride workers, and the register of cases (including histological review) maintained by the Health and Safety Executive. Proximity (< 10 km) of residence to a vinyl chloride site was based on postcode of address at the time of diagnosis. RESULTS: 55 cases were ascribed to angiosarcoma of the liver in England and Wales with a further six cases in Scotland (annual incidence in Great Britain from all sources of around 1.4 cases per 10 million population). There were two cases with documented exposure to Thorotrast, and 10 cases among vinyl chloride workers. There were no vinyl chloride sites in Scotland. Among the 25 cases in England and Wales with histological diagnosis after review by a panel of pathologists, only 15 were confirmed as angiosarcoma, and one of the two Scottish cases after histological review was also confirmed. Overall, 11 cases ascribed to angiosarcoma were resident within 10 km of a vinyl chloride site; nine were vinyl chloride workers, one further case on histological review was not considered to have been correctly diagnosed as angiosarcoma, and the remaining case, confirmed as angiosarcoma, was employed at a vinyl chloride factory during the late 1950s, although not as a vinyl chloride worker. CONCLUSION: The incidence of angiosarcoma of the liver in Great Britain remains extremely rare. The one confirmed case in a non-vinyl chloride worker within 10 km of a site must nevertheless be presumed to have been exposed to vinyl chloride in the workplace. In the period of study, there were no confirmed non-occupationally exposed cases of angiosarcoma among residents living near a vinyl chloride site in Great Britain.

Adult↗
PubMed1997

Variation in incidences of tuberculosis in subgroups of South African gold miners.

OBJECTIVES: To determine risk factors and to identify groups at high risk of tuberculosis (TB) among South African gold miners. METHODS: A retrospective cohort analysis was carried out with hospital and personnel databases on a random sample of the workforce of Freegold Mines, served by Ernest Oppenheimer Hospital, Welkom, South Africa. The outcome measure of interest was a reported first episode of TB while employed at Freegold. A person-years analysis was carried out to estimate incidence ratios between different categories of age group, period, cumulative service, mining occupation, and silicosis status. A separate analysis was carried out on a subgroup of men (non-random) whose HIV status was known. RESULTS: The main finding of the study was that TB was more strongly associated with age than expected with a rate ratio of reported incidence of 21 for the oldest age group compared with the youngest, after adjustment for period, cumulative service, occupation, and silicosis status. There was also a significant association between TB and occupations such as drilling with a rate ratio of 2.3 compared with low dust surface and maintenance workers, after adjustment for age, period, cumulative service, and silicosis. Analysis of the HIV tested subgroup showed that these results are unlikely to be the result of confounding due to HIV infection. Prevalence of HIV in this group has been rising sharply since 1991, but the increase was slowing towards the end of the study period. CONCLUSION: A profile of mineworkers who are at high risk of TB can be defined by age, mining occupation, silicosis status, and HIV infection with predicted rates of 100/1000 person-years. TB screening programmes should take special cognisance of high risk groups of gold miners.

Adolescent↗
PubMed1997

Attendance versus compliance with tuberculosis treatment in an occupational setting--a pilot study.

AIM: To determine the prevalence of non-compliance with tuberculosis treatment at Freegold Mines. OBJECTIVES: 1. To establish the rates of attendance and collection of anti-tuberculosis drugs. 2. To determine prevalence of non-compliance by means of urine tests. DESIGN: A cross-sectional study conducted over 2 weeks at mine medical stations. METHOD: Urine samples were collected from tuberculosis patients 3 hours after drug ingestion. Non-compliance was established by testing these samples for rifampicin and/or isoniazid (INH) metabolites. Non-compliance was defined as a negative urine test result for these drugs in participants whose treatment regimens included one or both. Daily attendance and collection of drugs statistics are recorded in the medical station tuberculosis register. The patient rate of adherence was calculated as the observed number of days on which medication had been collected over the expected treatment days in a given period. RESULTS: Urine test results showed an overall prevalence of non-compliance of 14.6 +/- 3.3%. The study showed that non-compliance with tuberculosis treatment was underestimated by the surveillance data. The rate of non-adherence with treatment established from the formal surveillance procedure was 0.2%. The poor response rate of patients was found to be a major problem and fewer than 40% per day returned to bring urine specimens. The mean prevalences of non-compliance established by rifampicin and INH tests were 19.5 +/- 5.3% and 9.8 +/- 3.9%, respectively, and these were significantly different (Chi 2 = 7.44; P < 0.05). The proportion of false-positive results for INH and rifampicin urine tests were 21% (11/53) and 35% (17/48), respectively, showing that some patients were taking the wrong treatment. CONCLUSIONS: It is clear that attendance at the clinics does not accurately reflect compliance. Both programme compliance (dispensing of the correct treatment) and patient compliance need to be improved. This has important implications for the new national tuberculosis control policy adopted by the South African government that stresses the importance of directly observed therapy, short-course (DOTS) and a patient-centred approach.

Antibiotics, Antitubercular↗
PubMed1997

Predictors of smoking in a cross section of novice mine workers.

OBJECTIVE: To determine demographic predictors of smoking status amongst novice mine workers. SETTING: Prospective mine workers undergoing fitness examination at the Medical Bureau for Occupational Diseases. DESIGN: Cross sectional study. MAIN OUTCOME MEASURES: Current smoking status. RESULTS: Smoking status is significantly linked to age, race group, nationality and previous employment status. Education is also a predictor of smoking status, but the association is weak. Smoking prevalence in subgroups of novice mine workers varies from less than 10% to nearly 75%. CONCLUSION: Assumptions of very high smoking rates amongst all mine workers are too simplistic. Smoking cannot be regarded globally as a major confounder of occupational exposure and occupational lung disease for all groups of mine workers.

Adolescent↗
PubMed1996

Cancer incidence near municipal solid waste incinerators in Great Britain.

By use of the postcoded database held by the Small Area Health Statistic Unit, cancer incidence of over 14 million people living near 72 municipal solid waste incinerators in Great Britain was examined from 1974-86 (England), 1974-84 (Wales) and 1975-87 (Scotland). Numbers of observed cases were compared with expected numbers calculated from national rates (regionally adjusted) after stratification by a deprivation index based on 1981 census small area statistics. Observed-expected ratios were tested for decline in risk with distance up to 7.5 km. The study was conducted in two stages: the first involved a stratified random sample of 20 incinerators; the second the remaining 52 incinerators. Over the two stages of the study was a statistically significant (P<0.05) decline in risk with distance from incinerators for all cancers combined, stomach, colorectal, liver and lung cancer. Among these cancers in the second stage, the excess from 0 to 1 km ranged from 37% for liver cancer (0.95) excess cases 10(-5) per year to 5% for colorectal cancer. There was evidence of residual confounding near the incinerators, which seems to be a likely explanation of the finding for all cancers, stomach and lung, and also to explain at least part of the excess of liver cancer. For this reason and because of a substantial level of misdiagnosis (mainly secondary tumours) found among registrations and death certificates for liver cancer, further investigation, including histological review of the cases, is to be done to help determine whether or not there is an increase in primary liver cancer in the vicinity of incinerators.

Incidence↗
PubMed1995

Smoking behaviour can be predicted by neighbourhood deprivation measures.

STUDY OBJECTIVE: To assess whether small area measures of socioeconomic deprivation predict variation in individual smoking behaviour. To examine the adequacy of an individual level statistical model for the analysis of data on groups of individuals who live in the same geographical area. DESIGN: Individual level and two level logistic regression analysis of data on individual smoking from a regional health survey, and neighbourhood deprivation scores for 1991 census wards calculated from 1991 census data. SETTING: The North West Thames Regional Health Authority area. PARTICIPANTS: Random sample of 8,251 adults in North West Thames Regions. MAIN RESULTS: There was a highly significant association between being a smoker and the neighbourhood deprivation score of the area of residence. With the two level model, after allowing for age and sex, the estimated odds ratio of being a smoker for an individual in the highest quintile of deprivation compared with someone in the lowest quintile was 1.52 (95% confidence interval 1.33, 1.74). Results obtained using the individual level model were similar. Variation between wards accounted for around 6% of the total variation in smoking behaviour after neighbourhood deprivation of the ward had been taken into account. Deprivation of the area of residence remained a significant predictor of smoking status even after the socioeconomic group of the individual has been taken into account. CONCLUSIONS: Neighbourhood deprivation of the area of residence is a predictor of smoking status of individuals. In this example the two level model was reasonably well approximated by the individual level model.

Adult↗
PubMed1995

A standardisation approach to the control of socioeconomic confounding in small area studies of environment and health.

OBJECTIVE: To assess how effectively a routine adjustment can be made for socio-economic confounding in small area studies of environment and health using indirect standardisation and small area deprivation indices, including analysis of the appropriate size of population unit on which to base the deprivation index and the importance of region and urban/rural status as axes of stratification. METHODS: Standardised morbidity ratios were calculated for cancers in Great Britain for 1981 and standardised mortality ratios for all cause mortality in Great Britain between 1982 and 1985. Deprivation indices were calculated for enumeration districts and wards from 1981 small area census statistics. Cancers and deaths were allocated to enumeration districts via their postcode. Standardised morbidity and mortality ratios were calculated by quintile of enumeration district according to the deprivation index. Standardised mortality ratios were further analysed by deprivation of ward, region, and urban/rural status. RESULTS: Strong relationships were found between all cause mortality and the incidence of selected cancers and deprivation quintile-there was up to a twofold difference in lung cancer incidence between the highest and lowest quintile. The deprivation index can be used to measure gradients of deprivation according to the distance from industrial sites. The deprivation index for enumeration districts showed similar discrimination of mortality as the index forwards. There is some interaction between deprivation and region in their effect on the standardised mortality ratios, leading to a small bias in the estimation of expected numbers if this is not taken into account. The relationship between deprivation, urban/rural status, and mortality is complex and confounded by region, but mortality tends to be higher in urban than in rural areas within quintiles of deprivation. DISCUSSION: Whether calculated for enumeration districts or wards, the main problems in the interpretation of the deprivation index may be its limited correlation with the risk factors of interest and its concentration on present rather than past socioeconomic status. Indirect standardisation based on stratification for deprivation and other variable involves a trade off between bias and precision in determining the fineness and the number of axes of stratification. Some bias may occur due to interaction between region and deprivation and the effects of urban/rural status. Complementary approaches including modeling and proportional mortality or morbidity analyses may be needed and the possibility of residual socioeconomic confounding must always be considered. CONCLUSION: There is potential for important socioeconomic confounding in small area studies of environmental pollution and health where the health outcome under examination has a strong relationship to socioeconomic status and where the putative excess risk due to pollution may be small. One method of controlling for confounding is to use an ecological measurement of deprivation in small areas, and to adjust for deprivation by indirect standardisation. However, residual socioeconomic confounding can be expected, which may seriously complicate the interpretation of small area studies.

Adolescent↗