The authors have declared that no competing interests exist.
Conceived and designed the experiments: EC MS BP JKJ YK KSC. Performed the experiments: EC YYL HJY MS YK KSC. Analyzed the data: EC SL. Contributed reagents/materials/analysis tools: EC SL. Wrote the paper: EC JKJ KSC.
The possibility of developing breast cancer is a concern for all women; however, few studies have examined the relationship between cancer worry and the stages of adoption for breast cancer screening in Korea. Here, we investigated the associations between cancer worry, the stages of adopting breast cancer screening, and socio-demographic factors known to influence screening behaviors.
This study was based on the 2013 Korean National Cancer Screening Survey, an annual cross-sectional survey that utilized nationally representative random sampling to investigate cancer screening rates. Data were analyzed from 1,773 randomly selected women aged 40–74 years. Chi-squared tests and multinomial logistic analyses were conducted to determine the associations between cancer worry and the stages of adoption for breast cancer screening and to outline the factors associated with each stage.
Korean women were classified into the following stages of adoption for breast cancer screening: pre-contemplation (24.7%), contemplation (13.0%), action/maintenance (50.8%), relapse risk (8.9%), and relapse (2.6%). Women in the action/maintenance stages reported more moderate to higher levels of worry about getting cancer than those in the pre-contemplation stage. Further, age of 40–49 years and having private cancer insurance were associated with women in the action/maintenance stages.
Interventions to address breast cancer worry may play an important role in increasing participation and equity in breast cancer screening.
Breast cancer is one of the most common cancers around the world. According to GLOBOCAN fact sheets, 25% of all of the new cancer cases involve the breast. While breast cancer is the most frequent cancer among women of both highly and less developed nations [
In Korea, even though the incidence of breast cancer is not as high as that of Western countries, it is rapidly increasing. Breast cancer is the second most common type of cancer and the fifth leading cause of cancer death among Korean women [
Although organized breast cancer screening is offered, breast cancer screening rates for Korea (70.9% for the entire nation) are still below those for other developed countries [
In addition to achieving high initial rates, the maintenance of participation rates at subsequent rounds of screening is equally as important [
In this study, via a transtheoretical model, we aimed to examine the stages of adoption for breast cancer screening to outline the extents to which breast cancer worry affect the decisions of Korean women to undergo breast cancer screening or not. We also investigated associations between the stages of adopting breast cancer screening and socio-demographic factors known to influence screening behaviors. We suspect that providing detailed information on stages of adoption and factors influencing breast cancer screening will help researchers tailor health communication to increase participation in breast cancer screening.
Data were acquired from subjects included in the 2013 Korean National Cancer Screening Survey (KNCSS). The KNCSS is an annual cross-sectional survey performed to investigate screening rates among Koreans for five common cancers (gastric, liver, colorectal, breast, and cervix) through nationally representative random sampling. Men aged ≥40 years and women ≥30 years were selected based on Resident of Registration Population data for July 2013 compiled by Statistics Korea, using multistage random sampling according to sex, age, geographic area, and size of population per area. The survey was conducted from September 26 to October 18, 2013, at which time investigators from a professional research agency went door-to-door to recruit residents. At least three attempts were made to contact individual residents. The 2013 KNCSS included 4,100 participants among a total of 23,238 random samples (total response rate: 17.6%). The response rate after making contact was 64%, excluding those who were absent (16,533) or who did not meet the criteria for this survey (296). Of the respondents, 1,773 cancer-free women aged ≥40 years were finally included in the current study, since the NCSP only provides breast cancer screening for individuals aged ≥40 years.
Witten informed consent was obtained from all study participants before the face-to-face interview. This study was approved by the Institutional Review Board (IRB) of the National Cancer Center, Korea (approval number: NCCNCS-08-129). Informed consent was documented via the use of a written consent form approved by the IRB and signed by all study participants.
The stages of adoption for breast cancer screening were assessed via a modified five-stage process related to the subjects’ reported histories of breast cancer screening and their current intentions to undergo screening within the next 2 years, as recommended by Rakowski et al. in 1996 [ Pre-contemplation, had never undergone breast cancer screening and did not plan to within the next 2 years; Contemplation, had either never undergone breast cancer screening or had not in the last 1–2 years, but are planning to within the next 2 years; Action/Maintenance, had undergone breast cancer screening within the last 24 months and were planning on undergoing another test within the next 2 years; Relapse risk, had undergone breast cancer screening within the last 24 months, but were not planning on undergoing another test within the next 2 years; Relapse, had undergone one or more breast cancer screening test in the past, but were now off schedule and had no plans to undergo breast cancer screening within the next 2 years.
To develop survey questions related to cancer worry and perceived risk, we reviewed previous research. Since measurements of cancer worry and perceived risk were not available in the Korean language, questionnaires written in English were first translated into Korean and then translated back into English to confirm the accuracy of the translation. Further, we conducted a pilot survey to assess understanding of these questions among respondents. In the present study, Lerman’s Cancer Worry Scale modified to reflect cancer worry in Korea was used [
We also examined several socioeconomic (age, marital status, level of education, and monthly household income) and health-related factors (regular exercise, undergoing regular health checkups, and family history of any cancer) to assess their influence on screening behaviors. Further, private cancer insurance and awareness of the NCSP were also measured to assess the accessibility of breast cancer screening. Although the NHIS provides universal coverage to all Koreans, many Koreans pay for supplementary private health insurance in the event of illness (e.g., cancer or stroke) due to insufficient coverage with the NHIS [
Descriptive statistics were assessed to characterize the study population. For comparison of cancer worry levels with worry levels for five major non-communicable diseases, ANOVA and Tukey’s post-hoc analysis were conducted. Chi-squared tests were used to compare the distributions of the stages of adoption according to socioeconomic and health-related factors. To investigate factors related to one’s stage of adoption, we grouped participants into four groups: 1) pre-contemplation; 2) contemplation; 3) action/maintenance; and 4) relapse risk/relapse group. Multinomial logistic analysis was conducted to identify associations between breast cancer worry and the stages of adoption for breast cancer screening, as well as factors associated with each stage. In this analysis, we combined the relapse risk and relapse stages, because the number of women who were in the relapse stage was too small to conduct multivariate analysis. Further, women in the relapse risk and relapse share the same experience in that they have already been in action or maintenance. We assessed the adjusted odds of being in the action/maintenance group or relapse risk/relapse group rather than the pre-contemplation group. All variables with a
Descriptive data for the subjects according to their levels of cancer worry are presented in
Cancer Worry | |||||
---|---|---|---|---|---|
n (%) | High | Moderate | Low | ||
Total | 1773(100.0) | 477(26.9) | 622(35.1) | 674(38.0) | |
Age(years) | 0.006 | ||||
40–49 | 665(37.5) | 159(23.9) | 262(39.4) | 244(36.6) | |
50–59 | 605(34.1) | 165(27.2) | 188(31.0) | 252(41.6) | |
60–74 | 503(28.3) | 153(30.4) | 172(34.2) | 178(35.4) | |
Monthly Household Income ($) | 0.396 | ||||
<2500 | 448(25.3) | 128(28.5) | 140(31.2) | 180(40.1) | |
2500–4990 | 763(43.0) | 198(25.9) | 276(36.1) | 289(37.8) | |
>5000 | 561(31.6) | 151(26.9) | 205(36.5) | 205(36.5) | |
Education | 0.400 | ||||
Middle and high school graduate | 1367(77.1) | 363(26.5) | 491(35.9) | 513(37.5) | |
Undergraduate college degree or higher | 406(22.9) | 114(28.0) | 131(32.2) | 161(39.6) | |
Marital Status | 0.661 | ||||
Other | 171(9.6) | 50(29.2) | 61(35.6) | 60(35.0) | |
Married | 1602(90.4) | 427(26.6) | 561(35.0) | 614(38.3) | |
Residential Area | 0.351 | ||||
Urban | 791(44.6) | 224(28.3) | 276(34.8) | 291(36.7) | |
Suburban | 733(41.3) | 183(24.9) | 269(36.7) | 281(38.3) | |
Rural | 249 (14.0) | 70 (28.1) | 77 (30.9) | 102 (40.9) | |
Private Cancer Insurance | 0.441 | ||||
Yes | 1453(82.0) | 389(26.7) | 502(34.5) | 562(38.6) | |
No | 320(18.0) | 88(27.5) | 120(37.5) | 112(35.0) | |
Family History of Cancer | 0.062 | ||||
Yes | 467(26.3) | 144(30.8) | 149(31.9) | 174(37.2) | |
No | 1306(73.7) | 333(25.5) | 473(36.2) | 500(38.2) | |
Knowledge of the NCSP | 0.019 | ||||
Yes | 1395(78.6) | 388(27.8) | 500(35.8) | 507(36.3) | |
No | 378(21.3) | 89(23.5) | 122(32.2) | 167(44.2) | |
Regular Exercise | 0.962 | ||||
Yes | 831(46.9) | 221(26.5) | 293(35.2) | 317(38.1) | |
No | 942(53.1) | 256(27.1) | 329(34.9) | 357(37.9) | |
Regular Health Checkups | 0.781 | ||||
Yes | 849(47.9) | 223(26.2) | 304(35.8) | 322(37.9) | |
No | 924(52.1) | 254(27.4) | 318(34.4) | 352(38.1) | |
Perceived Risk for Breast Cancer | 0.973 | ||||
High | 402(22.7) | 106(26.3) | 143(35.5) | 153(38.0) | |
Moderate | 974(54.9) | 265(27.2) | 344(35.3) | 365(37.4) | |
Low | 397(22.4) | 106(26.7) | 135(34.0) | 156(39.2) |
NCSP, National Cancer Screening Program
Non-communicable disease | Mean ± s.d. | |
---|---|---|
Cancer | 3.05 ± 0.84 | <0.00 |
Alzheimer’s |
2.66 ± 0.99 | |
Stroke |
2.65 ± 0.99 | |
Hypertension |
2.63 ± 0.98 | |
Cardiovascular disease |
2.55 ± 0.91 | |
Diabetes |
2.49 ± 0.98 |
aThe mean difference between cancer worry and each disease is statistically significant at a level of significance of
In the present study, we classified respondents according to stage of adoption for breast cancer screening. Among the study population, 24.7% were classified in the pre-contemplation stage, 13.0% in the contemplation stage, 50.8% in the action/maintenance stage, 8.9% in the relapse risk stage, and 2.6% in the relapse stage. Age, monthly household income, private cancer insurance, regular health checkups, and cancer worry were significantly different across the stages of adoption of breast cancer screening (
Pre-contemplation | Contemplation | Action / Maintenance | Relapse risk | Relapse | ||
---|---|---|---|---|---|---|
n (%) | n (%) | n (%) | n (%) | n (%) | ||
Total | 438 (24.7) | 231 (13.0) | 901 (50.8) | 157 (8.9) | 46 (2.6) | |
Age(years) | 0.043 | |||||
40–49 | 141 (21.2) | 85 (12.7) | 371 (55.7) | 53 (7.9) | 15 (2.2) | |
50–59 | 158 (26.1) | 74 (12.2) | 305 (50.4) | 53 (8.7) | 15 (2.4) | |
60–74 | 139(27.6) | 72(14.3) | 225(44.7) | 51(10.1) | 16(3.2) | |
Monthly Household Income ($) | 0.032 | |||||
<2500 | 111 (24.7) | 66 (14.7) | 213 (47.5) | 40 (8.9) | 18 (4.0) | |
2500–4990 | 209 (27.3) | 97 (12.7) | 373 (48.8) | 66 (8.6) | 18 (2.3) | |
>5000 | 117 (20.8) | 68 (12.1) | 315 (56.1) | 51 (9.0) | 10 (1.7) | |
Education | 0.565 | |||||
Middle and high school graduate | 346 (25.3) | 169 (12.3) | 695 (50.8) | 121 (8.8) | 36 (2.6) | |
Undergraduate college degree or higher | 92 (22.6) | 62 (15.2) | 206 (50.7) | 36 (8.8) | 10 (2.4) | |
Marital Status | 0.112 | |||||
Other | 45 (26.3) | 32 (18.7) | 73 (42.6) | 16 (9.3) | 5 (2.9) | |
Married | 393 (24.5) | 199 (12.4) | 828 (51.6) | 141 (8.8) | 41 (2.5) | |
Residential Area | 0.028 | |||||
Urban | 182 (23.0) | 83 (10.4) | 425 (53.7) | 82 (10.3) | 19 (2.4) | |
Suburban | 194 (26.4) | 109 (14.8) | 351 (47.8) | 59 (8.0) | 20 (2.7) | |
Rural | 62 (24.9) | 39 (15.6) | 125 (50.2) | 16 (6.4) | 7 (2.8) | |
Private Cancer Insurance | 0.026 | |||||
Yes | 339 (23.3) | 198 (13.6) | 753 (51.8) | 128 (8.8) | 35 (2.4) | |
No | 99 (30.9) | 33 (10.3) | 148 (46.2) | 29 (9.0) | 11 (3.4) | |
Family History of Cancer | 0.311 | |||||
Yes | 125 (24.7) | 49 (10.4) | 235 (50.3) | 45 (9.6) | 13 (2.7) | |
No | 313 (23.9) | 182 (13.9) | 666 (51.0) | 112 (8.5) | 33 (2.5) | |
Knowledge of the NCSP | 0.073 | |||||
Yes | 328(23.5) | 189(13.3) | 725(51.9) | 117(8.4) | 39(2.8) | |
No | 110(29.1) | 45(11.9) | 176(46.5) | 40(10.5) | 7(1.8) | |
Regular Exercise | 0.056 | |||||
Yes | 220 (26.4) | 119 (14.3) | 395 (47.5) | 71 (8.5) | 26 (3.1) | |
No | 218 (23.1) | 112 (11.8) | 506 (53.7) | 86 (9.1) | 20 (2.1) | |
Regular Health Checkups | 0.010 | |||||
Yes | 209 (24.6) | 98 (11.5) | 462 (54.4) | 64 (7.5) | 16 (1.8) | |
No | 229 (24.7) | 133 (14.3) | 439 (47.5) | 93 (10.0) | 30 (3.2) | |
Cancer Worry | 0.008 | |||||
High | 116 (24.3) | 47 (9.8) | 250 (52.4) | 50 (10.4) | 14 (2.9) | |
Moderate | 134 (21.5) | 81 (13.0) | 344 (55.3) | 48 (7.7) | 15 (2.4) | |
Low | 188 (27.8) | 103 (15.2) | 307 (45.5) | 59 (8.7) | 17 (2.5) | |
Perceived Risk for Breast Cancer | 0.662 | |||||
High | 90 (22.3) | 55 (13.6) | 214 (53.2) | 35 (8.7) | 8 (1.9) | |
Moderate | 246 (25.2) | 121 (12.4) | 500 (51.3) | 83 (8.5) | 24 (2.4) | |
Low | 102 (25.6) | 55 (13.8) | 187 (47.1) | 39 (9.8) | 14 (3.5) |
NCSP, National Cancer Screening Program
Contemplation | Action/Maintenance | Relapse risk or Relapse | |||||||
---|---|---|---|---|---|---|---|---|---|
aOR | 95% CI | aOR | 95% CI | aOR | 95% CI | ||||
Age(years) | |||||||||
40–49 | 1.13 | 0.75–1.68 | 0.627 | 1.64 | 1.22–2.20 | 0.001 | 1.01 | 0.66–1.52 | 0.841 |
50–59 | 0.89 | 0.59–1.32 | 1.23 | 0.92–1.64 | 0.90 | 0.59–1.36 | |||
60–74 | 1.00 | 1.00 | 1.00 | ||||||
Monthly Household Income ($) | |||||||||
<2500 | 0.76 | 0.51–1.13 | 0.845 | 0.86 | 0.64–1.15 | 0.051 | 0.73 | 0.48–1.13 | 0.859 |
2500–4990 | 0.94 | 0.61–1.45 | 1.30 | 0.95–1.79 | 0.95 | 0.60–1.49 | |||
>5000 | 1.00 | 1.00 | 1.00 | ||||||
Residential Area | |||||||||
Urban | 0.72 | 0.45–1.17 | 0.150 | 1.12 | 0.78–1.59 | 0.219 | 1.51 | 0.88–2.60 | 0.076 |
Suburban | 0.88 | 0.55–1.41 | 0.84 | 0.59–1.21 | 1.12 | 0.64–1.94 | |||
Rural | 1.00 | 1.00 | 1.00 | ||||||
Private Cancer Insurance | |||||||||
Yes | 1.73 | 1.12–2.67 | 1.43 | 1.07–1.92 | 1.19 | 0.78–1.81 | |||
No | 1.00 | 1.00 | 1.00 | ||||||
Regular Health Checkups | |||||||||
Yes | 0.79 | 0.57–1.10 | 1.18 | 0.94–1.49 | 0.71 | 0.51–1.01 | |||
No | 1.00 | 1.00 | 1.00 | ||||||
Cancer Worry | |||||||||
High | 0.74 | 0.49–1.13 | 0.263 | 1.34 | 1.01–1.79 | 0.021 | 1.34 | 0.89–2.01 | 0.690 |
Moderate | 1.12 | 0.77–1.62 | 1.58 | 1.20–2.08 | 1.17 | 0.78–1.76 | |||
Low | 1.00 | 1.00 | 1.00 |
a Comparison to the pre-contemplation group
Between the pre-contemplation and contemplation stages, only private cancer insurance was significantly different; women who had private cancer insurance were more likely to be in the contemplation stage than the pre-contemplation stage. In comparison of the pre-contemplation and action/maintenance stages, women aged 40–59 years who had private cancer insurance and who reported higher levels of cancer worry were more likely to stay in the action/maintenance stage than the pre-contemplation stage. However, between the pre-contemplation and relapse risk/relapse stages, no statistically significant difference was noted.
In the present study, we assessed the associations between cancer worry and stages of adoption for breast cancer screening in the general Korean population. Although previous studies have investigated the importance of the role of breast cancer worry in promoting participation in cancer screening [
Across the stages of adoption, several factors were shown to influence differences in the distribution thereof in the present study. Mainly, subjects who reported relatively greater concerns for getting cancer were more likely to be classified in on-schedule stages (contemplation and action/maintenance). Additionally, age, monthly household income, private cancer insurance, undergoing regular health checkups, and cancer worry were significantly different across the stages of adoption for breast cancer screening. Meanwhile, perceived risk showed no significant difference across the stages of adoption. Reviewing previous studies, the effect of perceived risk on intention to undergo mammography was still unclear, though it has been studied as a promoter of preventive health behavior [
In summary of the percent distribution across the stages of breast cancer screening adoption for Korean women, only about 63.8% reported on-schedule screening (contemplation 13.0%, action/maintenance 50.8%), while 36.2% did not (pre-contemplation 24.7%, relapse risk 8.9%, andrelapse 2.6%). These screening rates are much lower than those for on-schedule screening in the United States (84.0%) [
Among our results from multinomial logistic analysis, we found that cancer worry played a role in boosting cancer screening behaviors overall. Compared to those with relatively low cancer worry, subjects with relatively high levels of cancer worry were more likely to be classified in the action/maintenance stage than the pre-contemplation stage. Between the pre-contemplation stage group and the relapse risk/relapse stage group, those who reported relatively greater concerns for getting cancer were more likely to be classified in the relapse risk/relapse stages, suggesting that women with little to no concerns for getting cancer had not even considered undergoing breast cancer screening, in the past or the future. As introduced above, despite the existence of several contradictory results, cancer worry has predominantly been shown to play a critical role in motivating screening behavior, with which our results agree [
Herein, we also examined socio-economic factors in relation to their effects on breast cancer screening behavior. In doing so, we discovered that Korean women aged 40–59 years, who are at high risk for breast cancer, are more likely to remain in the action/maintenance stages than the pre-contemplation stage (
Our study has a number of limitations. First, the cross-sectional design of this study hindered our ability to implicate any causal relationship for the observed associations. Thus, future studies with a longitudinal design should be conducted to track patterns in breast cancer screening behaviors. Second, because of memory bias, we assessed only the most recent breast cancer screening event and did not collect information on screening events that preceded the most recent one. Therefore, we could not distinguish between the action and maintenance stages. Further, we only measured overall cancer worry not breast cancer-specific worry, as we were concerned that there might be somewhat different trends between overall cancer worry and breast cancer-specific worry. Thus, studies that distinguish between worry for individual types of cancer are needed, as are validation studies to develop reliable and capable measures of predicting unique variances in cancer-relevant worry in the Korean population.
Despite these limitations, this study is important in that it is the first to assess breast cancer worry specifically in relation to its effects on screening behavior among Korean women. As well, this study provides new insights that may be of use in guiding the development of intervention strategies for improving compliance with breast cancer screening recommendations at the population level. Our results demonstrated that cancer worry is associated with continued breast cancer screening among women in Korea. Additionally, we showed that age, household income, private cancer insurance, and regular health checkups are positively associated with the stages of breast cancer screening adoption among Korean women. Interventions to address breast cancer worry may play an important role in increasing participation and equity in breast cancer screening.
The authors would like to thank Anthony Thomas Milliken (Editing Synthase, Seoul, Korea) for his help with the editing of this manuscript.