Associated factors and global adherence of cervical cancer screening in 2019: a systematic analysis and modelling study

Background: Cervical cancer screening is vital for its prevention. Adherence is a crucial indicator that implies the individual willingness to take cervical cancer screening. We aimed to estimate the global and regional adherence rates of cervical cancer screening in 2019 and identify its associated factors among general women. Method: We searched studies in PubMed, Web of Science, Embase, China National Knowledge Infrastructure, Wanfang Database, ProQuest theses database and Google Web, without a lower time limit and until 23 June, 2021. Survey studies were considered eligible if they investigated cervical cancer screening adherence among general women, with data on sample size, the number of adherent subjects, and/or adherence rate. Random-effects were used to pool the odds ratios (ORs) of associated factors of adherence. Using modelling analysis, we estimated 2019 overall and age-specific adherence rates at the global and regional levels in women aged 20-69 years. Results: Eight thousand two hundred ninety records were identified, and 153 articles were included. Being married (vs not married: OR, 1.34; 95% confidence interval [CI]: 1.23-1.46), higher educational attainment (higher than high school vs less than high school: OR, 1.44; 95% CI: 1.35-1.53), having healthcare (OR, 1.64; 95% CI: 1.43-1.88), former smoking (OR, 1.20; 95% CI: 1.07-1.34), physical activity (OR, 1.19; 95% CI: 1.05-1.36), parity (OR, 1.07; 95% CI: 1.01-1.12), and chronic disease (OR, 1.17; 95% CI: 1.04-1.32) were associated with better adherence, whereas obesity (vs normal: OR, 0.85; 95% CI: 0.74-0.97) and current smoking (vs former/never: OR, 0.64; 95% CI: 0.54-0.76) were associated with worse adherence. In 2019, the adherence was at 33.66% (95% CI: 23.34-39.30%) worldwide, and was higher in high-income countries (HICs) (75.66, 95% CI: 66.74-82.81%) than in low and middle-income countries (LMICs) (24.91, 95% CI: 14.30-30.24%). It varied across regions, the highest in the European region (65.36, 95% CI: 55.40-74.19%), but the lowest in the African region (5.28, 95% CI: 3.43-8.03%). Conclusions: Cervical cancer screening adherence remained low globally, exhibiting geographical discrepancy with HICs higher than LMICs. Further implementations of screening programs should comprehensively consider the local economy, social benefits, and demographic structure to adapt delivery for vulnerable or underserved women to boost screening adherence.