2025 Volume 7 Issue 1 Article ID: 2024-0017
Objectives: Hypertension and dyslipidemia are major risk factors of cardiovascular diseases. Nevertheless, many people do not consider these risk factors important, even if they are noted during their annual health checkups and left untreated for a long time. Here, we report a novel nudge method to encourage people who had these risk factors and examine the resultant changes in the willingness to undergo secondary health examinations. Methods: Employees of Novartis Pharma K.K. and its affiliated companies who had elevated blood pressure and/or lipid levels during annual health checkups were allocated to either the social nudge group (postcards were sent to their spouses) or the control group (postcards were sent to themselves) after confirming their agreement to receive postcards in order to encourage them to take secondary health examination. A web-based survey via email was conducted before and after sending the postcards to understand the willingness to undergo secondary health examinations. Results: Regarding the willingness to undergo the secondary health examinations, a significant difference was observed in the social nudge group (n=58) before (12.1%) and after (46.6%) the postcard was sent (p<0.0001), and no significant difference was observed in the control group (n=9, p=1.0000). The proportion of employees who underwent secondary health examinations did not increase significantly in either group. Conclusions: This study suggested that a social nudge via spouse has a possibility of increasing the willingness to undergo secondary health examinations at low cost. To increase the proportion of undergoing it, combinations with other nudges might be necessary.
Non-communicable diseases, such as hypertension, among the working generation are serious issues1). Occupational health is important for preventing them2). In Japan, in accordance with Article 66 of the Industrial Safety and Health Act, employers must conduct annual health checkups for workers, and workers must undergo them. Particularly in large companies, health insurance associations are established, and the results of periodic health checkups are managed by the insurers. The responsibility for recommending secondary health examinations and other health services is shared between the health insurance associations and the companies. Those who are diagnosed as “requiring detailed examination” or “requiring medical care” during annual health checkups are recommended to undergo non-mandatory secondary health examinations. As a result, for example, only about one-third of Japanese individuals aged 40–74 years with findings of grade II-III hypertension (systolic blood pressure [SBP]/diastolic blood pressure [DBP] >160/100 mm Hg) undergo secondary health examinations3). Therefore, an effective intervention for increasing utilization of secondary health examinations is required.
To improve the proportion of workers undergoing secondary health examinations, it is important to provide information on the necessity of consultation. However, many people have a cognitive bias and do not always act as they do when they are properly informed. A secondary health examination is an intertemporal choice, in which costs occur right now and the effects appear in the future4). Individuals with a strong present bias would prefer to postpone undergoing secondary health examinations because of hesitation for current sacrifices for the future health effects. To make better decisions in intertemporal choices, nudging can be a useful intervention. A nudge is defined as any aspect of the choice architecture that alters people’s behavior in a predictable way without forbidding any options or significantly changing their economic incentives5).
The Ministry of Health, Labour and Welfare in Japan introduced some cases that improved the proportions of annual health checkups and cancer screening according to the EAST (easy, attractive, social and timely) nudge framework6). These cases were investigated mainly for annual health checkups and cancer screening; however, it has not been clarified whether the nudge technique for secondary health examinations is effective or not.
Support by family members, which may be modifiable via social nudge, is expected to have a positive effect on the health7). It is assumed that a moderate intervention, such as sending a postcard to the spouse of an employee who has given consent, is easy for companies to implement. However, there have been no studies to verify the effect of nudges through family members. This report aimed to examine changes in the willingness to undergo secondary health examinations through spouse nudging performed on individuals with findings during the annual health checkups.
Participants were selected based on their health conditions and consent to the study. Briefly, employees of Novartis Pharma K.K. and its affiliated companies (hereinafter referred to as employees) who participated in their annual health checkup from April 1, 2022, to March 31, 2023 and had a finding of hypertension (SBP/DBP >140/90 mm Hg) and/or dyslipidemia (low density lipoprotein cholesterol [LDL-C] >140 mg/dL or triglyceride [TG]>150 mg/dL) in the annual health checkups were included. Exclusion criteria were those who were not employed by the company as of 4 months after the date of their annual health checkups, those who were taking medicines for hypertension or dyslipidemia at annual health checkups, and those who did not answer the preliminary survey described below. Employees who did not agree to participate were also excluded from the program.
Survey method and nudge Preliminary surveyA self-administered questionnaire was emailed to all employees on April 18, 2022. The main question inquired about the willingness to visit a medical institution regarding his/her blood pressure (BP) or LDL-C level, giving five response options: (a) I do not plan to visit the medical institution because the value is within the reference range, (b) I do not plan to visit the medical institution though the value is outside the reference range, (c) I plan to visit the medical institution in 6 months, (d) I plan to visit the medical institution in 1 month, and (e) I have already visited the medical institution. In addition, we also informed that employees living with spouses can voluntarily register the names to receive a postcard after annual health checkups.
Group assignment and interventionAmong those with a finding of hypertension and/or dyslipidemia in annual health checkups who were not taking hypertension/dyslipidemia drugs, those who registered the name of the spouse living together in the preliminary survey were assigned to the social nudge group, and those who did not were assigned to the control group. After the annual health checkups, a sealed postcard was sent to their spouses in the social nudge group (Figure 1A) or employees themselves in the control group (Figure 1B). The postcard in the control group encouraged the employees to undergo a secondary health examination. On the other hand, for employees in social nudge group, the postcard to the employees’ spouses suggested that they encourage the employees to take secondary health examinations. In both groups, the employees were encouraged to make an appointment for a secondary health examination on the left side, and a short comment from the general industrial physician was described on the right side (Figure 1C).
Approximately 2 months after the postcard delivery, employees were asked to answer the follow-up survey via email. Both groups were asked the same questions as the preliminary survey, together with an additional question to ask if they were aware of the delivered postcard.
OutcomesThe primary outcomes were the change in willingness to undergo a secondary health examination before and after sending a postcard with a recommendation for a secondary health examination and the proportion of employees receiving a secondary health examination within 4 months of receiving a routine health checkup. The secondary outcome was the proportion of recognition of the postcard.
Analysis methodsCategorical variables were tested for significance using the chi-square test with Yates’ correction or Fisher’s exact test. The willingness to undergo secondary health examination was analyzed with the following categories: option (a), (b), and (c) were considered as “not willing to visit secondary health examination”, (d), and (e) were considered as “willing to visit”. Consultation for secondary health examination was determined based on whether a health insurance claim with a diagnosis record of International Classification of Diseases (ICD) 10 code I10 (essential [primary] hypertension) or E78 (disorders of lipoprotein metabolism and other lipidaemia) had been issued in the month of regular health checkup and the following month to 4 months. Statistically significant level was set at p<0.05.
Ethical considerationsThis study was approved by the Ethical Review Board of Hillside Clinic in accordance with the Act on the Protection of Personal Information and the Ethical Guidelines for Life Science, Medical and Health Research Involving Human Subjects (CLCZ696AJP08). A written explanation was given to participants, and opt-in consent was obtained. The delivery of postcards and the surveys were conducted solely by Novartis Health Insurance Association to protect personal information. Only the employees who agreed to the secondary use of data in each survey were included in the analysis with an anonymized manner.
A total of 3,239 employees participated in the annual health checkup in fiscal year 2022. The number of employees who met the inclusion criteria and agreed to the secondary use of data were 148 in the social nudge group and 38 in the control group. Among these, 58 employees and 9 employees responded to both the preliminary and follow-up surveys, respectively, and were enrolled for the following analyses.
Change in willingness to undergo a secondary health examination, proportion of receiving a secondary health examination, and proportion of recognition of a postcardIn the social nudge group, 7 employees (12.1%) were willing to undergo the secondary health examination before sending the postcard, and the number increased to 27 employees (46.6%) after sending the postcard, showing significant progress (p<0.0001). In the control group, 3 employees (33.3%) showed willingness to undergo the secondary health examination before and after sending the postcard (p=1.0000). No significant difference was observed between these groups after sending the postcard (p=0.7206) (Table 1). However, among individuals with evidence of hypertension and/or dyslipidemia, the number and proportion of secondary health examinations within 4 months after the routine health check-up was 22 (14.9%) in the social nudge group and 7 (18.4%) in the control group, showing no statistical significance (p=0.7731).
| Social Nudge Group (n=58) | Control Group (n=9) | p-value between groups | ||
|---|---|---|---|---|
| [Outcome] Willing to visit a | Before postcard delivery | 7 (12.1%) | 3 (33.3%) | ― |
| After postcard delivery | 27 (46.6%) | 3 (33.3%) | 0.7206 | |
| p-value within group | <0.0001 | 1.0000 |
The number of employees who were aware of the postcard in the social nudge group was 43 (74.1%), while it was 5 (55.6%) in the control group.
In the social nudge group, the motivation to undergo secondary health examination was significantly increased. This may be because the exhortation postcard functioned as an altruistic nudge, meaning that they did not want to cause trouble to their spouse; a commitment nudge, appealing to the mentality of hesitation to tell the spouse about the procrastination; and a peer nudge, meaning that their spouse would visit the medical institution and so would they. All are consistent with the precedent case of promotion of cancer screening and influenza vaccine uptake8,9). Although there have been few previous studies on the promotion of secondary health examinations, some studies have argued the importance of familial interference toward primary examination, showing positive effects on recommendations from family members10,11). The findings of this study suggest a novel method to promote secondary health examinations.
In addition, the nudges conducted in our study required no cost other than the costs associated with administering the preliminary survey and the fee for postcards. Enterprises prefer simple, low-cost methods that encourage workers to engage in healthy behaviors12). In that regard, the nudges are suggested to be cost-effective and consistent with the findings of previous research13). A previous study applied text message-based nudges and significantly increased hypertension care retention, which could be an alternative to postcard-based intervention14).
On the other hand, the proportion of workers undergoing secondary health examinations did not improve significantly. This suggests the possibility of a bottleneck before the action stage. Considering the report that the most effective interventions are combinations of different elements, interventions only with social nudges may not be sufficient to overcome the barrier15). Combining multiple nudges or other methods might be necessary to increase the proportion of workers attending secondary health examinations.
Our study has several limitations. First, because of the nature of this study, we could not assemble a sufficient number of participants to assess changes with high statistical power. Moreover, selection bias might have occurred. Second, the findings may not be generalizable to broader populations because the participants were employed by a specific pharmaceutical company. In the future, it is expected that reliable verification will be conducted by larger organizations. Third, this study was not a randomized controlled trial, and the potential impact of external factors could not be dismissed. Some participants did not visit a medical institution despite being recommended, which might be attributed to a decrease in their blood pressure resulting from lifestyle improvements and may have reduced their perceived need for further evaluation. Additionally, individuals who had previously visited a medical institution with similar health checkup results and were informed that no treatment was necessary might have been less motivated to seek follow-up care. This potential bias could have affected either group and needs to be adjusted in future studies. Despite these limitations, this is a unique study that suggests the possibility of increasing the proportion of workers undergoing secondary health examinations by sending a notification advising the employees’ spouses to seek medical attention.
To summarize, we demonstrated a positive effect on willingness to undergo secondary health examinations when an employee’s spouse has received a postcard to encourage. The social nudge could be a useful tool for occupational health.
This study was funded by Novartis Pharma K.K. SE, and KI are employees of Novartis Pharma K.K. WK and MS is a former employee of Novartis Pharma K.K. and/or the related organization. Data analysis was supported by JMDC. Inc., and preparation of this manuscript was supported by Dr. Koki Yamashita of Maxwell International, Inc. with funding from Novartis Pharma K.K.
This study was carried as secondary use of data and was approved by the Institutional Review Board of Hillside Clinic, Japan, in accordance with the Act on the Protection of Personal Information and the Ethical Guidelines for Life Science, Medical and Health Research Involving Human Subjects. Informed consent: We explained the possibility of postcard delivery and secondary use of data and obtained opt-in consent. Registry and the registration no. of the study/trial: N/A. Animal studies: N/A.
The data used in this report are not publicly available. Please contact the authors for more information.
WK, SE, MT and KI designed the study. MS designed the postcard. MS conducted the surveys. WK wrote the manuscript. MS, SE, MT and KI revised the manuscript. All authors approved the final draft.
