Table 3.
Results of the fully adjusted multinomial logistic regression analyses at wave 1
| Predictors | Undecided | Unwilling | ||||
|---|---|---|---|---|---|---|
| RRR | 95% CI | P-value | RRR | 95% CI | P-value | |
| Sex | ||||||
| Male | reference | reference | ||||
| Female | 1.19 | (1.07–1.32) | 0.001 | 1.13 | (0.96–1.32) | 0.145 |
| Age group, years | ||||||
| 65+ | reference | reference | ||||
| 50–64 | 2.35 | (2.04–2.70) | < 0.001 | 1.82 | (1.44–2.29) | < 0.001 |
| 30–49 | 3.58 | (3.06–4.19) | < 0.001 | 3.04 | (2.35–3.91) | < 0.001 |
| 18–29 | 4.16 | (3.35–5.16) | < 0.001 | 4.46 | (3.23–6.15) | < 0.001 |
| Highest education | ||||||
| Junior/senior high school | 1.21 | (1.09–1.35) | < 0.001 | 1.32 | (1.11–1.56) | 0.001 |
| Two- or three-year college | 1.08 | (0.96–1.22) | 0.185 | 1.28 | (1.06–1.54) | 0.009 |
| Four-year college or higher | reference | reference | ||||
| Family members living together | ||||||
| Living alone | 1.33 | (1.15–1.54) | < 0.001 | 1.46 | (1.16–1.84) | 0.001 |
| Living only with spouses | reference | reference | ||||
| Living with children | 1.15 | (1.02–1.29) | 0.027 | 1.20 | (0.98–1.47) | 0.082 |
| Living with parents | 1.34 | (1.16–1.55) | < 0.001 | 1.46 | (1.16–1.84) | 0.001 |
| Three generation household | 1.49 | (1.21–1.83) | < 0.001 | 1.40 | (0.99–1.98) | 0.059 |
| Others (siblings only, friends, grandparents and grandchildren etc.) | 1.38 | (0.97–1.96) | 0.077 | 1.88 | (1.17–3.00) | 0.009 |
| Employment | ||||||
| Employed | reference | reference | ||||
| Homemaker | 1.09 | (0.95–1.25) | 0.208 | 0.86 | (0.68–1.08) | 0.198 |
| Not employed (seeking a job) | 0.98 | (0.74–1.28) | 0.858 | 0.98 | (0.67–1.45) | 0.937 |
| Not employed (not seeking job) | 1.06 | (0.91–1.24) | 0.437 | 1.29 | (1.03–1.61) | 0.026 |
| Student | 0.88 | (0.64–1.21) | 0.420 | 0.72 | (0.46–1.11) | 0.137 |
| Other | 1.60 | (1.05–2.42) | 0.028 | 1.99 | (1.14–3.47) | 0.015 |
| Annual household income, million yen | ||||||
| < 3 | 1.35 | (1.15–1.58) | < 0.001 | 1.39 | (1.09–1.77) | 0.008 |
| 3–4 | 0.99 | (0.86–1.14) | 0.871 | 0.96 | (0.77–1.20) | 0.730 |
| 5–7 | 1.12 | (0.98–1.28) | 0.086 | 0.87 | (0.70–1.08) | 0.216 |
| ≥ 8 | reference | reference | ||||
| Bank and saving deposit amount, million yen | ||||||
| < 1 | 1.44 | (1.27–1.64) | < 0.001 | 1.45 | (1.18–1.77) | < 0.001 |
| 1–3 | 1.23 | (1.08–1.40) | 0.002 | 1.13 | (0.92–1.40) | 0.242 |
| 4–9 | 1.23 | (1.08–1.39) | 0.001 | 1.13 | (0.92–1.39) | 0.238 |
| ≥ 10 | reference | reference | ||||
| BMI | ||||||
| < 18.5 | 1.17 | (1.03–1.34) | 0.019 | 1.34 | (1.10–1.62) | 0.003 |
| 18.5–24.9 | reference | reference | ||||
| 25.0-29.9 | 0.94 | (0.83–1.07) | 0.341 | 1.02 | (0.84–1.25) | 0.827 |
| ≥ 30.0 | 0.97 | (0.75–1.26) | 0.833 | 0.76 | (0.49–1.19) | 0.232 |
| Pre-existing condition | ||||||
| Hypertension | 0.79 | (0.69–0.90) | < 0.001 | 0.62 | (0.49–0.78) | < 0.001 |
| Dyslipidemia | 0.62 | (0.52–0.73) | < 0.001 | 0.68 | (0.51–0.91) | 0.009 |
| Diabetes | 0.95 | (0.77–1.17) | 0.610 | 0.88 | (0.62–1.27) | 0.501 |
| Heart disease | 0.86 | (0.63–1.17) | 0.338 | 0.94 | (0.56–1.56) | 0.802 |
| Renal disease | 1.12 | (0.67–1.85) | 0.674 | 0.70 | (0.27–1.81) | 0.467 |
| Cancer | 0.74 | (0.50–1.09) | 0.126 | 0.82 | (0.44–1.52) | 0.522 |
| Respiratory disease | 0.97 | (0.71–1.31) | 0.838 | 1.23 | (0.78–1.92) | 0.369 |
| Other condition | 1.03 | (0.71–1.47) | 0.890 | 1.02 | (0.58–1.77) | 0.952 |
| Region of residence | ||||||
| Tokyo | reference | reference | ||||
| Kanagawa | 1.05 | (0.85–1.29) | 0.652 | 0.64 | (0.45–0.90) | 0.011 |
| Osaka | 0.93 | (0.75–1.14) | 0.479 | 0.83 | (0.60–1.13) | 0.237 |
| Aichi | 0.90 | (0.72–1.12) | 0.343 | 0.80 | (0.57–1.11) | 0.180 |
| Saitama | 1.12 | (0.90–1.39) | 0.319 | 0.69 | (0.48–1.00) | 0.049 |
| Chiba | 0.93 | (0.73–1.17) | 0.525 | 1.05 | (0.75–1.47) | 0.776 |
| Hyogo | 0.92 | (0.72–1.17) | 0.496 | 0.87 | (0.61–1.25) | 0.457 |
| Hokkaido | 0.86 | (0.67–1.10) | 0.225 | 0.80 | (0.55–1.15) | 0.227 |
| Fukuoka | 0.84 | (0.64–1.09) | 0.187 | 1.01 | (0.70–1.46) | 0.964 |
| Tohoku region | 0.74 | (0.59–0.91) | 0.005 | 0.61 | (0.44–0.86) | 0.004 |
| North Kanto | 1.15 | (0.92–1.45) | 0.228 | 0.84 | (0.59–1.22) | 0.365 |
| Hokuriku | 0.92 | (0.71–1.18) | 0.501 | 0.64 | (0.42–0.97) | 0.037 |
| Chubu | 1.06 | (0.86–1.30) | 0.593 | 0.67 | (0.47–0.93) | 0.019 |
| Kinki | 0.96 | (0.78–1.19) | 0.713 | 0.96 | (0.71–1.31) | 0.817 |
| Chugoku | 1.30 | (1.05–1.63) | 0.018 | 0.89 | (0.63–1.27) | 0.535 |
| Shikoku | 0.81 | (0.60–1.09) | 0.156 | 0.81 | (0.52–1.27) | 0.358 |
| Kyushu and Okinawa | 1.10 | (0.89–1.36) | 0.389 | 0.86 | (0.61–1.19) | 0.354 |
| Generalized trust | ||||||
| Most people can be trusted | reference | reference | ||||
| Need to be very careful | 1.28 | (1.16–1.41) | < 0.001 | 1.59 | (1.35–1.87) | < 0.001 |
| Don’t know | 1.65 | (1.34–2.04) | < 0.001 | 1.90 | (1.37–2.63) | < 0.001 |
| Depression (PHQ-9) | ||||||
| None (0–4) | reference | reference | ||||
| Mild (5–9) | 1.19 | (1.06–1.34) | 0.003 | 1.30 | (1.08–1.55) | 0.005 |
| Moderate (10–14) | 1.22 | (1.01–1.47) | 0.043 | 1.19 | (0.89–1.59) | 0.253 |
| Moderately severe (15–-19) | 1.38 | (1.04–1.82) | 0.025 | 1.48 | (0.99–2.22) | 0.055 |
| Severe (20–27) | 1.63 | (1.08–2.47) | 0.020 | 1.53 | (0.87–2.71) | 0.140 |
| Generalized anxiety (GAD-7) | ||||||
| Minimal (0–4) | reference | reference | ||||
| Mild (5–9) | 1.00 | (0.87–1.16) | 0.965 | 1.03 | (0.83–1.29) | 0.765 |
| Moderate (10–14) | 0.96 | (0.75–1.21) | 0.706 | 1.24 | (0.88–1.75) | 0.228 |
| Severe (15–21) | 0.86 | (0.60–1.23) | 0.402 | 1.28 | (0.78–2.10) | 0.331 |
| Fear of COVID-19 (FCV-19S) | ||||||
| No fear (7–15) | reference | reference | ||||
| Mild (16–20) | 0.86 | (0.77–0.96) | 0.006 | 0.50 | (0.42–0.59) | < 0.001 |
| Moderate (21–25) | 0.90 | (0.80–1.02) | 0.094 | 0.47 | (0.39–0.56) | < 0.001 |
| Severe (26–35) | 0.74 | (0.62–0.87) | < 0.001 | 0.41 | (0.31–0.53) | < 0.001 |
Boldface indicates statistical significance at the 5% level (both sides). Estimates are RRRs derived from multinomial logistic regression analyses adjusting for all of generalized trust, PHQ-9, GAD-7, and FCV-19S, plus other explanatory variables (sex, age group, level of education, family members living together, employment, annual household income, bank and saving deposit amount, BMI, pre-existing conditions, and region of residence). All explanatory variables are those at wave 1. Willingness to be vaccinated at wave 3 was the outcome reference group
RRR Relative Risk Ratio, CI Confidence Interval, PHQ-9 Patient Health Questionnaire-9, GAD-7 Generalized Anxiety Disorder −7, FCV-19S Fear of COVID-19 Scale