Background Sierra Leone has one of the world's highest rates of maternal mortality. Preventing unintended pregnancies reduces the burden of maternal morbidity and mortality. Unfortunately, 25% of reproductive-age women do not have access to modern contraceptive services, and the proportion of demand met for modern contraception remains low at 46% in Sierra Leone. Rural Sierra Leonean women use modern contraception less frequently than urban women. This study aimed to quantify the rural-urban disparity in modern contraceptive use among Sierra Leonean women of reproductive age and to identify factors that explain it. Method Data from 2019 Sierra Leone demographic health survey was used. Participants were sexually active women aged 15 to 49 (n=13,975). Modern contraceptive use was the outcome variable. Explanatory variables were grouped into materialistic, behavioral/cultural, and psychosocial theoretical perspectives. Descriptive statistics, intermediary analysis, and blinder Oaxaca decomposition analysis were used to summarize and identify the factors that explain inequalities in modern contraceptive use between rural and urban women. Data were analyzed using Stata version 14.0. Results There was a rural-urban disparity in modern contraceptive use of 18 percentage points favoring urban women. The exposure variables explained 68% of this disparity. Education (76%), marital status (39%), hearing about family planning on the radio (16%), age of respondent (13%), problems with distance to a healthcare facility (12%), and problems getting permission to seek treatment (9%) made a significant contribution to the explanation of the modern contraceptive use disparity between urban and rural women. Conclusions There was a large rural-urban disparity in modern contraceptive use in Sierra Leone that favoured urban women. Material, behavior/cultural, psychosocial, and demographic explanatory factors jointly explained 68% of the disparity in modern contraceptive utilization between rural and urban women. To close the rural-urban disparity in modern contraceptive use, policy makers must address inequities in education, mass media (radio), and healthcare access. Rural women should be empowered to have the autonomy to access healthcare. Educating men about modern contraceptives and involving them in contraceptive programs can increase rural women's ability to get permission to seek care hence increasing modern contraceptive utilization and consequently bridging the rural-urban gap.

The authors have declared no competing interest.

The authors received no specific funding for this work.

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The ICF Institutional Review Board reviewed and approved the procedures and questionnaires for the Sierra Leone Demographic Health Survey of 2019. Sierra Leone IRB reviewed the protocols for the Survey.

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The data set used is openly available upon permission from the MEASURE DHS website (URL: https://www.dhsprogram.com/data/available-datasets.cfm). However, authors are not authorized to share this data set with the public, but anyone interested in the data set can seek it with written permission from the MEASURE DHS website (URL: https://www.dhsprogram.com/data/available-datasets.cfm).

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