The study examined the inequalities in modern contraceptive use among women in Sierra Leone between 2008 and 2019. The study found that the prevalence of modern contraceptive use among women in Sierra Leone has increased significantly from 6.7% in 2008 to 20.9% in 2019. Overall, the results show that Sierra Leone has made progress in reducing inequalities in modern contraceptive use among women across various dimensions from 2008 to 2019. The decreasing trends in disparity, PAF, PAR, and ratios indicate that the gaps in contraceptive use due to economic status, education, place of residence, and region are narrowing. This implies that interventions and policies implemented during this period may have effectively addressed these inequalities.

Our study found that the prevalence of modern contraceptive use among women in Sierra Leone has increased significantly from 6.7% in 2008 to 20.9% in 2019. Our finding prevalence is similar to the 18.1% reported among married or in-union women in Sierra Leone[12]. However, this rate remains notably lower than the African regional average of approximately 50% [2]. Sierra Leone has faced significant socio-economic challenges, including the aftermath of a devastating civil war, which has hindered the development of healthcare infrastructure and access to essential services [23]. Limited availability of family planning resources, particularly in rural areas, can restrict women's access to modern contraceptives [7]. Additionally, cultural beliefs and stigma surrounding contraceptive use may further impede acceptance and utilization, particularly in more conservative communities [24]. Also, the effectiveness of family planning programs and policies in Sierra Leone may not have reached the same level of implementation and impact as seen in other African countries, where comprehensive strategies have been employed to enhance contraceptive access and education [8].

The disparity in modern contraceptive use by age in Sierra Leone increased from 2008 to 2019, specific initiatives, such as the National Family Planning Program, have aimed to improve access to contraceptive services for women, yet there remains a gap in targeted interventions for younger populations [7]. Factors contributing to persistent inequalities include cultural norms that prioritize reproductive roles for older women, limited access to youth-friendly services, and a lack of comprehensive education about contraceptive options for younger women [30]. Evidence from neighboring countries like Ghana and Nigeria shows that inclusive programs addressing the unique needs of all age groups can enhance contraceptive uptake [31]. For instance, Ghana’s community-based outreach strategies have successfully engaged both younger and older women, highlighting the importance of tailored interventions [32]. Further research is essential to explore the specific barriers faced by younger women in Sierra Leone, ensuring that family planning programs are effectively inclusive and responsive to the needs of all age groups.

The decrease in disparity in modern contraceptive use among women in Sierra Leone, particularly concerning education and economic status, indicates progress in making contraception more accessible across various backgrounds. This finding is consistent with the previous studies [33,34,35]. Specific initiatives, such as the Free Health Care Initiative and the National Family Planning Program, have aimed to provide subsidized or free contraceptives, particularly benefiting low-income women [24, 25]. Additionally, campaigns like Family Planning for All have focused on educating women in low-income communities about the benefits and availability of modern contraception through workshops and community leader engagement [9]. The establishment of more clinics and pharmacies in underserved areas has also improved access [36]. However, persistent inequalities remain, largely due to cultural norms that prioritize traditional reproductive roles, limited health literacy, and the socio-economic barriers that continue to affect low-income women disproportionately [37]. Evidence from low-and middle-income countries comprehensive family planning approach and targeted outreach programs, demonstrates the importance of inclusive strategies that address the unique needs of both low-income and educated women [38]. To further enhance contraceptive uptake, it is crucial to continue addressing cultural barriers and promote gender equality, ensuring that all women can make informed choices about their reproductive health in Sierra Leone.

The rise and subsequent fall of place of residence inequality in modern contraceptive use among women in Sierra Leone from 2008 to 2019 reflects significant changes in access to family planning services. Between 2008 and 2013, limited availability of these services in rural areas likely perpetuated a consistent disparity, as many rural women faced barriers such as distance to health facilities, lack of transportation, and insufficient healthcare infrastructure [39]. However, the period from 2013 to 2019 may have seen a concerted effort to address these issues, with initiatives such as the expansion of mobile clinics, training programs for rural health workers, and community awareness campaigns that effectively increased access to contraceptives for rural populations [24]. Despite these advancements, persistent inequalities can still be attributed to factors such as cultural norms that discourage contraceptive use, limited education about reproductive health, and economic constraints that disproportionately affect rural women [40]. For instance, similar trends in neighboring countries like Liberia and Ghana highlight the importance of targeted interventions in rural areas; Liberia's community-based distribution programs have successfully improved contraceptive access [41], while Ghana's integration of family planning into primary healthcare has reduced disparities [31]. These examples underscore the need for continued focus on addressing the unique challenges faced by rural women in Sierra Leone, ensuring that family planning services are not only accessible but also culturally accepted and economically feasible.

The decrease in provincial disparity in modern contraceptive use among women in Sierra Leone from 2008 to 2019 indicates progress toward more equitable access to family planning services. Engaging local communities has been crucial in promoting awareness and education about contraceptive use; initiatives that involve community leaders, women’s groups, and religious figures have been effective in addressing cultural barriers and fostering acceptance of family planning [24]. However, persistent inequalities can still be traced to underlying factors such as socio-economic disparities, varying levels of health literacy, and infrastructural challenges [7]. For instance, while investments in improving roads and transportation networks have facilitated access to clinics in some areas, remote regions may still lack adequate healthcare facilities and trained personnel, limiting service availability [42]. Evidence from similar countries, such as Ethiopia, Rwanda, and Malawi have successfully reduced regional disparities through community health worker programs and targeted outreach, underscores the importance of tailored interventions that consider local contexts [43]. To sustain the momentum in reducing provincial disparities in Sierra Leone, it is essential to continue addressing these systemic barriers while ensuring that all communities, particularly those in remote areas, benefit from improved access to comprehensive family planning services.

Our study on modern contraceptive use in Sierra Leone (2008–2019) offers valuable insights for policymakers and practitioners working on family planning programs. The significant rise in modern contraceptive use suggests that existing policies and programs have been effective in raising awareness and improving access. This is a positive foundation for further progress. The decline in inequalities based on residence, and province indicates a broader reach of family planning services. This suggests a successful approach to reaching diverse populations. Although reduced, economic status remains a key factor in contraceptive access. Policies promoting women's economic empowerment and poverty reduction could have a significant impact. This could involve microfinance initiatives, vocational training, or childcare support. While educational gaps are narrowing, continued efforts to increase girls' education can have a long-term impact. This could involve scholarships, addressing gender biases, or improving rural education access. The study highlights the importance of acknowledging remaining provincial disparities. Policies and programs should be adapted to address the specific needs of lagging provinces. This might involve campaigns or clinics, culturally sensitive information campaigns, or training local healthcare providers. Continued monitoring of contraceptive use trends across different demographics is crucial. This allows policymakers to identify emerging inequalities and adapt programs accordingly. Evaluating the effectiveness of existing interventions is essential. Understanding what works best can help optimise resource allocation and program design. By implementing these policy and practice changes, Sierra Leone can ensure equitable access to modern contraception for all women, regardless of age, economic status, education level, residence, or province.

The SLDHS is a nationally representative survey that provides data from a large and diverse sample of women in Sierra Leone. This ensures the study findings can be confidently generalised to the broader population. The SLDHS collects data on a wide range of variables related to contraception and reproductive health, including demographics, socioeconomic status, and contraceptive use. This allows for a comprehensive analysis of how different factors influence contraceptive use inequalities. WHO Heat software is a powerful tool for visualising complex data sets. It can be used to create clear and informative charts that effectively communicate the trends and inequalities in modern contraceptive use across different groups of women in Sierra Leone. The limitation of using SLDHS and WHO Heat software is that SLDHS provides data at a single point. While it can show trends over time (2008–2019), it cannot definitively establish cause-and-effect relationships between factors and contraceptive use. Like any survey, the SLDHS is susceptible to reporting bias. Women might be hesitant to answer truthfully about sensitive topics like contraception. The SLDHS and WHO Heat software primarily focus on quantitative data. They don't capture the lived experiences and reasons behind contraceptive use inequalities.