This study showed insufficient cervical cancer screening utilization in Iran. About half of the recommended target population in the national guideline (52.1%) have reported having had at least one Pap test in their lifetime. Having 6–12 years of schooling, and being covered under primary or complementary health insurance plans were significantly associated with higher participation. The highest screening uptake rate was obtained in Isfahan and the lowest in Sistan and Baluchestan. Moreover, this study has added to the small body of literature which has assessed socio-economic equity in cervical cancer screening in Iran. A pro-poor bias was observed across the country in cervical cancer screening participation.
In general, the cervical cancer screening participation rate in Iran was low in comparison with most developed countries. In the United States of America 85.5% of women aged 21–64, in Spain 72% of women aged 25–65, and in Australia 61% of women aged 20–69 had undergone cervical cancer screening in the past 3 years [19,20,21]. However, within developing countries, Iran holds an intermediate position. The prevalence of having ever been screened for cervical cancer was 19% in Jordan (in women aged 20–49), 46.3% in Thailand (in women 30 years and above), and 87.1% in Brazil (in women aged 25–64) [22,23,24,25]. Lack of an organized population-based screening program may underlie the lower participation rate in Iran. The opportunistic approach which has been in place for more than three decades, has failed to reach many at-risk women in the population.
The proportion screened was slightly higher for the 40–49-year age group. Nonetheless, age was insignificantly associated with cervical cancer screening participation in the logistic regression analysis. Although this finding was aligned with results published from England and Thailand, but it was inconsistent with those reported in Jordan, and Brazil [22,23,24, 26]. Probably Iranian women in their thirties, forties, and fifties tend to be equally informed about cervical cancer, and there are no differences in their Pap screening behavior.
As expected, married women were most likely to have undergone cervical screening, which was in line with previous evidence [19, 20, 23]. Married women tend to attend healthcare facilities more often for maternal and child health care which can expose them to awareness activities about cervical cancer screening. Yet, there are several possible explanations for the very low participation rate in single women shown in this study. Sexual relationship outside marriage is not culturally accepted in Iran. Therefore, single women are commonly less sexually active. And, those who are sexually active may not accept to be screened with a test which is perceived to be for married women, in fear of the potential social stigma. Moreover, the participation rate in single women may also be more affected by under-reporting due to embarrassment in admitting to have been screened for cervical cancer.
With regards to education level, women with no education were least likely to participate in cervical cancer screening program. Higher education was associated with higher participation only until about 12 years of schooling. This finding is consistent with other study results conducted in Iran, but not with those of other countries [14, 19, 20]. The fact that illiteracy was associated with lower level of participation, reflects the existing problems in effective communication. Problems which result in difficulties in understanding the benefits of screening in women with no education.
The present study determined that employment was a negative predictor for cervical cancer screening practice, when compared to unemployment. While, participation rates in retired women and university students did not differ significantly from that of unemployed women. This finding contradicts similar studies in other countries, yet validates the results of studies conducted in Iran [14, 27, 28]. Having less free time, might be the possible rationalization for this unexpected finding among working women. Furthermore, hours of operation in most healthcare facilities delivering cervical screening services coincide with usual working hours and may act as a barrier for employed women.
In parallel with other studies, women with health insurance coverage were more likely to have undergone cervical screening [20, 29, 30]. Health insurance plans can increase health service utilization by reducing out-of-pocket expenditures and alleviating potential financial barrier to the service uptake. In Iran, the basic health insurance plans cover most cervical cytology screening costs, and complementary plans provide a full coverage of the service fees.
Uptake rates in urban and rural settlements showed no statistically significant difference in the multivariate analysis. Controversial results have been reported in the literature. In Thailand, rural populations have reported greater participation in cervical cancer screening program. Whereas in Spain and Jordan, the prevalence of cervical cancer screening was higher in urban settings. In Canada, participation rates were not significantly different for urban and rural residents [20, 22, 23, 31]. This finding points to the considerable success of the Iranian primary health care approach in delivering health services to remote and rural areas of the country in the past three decades .
This study also revealed evidence of disparities in cervical cancer screening participation across socio-economic groups in Iran. Contradicting with findings in most countries, women with higher socio-economic status had shown lower participation in cervical cancer screening program [19, 22]. However, pro-poor inequality was shown in out-patient healthcare utilization in multiple studies in Iran [33, 34]. Perhaps this finding could be explained by the nature of the health care system. In Iran, the primary health care facilities are all publicly owned. Women in lower socio-economic levels routinely visit these facilities for healthcare services such as maternal and child care, which provides opportunities for communication about cervical cancer screening. Whereas, women in higher socio-economic levels often see specialists directly and based on their health complaints. Therefore, preventive services are substantially underutilized by this group .
The major strength of the study is the use of a large nationally representative sample of rural and urban Iranian women, containing different socio-economic levels, that allowed more confident inferences about the population. However, there are some potential limitations as well. First, the cross-sectional design of the study has limited the ability to draw conclusions about causal relationships. Second, the data on the history of having ever undergone cervical cytology were self-reported, and therefore may be susceptible to recall and social desirability biases. Lastly, by evaluating secondary data sources in this study, the assessment of all factors associated with cervical cancer screening participation was not possible.