This study assessed the Pap smear uptake trends in Estonia from 2004 until 2020 and the factors associated with the uptake, using data from five waves of a large national cross-sectional population-based survey. The lifetime uptake of Pap smears increased significantly among all age groups, among Estonians and non-Estonians as well as across all education levels. Over the 16-year study period, the uptake gap between age groups and education levels decreased but the inequality between Estonians and non-Estonians increased. Pap smear uptake was influenced by several sociodemographic, socioeconomic, health-related and lifestyle variables, among which education and marital status had the strongest impact on Pap smear uptake.
The present study showed that lifetime Pap smear uptake increased significantly among 25–64-year-old women in Estonia during 2004–2020. Similarly, a Lithuanian study with the same outcome measure showed a lifetime Pap smear uptake increase in 2006–2014 from 73.7 to 86.1% [13]. The increase in Estonia can be explained by a national CC screening program established in 2006, which most likely has positively impacted the CC awareness and therefore urged the Pap smear uptake. On the other hand, it is surprising that in 16 years the organized CC screening program has not had an effect on CC incidence [7]. Furthermore, the stage distribution has shifted towards later stages, and the mortality trend has decreased only slightly [7]. These results reflect the ineffectiveness of the nation-wide screening program and should be investigated further.
Despite the existence of uniform population-based CC screening, the lifetime uptake of Pap smear was significantly lower among non-Estonians. The found inequality is consistent with the results of other international studies [14,15,16,17,18,19], showing that being of foreign origin has had a significant impact on the probability of not attending screenings. While in 2004, ethnicity was not a significant predictor of Pap smear uptake in Estonia [10], we may assume that the inequality has increased, as we observed a more modest increase in Pap smear uptake among non-Estonians than among Estonians. Although most of non-Estonians are originating from the immigration more than 30 years ago, previous studies have shown that non-Estonians have poorer health indicators, poorer self-rated health, shorter life expectancy [20,21,22,23,24], and they are less aware of the screening programs than Estonians [25], making it essential to identify non-Estonians’ barriers to attend, and to facilitate interventions to increase the participation of minority groups.
As consistent with previous studies [13, 15, 18, 26,27,28], being married, living with a partner, and being widowed, separated or divorced, was a stronger predictor for uptake of a Pap smear. Although all target group women in Estonia are invited to CC screening in every 5 years, a Pap smear is also offered to women as part of pre- or post-natal services during their visit to gynaecologist or midwives, which puts women in a sexual relationship in a more favourable position to have an opportunistic Pap smear. Single women may underestimate their risk of CC or other gynaecological conditions and therefore not feel the need for regular check-ups showing the urgent need to improve the organized screening.
The results of this study confirmed the positive effect of education on increased Pap smear uptake, as found in many other studies [14,15,16, 18, 26, 29]. There might be several explanations: well educated individuals have greater awareness about their health risks, more knowledge about health issues, as well as a better access to information and resources for health improvement [30]. Although in this study, lifetime uptake of the Pap smear was found to be significantly higher among women with secondary and higher education, also was observed that the gap between education levels decreased from 2004 to 2020 (Fig. 2D).
Unemployed women were less likely to undergo a Pap smear test, consistent with findings from both a 2004 Estonian study [9] as well as studies from other countries [16,17,18, 27, 28]. Lack of health insurance seems to be the most obvious reason for this finding but according to our study, having health insurance was only associated with the lifetime uptake of Pap smear in univariate analysis and after adjusting to other variables this association disappeared.
Being of normal weight or less was found to be an important positive predictive factor of Pap smear uptake in this study, as has similarly been described in a previous Estonian study [11] and in a meta-analysis [31]. Therefore, particular attention should be paid to overweight as well as to obese women as these groups have a worse prognosis for CC. Possible barriers for testing might be embarrassment in the examination room, negative reactions from healthcare providers, lectures about weight, and inadequate equipment for larger women [32]. To minimize these barriers for overweight women, an alternative could be offering them an HPV self-sampling test. An Estonian pilot study recently showed the feasibility and positive acceptance of HPV self-sampling among long-term CC screening of non-attendees [33] which might also increase the participation of obese women.
Women with chronic illness were more likely to undergo a Pap smear test compared to women without chronic illness. Because of their diagnosis they might go more regular health checks and during these visits they can be encouraged to participate in screenings also.
A more unexpected result was that women feeling depressed in the past 30 days were more likely to undergo a Pap smear test compared to women not feeling depressed. This result differs from other studies where unhappy and depressed women reported having a lower likelihood of cancer screening [15, 28, 34] but it can arise from differences in research methodology and scales of measuring depression and this result should be considered with caution.
Unhealthy lifestyle choices were associated with Pap smear uptake. Not being physically active during leisure time or not being able to exercise due to any health condition were found to be strong predictors of not undergoing a Pap smear test, as found in other studies [13, 15, 16, 35] including in one Estonian study [10]. In accordance with similar studies, our findings showed that daily smokers were less likely to use Pap smear testing than never smokers [10, 26,27,28]. Smoking is a risk factor for both CC and the HPV that causes it, so if smoking increases the chances of not getting a Pap smear for early detection of CC, the risks accumulate [36]. Being physically active and non-smoking are part of a person’s health behaviour like taking care of one’s health and attending a screening.
Based on our results, an effective cervical cancer prevention policy in Estonia should focus on non-Estonian, single, less educated, unemployed, overweight and obese, physically inactive and daily smoking women.
The main strength of this study is the use of a nationally representative sample and a long study period. The methodology of the survey, which started already in 1990, has been maintained the same and therefore the results of different years are comparable. It was also considered having self-reported data as a strength as it gives a valuable insight into women’s lifestyle and preferences over the course of 16 years and includes Pap smears taken by private health care providers. At the same time, it was acknowledged that the self-reported information might have led to an overestimation of adherence to cancer screening [37, 38]. In addition, while it would have been more suitable to measure timely Pap smear uptake (3- or 5-year interval) lifetime uptake of Pap smear was used instead, as there was no data in such detail from 2004 survey. At the same time, by omitting the 2004 survey completely, valuable baseline information about the pre-screening era would be lost, which would have narrowed the results of this study. Furthermore, it was suspected that not all women knew what a Pap smear is or what kind of tests are taken during a regular health check since it was necessary to exclude 3.7% of women who did not answer the question about giving a Pap smear and one third of respondents who did not answer about the initiator (doctor, screening or woman herself) of their most recent Pap smear (data not shown).