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Biomedical subjects

S Radhakrishna

Publications and source records attributed to S Radhakrishna.

At least 37 records · Page 2Linked to original sources
PubMed1999

The 1997 Nationwide Tuberculosis Prevalence Survey in the Philippines.

SETTING: The Philippines is a developing country where tuberculosis (TB) remains a significant public health problem. OBJECTIVE: To determine the prevalence of TB as a basis for setting the targets of the National Tuberculosis Control Program. STUDY POPULATION AND METHODS: A multi-stage cluster survey of a random sample of 21960 subjects from 36 clusters nationwide was undertaken from 2 April to 31 July 1997. BCG scar verification and tuberculin testing was performed for subjects aged 2 months and over, and chest radiography screening was done on subjects 10 years and older. Sputum samples were collected from individuals who were initially assessed to have abnormal chest radiographs to determine the prevalence of bacillary tuberculosis. Acid-fast smear by modified Kinyoun's technique and culture on Löwenstein Jensen were done to demonstrate Mycobacterium tuberculosis. RESULTS: The prevalence of active pulmonary TB was 42/1000 population. The prevalence of culture-positive and smear-positive cases was 8.1 and 3.1/1000, respectively. The prevalence was similar in urban and rural areas. CONCLUSION: Morbidity from TB remains high. Allowing for methodological differences from the survey in 1981-1983, the prevalence of active pulmonary TB was unchanged. There was only a minimal decrease, of 37% for smear-positive cases and 25% for culture-positive cases, in the 14-year interval.

Adolescent↗
PubMed1999

Lot quality assurance sampling for monitoring immunization coverage in Madras City.

OBJECTIVE: To explore the usefulness of Lot Quality Assurance Sampling (LQAS) to identify divisions in a city that had immunization coverage levels of 80% for any of the four EPI vaccines. METHODS: Only 43 divisions were considered for the study, the stratification factor being the death rate. The hypothesis that 80% coverage is 'unacceptable' was stipulated. Critical value (the number of unimmunized children) was chosen as 3. A simple random sample of 36 children in the age-group 12-23 months was taken from each selected division. Since sampling frames of children were not available, a simple random sample of 36 households was selected. Immunization status of each child was assessed by interviewing the child's mother/guardian. If the number of unimmunized children exceeded 3, then the division was regarded having coverage level 80% and rejected. RESULTS: The coverage was classified as unacceptable(i. e., below 80%) in 19 divisions for Polio and DPT vaccines, in 26 divisions for Measles vaccine and in 4 divisions for BCG vaccine. The average time spent for undertaking the LQAS survey was 6 man-days per division. CONCLUSION: This study demonstrated the utility of the LQAS technique in identifying 'unsatisfactory' pockets in Madras City, when the overall coverage was satisfactory. The technique will have greater application with an increase in the number of large units (cities/districts) having an overall coverage of 90% or more.

Health Care Surveys↗
PubMed1995

A concurrent comparison of a WHO-recommended 30-cluster survey and a modified version of it under Indian conditions in the estimation of immunization coverages.

A concurrent comparison of the WHO 30-cluster sample survey method for estimating immunization coverages (DPT, Polio, BCG, Measles) and an Indian modification of (GOI) was undertaken in five districts in South India. The essential difference between the two methods is the manner in which the first household is selected in the chosen clusters. With the WHO method, it is chosen clusters. With the WHO method, it is chosen at random, whereas with the GOI method it is often close to the village centre. Estimates with the required degree of precision, i.e., 95% confidence limits of +/- 10 percentage points, were provided in 18 (90%) of 20 instances by the WHO method and in 19 (95%) by the GOI method, findings which are in accordance with expectation. The estimated coverages were, however, higher by the GOI method than by the WHO method in two districts, lower in one district, and in the remaining two districts there was no clear pattern. On the average, there was a suggestion that the GOI method yielded slightly higher coverages, but the differences were not statistically significant.

Health Surveys↗
PubMed1995

Randomised controlled field trial of two antenatal care packages in rural south India.

A randomised community intervention trial was undertaken in 12 subcentres in Karur health unit district, Tamil Nadu, to compare the efficacy of two antenatal care packages. A newly recommended 'high-risk' strategy package and a uniform package recommended by the Tamil Nadu Government were each implemented in 4 randomly selected subcentres by the study team, and the latter was also delivered by routine health services in the 4 remaining subcentres. Analyses were based on 294 pregnant women on the high-risk package (HR), 242 on the Tamil Nadu Government (TNG) package and 335 women in the control series. The HR package reduced the differences between the high-risk women and the others in mean haemoglobin and the percentages with preventable neonatal morbidity and low birth weight, and consequently the overall outcome was better in the HR series than in the TNG series. Finally, the results with the TNG package were better when it was implemented by the study team than by the routine health services, in terms of preventable maternal morbidity and preventable perinatal morbidity, but there was no impact on birth weight.

Birth Weight↗
PubMed1993

Estimation of immunisation coverages in children by WHO 30-cluster survey.

A WHO 30-cluster survey for estimating immunisation coverages in infancy was undertaken in each of 5 districts in Tamil Nadu, strictly according to the specifications laid out in the WHO manual. The main aim was to examine whether the technique would provide estimates with the required degree of precision under Indian conditions. Of 60 sample survey estimates, 57 had the targeted degree of precision (i.e., 95% confidence limits of +/- 10 percentage points), which is in excellent agreement with expectation. The proportions of infants on whom immunisation was initiated, were very high for DPT vaccine (88-99%) and polio vaccine (85-99%); however, of those who had received the first dose, 23-39 per cent did not complete the 3-dose schedule. Estimated coverage with measles vaccine ranged from 15 to 54 per cent, while BCG coverage ranged from 53 to 97 per cent. Better health education regarding the need and correct age for immunisation, and more effective motivation at the time of administration of the first dose of DPT/polio vaccine, are recommended.

Diphtheria-Tetanus-Pertussis Vaccine↗
PubMed1992

Confidence intervals in medical research.

The utility of confidence intervals in a wide variety of situations in the medical field is re-emphasized, with examples drawn from controlled clinical trials, disease control programmes, vaccine trials and laboratory studies. It is shown that the confidence interval approach is more informative than a mere test of statistical significance, and should therefore be employed as an useful adjuvant. Since proportions are widely quoted in medical literature and as the determination of the exact confidence limits for a binomial proportion is iterative and time-consuming, an assessment is made of 15 published methods which provide approximate confidence limits; the 'Square root transformation' method is recommended since it is accurate and the computation of limits is relatively easy. In the case of a difference between two proportions, the usual method may be employed if sample sizes exceed 75; for smaller sample sizes (even for sizes of 5), the Jeffreys-Perks method is very satisfactory and is therefore recommended.

Confidence Intervals↗
PubMed1991

Some indices pertaining to the leprosy control programme in Tamil Nadu, based on data from a random sample of fourteen government control units.

From a random sample of 14 Government Leprosy Control Units in Tamil Nadu, information on the profile of the newly-diagnosed leprosy patients and some important aspects of the control programme in 1978-81 was collected when monotherapy with dapsone was the practice. Among the new patients, 55 per cent were males, 24 per cent were children, 6 per cent had lepromatous leprosy and 9 per cent had a deformity. About 65 per cent were detected by active case-finding methods and 25 per cent were voluntary referrals. Of the total diagnosed patients, only 68 per cent started treatment; further, of these, about 40 per cent collected drugs for at least 6 months in the first year of treatment. The average attendance at the clinic was 34 per cent of the due attendance. Coverage in the annual examination of family contacts was 57 per cent. During the 4 yr period, about 70 per cent of the villages had population surveys with a coverage of 75 per cent or more. The introduction of multi-drug therapy has provided a new impetus to the programme and therefore a similar study is called for to provide valuable information about the extent of improvement in completion rates and overall impact.

Adolescent↗
PubMed1987

Hookworm infection in a rural community in south India and its association with haemoglobin levels.

Faecal samples were obtained from 1113 persons living in a rural area in South India, and the hookworm ova load (Necator americanus) was determined using Kato's thick smear method. Evidence of hookworm infection was present in 92%, 77% having a count of under 100 epg, 11% a count of 1000 to 1999 epg, and 4% having counts between 2000 and 12,000 epg. Females had significantly higher ova counts than males on the average, but age did not appear to have any effect. Haemoglobin was also estimated: 80% of adult males, 87% of adult females and 90% of children were anaemic. There was a significant negative association between ova load and haemoglobin level, and the decrease in haemoglobin for a doubling of the ova load was estimated by regression analysis to be 0.18, 0.29 and 0.16 g/dl in adult males, adult females and children, respectively. There was nearly perfect agreement in the ranking of 10 clusters by mean ova count and mean haemoglobin level or percentage with anaemia.

Adolescent↗
PubMed1987

Association between regularity in dapsone (DDS) treatment and development of deformity.

The existence of an association between regularity in dapsone intake and the development of deformity was investigated in 5746 leprosy patients under treatment in South India. The incidence of deformity, year by year over a 5-year period, increased significantly with increasing levels of drug collection. The excess incidence in "more regular" patients was significant at all ages and in both sexes in nonlepromatous (N) cases. The same was true in intermediate (N?L) cases except in patients under 15 years of age. The evidence in lepromatous (L) cases was not so consistent. Independent confirmation of the presence of the association was sought through a matched case-control type of analysis with 140 N, 48 N?L, and 81 L cases, matching being undertaken with respect to sex, age, type of leprosy, year of starting treatment, and observation period. This showed that the mean regularity in cases (deformed patients) before the development of deformity was significantly higher than the mean regularity in the corresponding matched controls, the differences being particularly large among the N and N?L types. These findings raise the possibility of a causal link between regular dapsone intake and the development of deformity.

Adolescent↗
PubMed1984

A novel system to obtain addresses of out-patients--assessment in routine clinic practice in Madras, S. India.

A novel method of obtaining accurate home addresses from out-patients was introduced as a routine procedure in 6 chest clinics of Madras City, following highly satisfactory results under study conditions. In this method, the patient is given a card (the address card), and asked to get his exact address entered on it by any knowledgeable person of his choice such as a landlord or neighbour. An assessment of the system was undertaken after it had been in operation for about 8 months. A complete and legible address was available for 82% of 3956 patients, the range in the 6 clinics being 74% to 91%. The main causes for failure were: not giving address card to patient (7%), patient not reattending the clinic (6%), and patient reattending but not returning the address card (3%). Corrective measures have now been introduced, and a re-assessment will be undertaken in due course.

Ambulatory Care Facilities↗