Browsing by Author "B.N. Bhattacharya"

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An adjustment of a selection bias in postpartum amenorrhea from follow-up studies
(1979) S.N. Singh; B.N. Bhattacharya; R.C. Yadava
In a prospective study in which females giving birth in a specified small interval of time are followed to obtain the distribution of the duration of postpartum amenorrhea (PPA), the observed distribution involves a selection bias because of an overrepresentation of smaller PPA. In this article, the nature of this selection bias is investigated and an analytical procedure is outlined to adjust the observed distribution of PPA in order to obtain the true distribution. The proposed technique is illustrated with one set of observed data. © 1979, Taylor & Francis Group, LLC.
An extension of a parity-dependent model for number of births and estimation of fecundability
(1984) B.N. Bhattacharya; D.C. Nath
This paper presents a probability distribution describing the variation in the number of births in a human population during a given period since marriage, assuming fertility parameters to be parity dependent. A procedure to obtain maximum likelihood estimates of the parameters is outlined. Its applications are illustrated with observed and simulated data. © 1984.
Distribution of time of first birth in presence of social customs regulating physical separation and coital frequency
(Elsevier Inc., 1996) S. Mukherjee; B.N. Bhattacharya; K.K. Singh
The interval between marriage and the first birth in India, particularly in rural areas, is much longer than what is observed in western countries. In eastern Uttar Pradesh, the mean interval is observed to be even longer, possibly due to traditional customs such as the female partner's visits to her parents in the early years of marriage and the smaller chance of coition because of the observance of rigid intercourse taboos. Thus the models to explain the length of the interval of marriage to first birth proposed by Western demographers, which assume that the period of cohabitation between marriage and first birth is uninterrupted, often do not describe the data satisfactorily when applied to rural India. In this paper a model to describe data on first birth interval is proposed that takes account of the distributions of timing and periods of physical separation and variation in fecundity with effective marriage duration.; The author refers to literature reviews by Sheps and Menken on studies prior to 1972 and Leridon and Mode for more recent studies of the relationship between first birth and marriage. This study examines the probability distribution of time to first live birth in India and takes into account social customs and taboos that relate to physical separation of spouses and coital regulation. Visits to parents and the period of stay are assumed to interfere with coital frequency in the theoretical model. Data are obtained from the 1987-89 Survey of the Effects of Sociocultural Factors on the Determinants of Fertility in Eastern Uttar Pradesh (rural districts of Varanasi, Ghazipur, and Azamgarh). The sample includes about 350 households and currently married (7 or more years) women aged under 50 years in each religious/caste group for each district. Findings show that the mean duration of cohabitation between return marriage (RM) and the first visit to parents was about 14 months for upper caste Hindus compared to 1-3 months in the other religious/caste groups. The mean duration of stay before the first conception was about 13 months among upper caste Hindus compared to 8-11 months for middle caste Hindus, scheduled castes, and Muslims. Life table estimates are reported for the proportion of women who were still staying with parents during the first visit by months that elapsed since the time of the visit to parents and by age at RM and religion/caste. Life table estimates are given for the proportion of women who had not yet visited parents for the first time by month elapsed since RM and by age of the women. Among upper caste Hindus (Group I), the risk of first conception increased with an increase in age at RM in succeeding years. Among the other religions/castes (Group II), the risk in succeeding years was the same among women aged 14 and 15-16 years. Risk increased among women aged 17-19 years.
Model for first birth interval and some social factors
(1988) B.N. Bhattacharya; C.M. Pandey; K.K. Singh
A probability distribution for describing the time of first live birth is developed which is more suitable for traditional societies where the age at marriage is low. The model takes account of temporary separation between husband and wife just after marriage and indirectly incorporates adolescent sterility and the restriction on sexual union imposed on younger couples. The model is applied to the data collected in the large scale sample survey entitled "Rural Development and Population Growth-A Sample Survey 1978" conducted by Centre of Population Studies, Banaras Hindu University, India. © 1988.
Some models for number of births and estimates of natural age-specific fecundability and sterility for a rural part of Northern India
(1987) B.N. Bhattacharya; K.K. Singh; C.M. Pandey
Probability models describing observed distributions of births occuring to women in different segments of the reproductive span are proposed. By applying the models to real data, the values and trends in fecundability and sterility of women in rural areas of northern India are studied. © 1987.