. Author manuscript; available in PMC: 2022 Aug 1.

Published in final edited form as: Am J Prev Med. 2021 May 18;61(2):e53–e61. doi: 10.1016/j.amepre.2021.02.011

Table 3.

Relative Risks for the Joint Exposure of Purpose in Life and Wealth (N=13,159)^a

	Sense of purpose in life^b								Additive and multiplicative effect modification
	Low		Medium–low		Medium–high		High		Low	Medium–low		Medium–high		High
Wealth quintiles^c	n, died/alive	RR (95% CI)	n, died/alive	RR (95% CI)	n, died/alive	RR (95% CI)	n, died/alive	RR (95% CI)		Additive^d	Multiplicative^e	Additive	Multiplicative	Additive	Multiplicative
1st quintile	389/592	1.0	207/451	0.93 (0.78, 1.10); p=0.40	170/402	1.00 (0.83, 1.20); p=0.98	84/330	0.81 (0.64, 1.03); p=0.08	ref	ref	ref	ref	ref	ref	ref
2nd quintile	2,990/504	0.94 (0.81, 1.10); p=0.45	166/483	0.82 (0.68, 0.99); p=0.04	156/470	0.82 (0.67, 0.99); p=0.04	900/422	0.66 (0.53, 0.84); p<0.01	ref	−0.05 (−0.28, 0.18); p=0.68	0.94 (0.73, 1.21); p=0.63	−0.12 (−0.378, 0.13); p=0.33	0.87 (0.67, 1.13); p=0.29	−0.09 (−0.36, 0.18); p=0.52	0.87 (0.62, 1.22); p=0.42
3rd quintile	234/430	0.89 (0.75, 1.05); p=0.18	164/456	0.81 (0.67, 0.98); p=0.03	142/555	0.77 (0.63, 0.94); p=0.01	88/539	0.66 (0.51, 0.80); p<0.01	ref	−0.01 (−0.25, 0.22); p=0.90	0.97 (0.75, 1.26); p=0.84	−0.12 (−0.37, 0.13); p=0.34	0.86 (0.66, 1.13); p=0.29	−0.06 (−0.33, 0.20); p=0.63	0.88 (0.63, 1.23); p=0.46
4th quintile	172/361	0.85 (0.70, 1.03); p=0.09	155/515	0.78 (0.64, 0.95); p=0.01	142/638	0.71 (0.57, 0.87); p<0.01	88/640	0.57 (0.45, 0.73); p<0.01	ref	0.00 (−0.24, 0.24); p=0.99	0.99 (0.75, 1.30); p=0.92	−0.15 (−0.40, 0.11); p=0.27	0.83 (0.62, 1.11); p=0.21	−0.09 (−0.36, 0.19); p=0.54	0.83 (0.59, 118); p=0.31
5th quintile	165/299	0.95 (0.78, 1.16); p=0.64	109/461	0.68 (0.54, 0.86); p<0.01	108/676	0.55 (0.44, 0.69); p<0.01	108/682	0.63 (0.50, 0.80); p<0.01	ref	−0.20 (−0.46, 0.06); p=0.13	0.77 (0.57, 1.03); p=0.08	−0.40 (−0.68, −0.13); p<0.01	0.58 (0.43, 0.78); p<0.01	−0.13 (−0.41, 0.15); p=0.36	0.82 (0.58, 116); p=0.24

Notes: Boldface indicates statistical significance (p<0.05).

Risk ratios were adjusted for age, gender, race/ethnicity, marital status, education, household income, health insurance, heart disease, stroke, cancer, diabetes, hypertension, lung disease, arthritis, and depression using Poisson regression.

Purpose in life was assessed using the purpose in life subscale of the Ryff Psychological Well`being Scales. Purpose in life quartiles: low: 1.00–3.86; medium–low: 3.87–4.57; medium–high: 4.58–5.29; high: 5.30–6.00.

Wealth quintiles: 1st quintile: ≤$35,000; 2nd quintile: $35,001–$140,000; 3rd quintile: $140,001–$311,000; 4th quintile: $311,001–$652,500; 5th quintile: ≥$652,501.

Effect modification on additive scale: relative excess risk due to interaction (RERI; SEs were calculated by using delta method).

Effect modification on multiplicative scale: ratio of risk ratios (RRR).

RR, risk ratio.