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. 2017 Aug 15:5:186.
doi: 10.3389/fpubh.2017.00186. eCollection 2017.

A Latent Markov Model with Covariates to Study Unobserved Heterogeneity among Fertility Patterns of Couples Employing Natural Family Planning Methods

Fulvia Pennoni  1 , Michele Barbato  2 , Serena Del Zoppo  2
Affiliations

A Latent Markov Model with Covariates to Study Unobserved Heterogeneity among Fertility Patterns of Couples Employing Natural Family Planning Methods

Fulvia Pennoni et al. Front Public Health. .

Abstract

Purpose: We use the historical data from the European Study of Daily Fecundability and we develop an algorithm to determine the fertile window in a woman's cycle according to the rules of the C.A.Me.N. symptothermal method proposed by the Centro Ambrosiano Metodi Naturali. Our aim is to identify variables acting on the probability of conception by considering the fertile window and factors that cannot be explained by employing the observed covariates of individuals and couples.

Methods: We adopt the latent Markov model with covariates tailored for data collected at times when a latent process detects the dependence across fertile periods of each woman's cycle. We consider measurement errors, transitions between conception and non-conception, and the prediction of conception rate over the fertile windows.

Conclusion: We find that the conception pattern is mainly related to sexual intercourse behavior during the fertile window and to previous pregnancies. For the cohort under study, we predict a steep decline in the average conception rate across fertile windows.

Keywords: expectation–maximization algorithm; latent stochastic process; natural family planning methods; predictive probabilities; state dependence.

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Figures

Figure 1
Figure 1
Average predicted probabilities of conception (state 2) in accordance with the LM model estimated for an increasing number of fertile windows.
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References

    1. Bartolucci F, Farcomeni A, Pennoni F. Latent Markov Models for Longitudinal Data. Boca Raton: Chapman and Hall/CRC Press; (2013).
    1. Lazarsfeld PF, Henry NW. Latent Structure Analysis. Boston: Houghton Mifflin; (1968).
    1. Lazarsfeld PF. The logical and mathematical foundation of latent structure analysis. In: Stouffer SA, Guttman L, Schuman EA, editors. Measurement and Prediction. New York: Princeton University Press; (1950).
    1. Pennoni F. Issues on the Estimation of Latent Variable and Latent Class Models. Saarbücken: Scholars’ Press; (2014).
    1. Bartolucci F, Farcomeni A, Pennoni F. Latent Markov models: a review of a general framework for the analysis of longitudinal data with covariates (with discussion). TEST (2014) 23:433–65.10.1007/s11749-014-0381-7 - DOI

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