The mix of contraceptive methods that women may use is simulated in the model based on demographic characteristics and age. Women may switch between methods in the model for reasons such as side-effects or method failure.
Method of contraception is based on data from the DHS (variable v312), conditional on whether a woman is spacing or limiting. We estimated age and time trends based on DHS data for 1,409,587 women from 254 surveys in 74 countries.
We model the use of 10 contraception methods: Pill, IUD, Injections, Condom, Female sterilization, Male sterilization, Periodic abstinence, Withdrawal, Implants, Other. Due to the small number of responses for certain methods we combined ‘Diaphragm’ with ‘Condom’, and ‘Prolonged abstinence’ with ‘Periodic abstinence’. We re-coded other methods not listed above as ‘Other’. Here we plot time trends in method mix for spacing and limiting by income group, based on DHS data. (Note: No high income countries are available in the DHS.)
We estimated hierarchical logistic regression models for each method, stratified by subgroup. Separate models were estimated for spacing and limiting. The predicted probabilities of each method were re-normalized to ensure that the probabilities sum to 1.0. We used upper middle income priors for high income countries due to lack of DHS data in high income countries.