Divorce is an unfortunate, stressful but unavoidable circumstance for families, children, and society [1]. Divorce rates have steadily increased over recent years [2] and are undoubtedly influenced by many factors, but marital satisfaction is the most influential [3,4]. Marital satisfaction is a multidimensional concept comprised of diverse aspects of marital relationships but spouse satisfaction is presumably the most important. Although researchers have investigated the influences of a wide range of factors on marital satisfaction, little information has been published on the effect of age disparity (seniority or juniority) between couples. However, one Australian study indicated that both husbands and wives tended to be more satisfied with younger spouses [5].

As populations age globally, the dynamics within marriages involving older adults have gained increasing attention. Age disparity can significantly impact the health outcomes and quality of life for older spouses, necessitating a deeper understanding of its effects on marital satisfaction. Older spouses in age-discrepant marriages face unique challenges such as differing health needs, caregiving expectations, and life stage goals. Furthermore, the burden of caring for an older partner with declining health can strain marital relationships and reduce satisfaction [6]. Therefore, examining how age differences influence marital satisfaction in older adults can provide valuable insights for developing supportive interventions.

In accord with Confucian culture, Korean husbands are traditionally older than wives and take full responsibility for households, though this practice is undergoing rapid change due to the weakening of traditional patriarchy [7]. Today, many younger Korean women are economically active and focus on career advancement, and as a result, delay marriage and subsequently choose younger husbands [8]. Sex roles are a social construct, but occasionally individuals display characteristics beyond accepted sex norms, and these can cause conflicts that impact interpersonal relationships, especially spouse satisfaction [8,9]. More specifically, inherent value conflicts and power imbalances within families can lead to spouse dissatisfaction when a wife is older than her husband. Given cultural differences on this issue [10], we undertook this study to investigate the association between age disparity between couples and spouse satisfaction using a nationwide representative Korean database.

1. Design and participants

Data from the Korean Longitudinal Study of Aging (KLoSA), a nationwide survey of community-dwelling people at least 45 years of age, was collected by multistage stratified cluster sampling, was used in the present study. The KLoSA has been conducted biennially by the Korea Labor Institute since 2006 with the aim of developing and implementing social and economic policies that effectively address population aging. We selected data from the most recent KLoSA study (the 7th wave); 4,498 individuals with a living spouse were initially included. However, 204 patients with a psychological disorder were excluded, and thus, the data of 4,294 individuals were included in the final analysis. Ethical approval for this study was obtained from the Institutional Review Board of the Gil Medical Center (registration no., GFIRB2021-412).

2. Measurements

Participants were allocated to a similar group (age gap ≤1 year), an older husband group, or an older wife group based on age disparity. Satisfaction was assessed using 5 questions (total response score range, 0-100): “to what extent are you satisfied with i) your wealth, ii) health, iii) relationship with your spouse, iv) relationship with your offspring, and v) your overall standing as compared with your contemporaries?”

Covariates included demographics (age, age disparity, sex, average household income, educational attainment, religious affiliation, and current job), health-related habits (obesity, smoking and drinking status, and regular physical activity), comorbidities (hypertension, type 2 diabetes, and cardiovascular diseases), and mental health (levels of social contact and depressive mood). Education levels were categorized as “less than middle school graduate” or “high school graduate or higher”. Income levels were stratified about median annual household incomes. Obesity was defined as a body mass index of 25 kg/m² or higher. Smoking was categorized according to current use and drinking according to overuse. Regular physical activity was defined as exercise more than once per week. Social contact was assessed using the question, “do you have a person who you regard is close to you (i.e., a friend, relative, or neighbor)?” Depression was assessed using the short-form of the Center for Epidemiological Studies-Depression scale [11], which is a brief screening instrument that addresses depressive symptoms experienced during the previous two weeks. This 10-item scale includes two positively phrased items (i.e., feel pretty good, generally satisfied) and eight negatively phrased items (i.e., loss of interest, trouble concentrating, feeling depressed, feeling tired or low in energy, feeling afraid, trouble falling asleep, feeling alone, and hard to get going). Each item is scored from 0 to 2 and higher scores indicate greater depressive symptoms. We used a standard cutoff score of 10 to categorize individuals that experienced depressive moods [12].

3. Statistical analysis

Although we were aware of potential sex differences in perspectives of partner satisfaction, we were unable to investigate this topic due to the small size of the older wife group. Descriptive statistics are presented as means±standard deviations or numbers (percentages), as appropriate. Multivariate regression models were used to identify factors associated with spouse satisfaction. The statistical analysis was conducted using STATA software (version 14.2; STATA Corp, College Station, TX, USA). Statistical significance was accepted for two-tailed P-values of <0.05.

Approximately three-quarters of 4,294 study subjects were allocated to the older husband group (20% to the similar group and 5% to the older wife group). Table 1 presents the characteristics of participants by group. The older wife group contained more female, and they were more likely to be poor, to have a low education level, and to have no current job. Notably, members of the older wife group were less satisfied with their spouses than those in the other two groups (P=0.009).

Table 1 . Characteristics of participants by age disparity between couples.

	Similar* (n=848)	Older husband (n=3,240)	Older wife (n=206)	P-value†
Demographics
Age (yr)	68.6±8.9	69.3±8.3	69.6±8.7	0.058
Age gap from the partner	-	4.9±2.8	2.5±4.2	<0.001
Female	381 (44.9)	1,557 (48.1)	146 (70.9)	<0.001
Low income	359 (42.3)	1,490 (46.0)	104 (50.5)	0.041
Low education	392 (46.2)	1,720 (53.1)	135 (65.5)	<0.001
No religion	546 (64.4)	2,015 (62.2)	134 (65.0)	0.382
No current job	451 (53.2)	1,999 (61.7)	131 (63.6)	<0.001
Health-related habits
Obesity	203 (23.9)	773 (23.9)	58 (28.2)	0.343
Current smoking	98 (11.6)	309 (9.5)	23 (11.2)	0.186
Over drinking	46 (5.4)	126 (3.9)	9 (4.4)	0.140
No regular exercise	545 (64.3)	2,065 (63.7)	144 (69.9)	0.201
Comorbidities
Hypertension	376 (44.3)	1,394 (43.0)	104 (50.5)	0.101
Type 2 diabetes	151 (17.8)	653 (20.2)	33 (16.0)	0.134
Cardiovascular diseases	112 (13.2)	436 (13.5)	23 (11.2)	0.641
Mental health
No social contact	160 (18.9)	616 (19.0)	50 (24.3)	0.170
Depressed	70 (8.3)	288 (8.9)	24 (11.7)	0.307
Satisfied with (range, 0-100)
Own health	59.7±19.1	59.0±19.3	57.0±19.3	0.187
Current wealth	57.7±18.6	57.4±18.3	55.0±19.7	0.139
Offspring	71.6±14.4	71.5±14.4	70.3±12.9	0.680
Spouse	68.5±15.7	67.6±15.3	64.8±15.2	0.009
Overall	64.3±16.1	64.3±15.5	61.6±16.9	0.050

Data are presented as means±standard deviations or numbers (%). -, not applicable. *Age gap ≤1 year. ^†As determined by one-way analysis of variance or the χ² test, as appropriate..

Factors found to be associated with spouse satisfaction are summarized in Table 2. The older wife group had significantly lower spouse satisfaction scores than the similar group in the crude (P=0.002) and age-/sex-adjusted (P=0.041) models, but this significance was lost in the multiple-adjusted model (P=0.265). Factors found to be significantly related to high spouse satisfaction were young age, male sex, non-depressed state, and satisfaction with other domains (i.e., health, wealth, and offspring).

Table 2 . Factors associated with spouse satisfaction.

	Unadjusted (n=4,294)			Age- and sex-adjusted (n=4,294)			Multiple†-adjusted (n=2,135)
	ß (95% CI)	P-value		ß (95% CI)	P-value		ß (95% CI)	P-value
Older husband (vs. similar)	–0.91 (–2.08-0.25)	0.124		–0.57 (–1.72-0.57)	0.328		–0.11 (–1.90-1.67)	0.900
Older wife (vs. similar)	–3.66 (–6.00-–1.32)	0.002		–2.42 (–4.73-–0.10)	0.041		–1.53 (–4.23-0.16)	0.265
Younger age (per 1-year)	-	-		-	-		0.10 (0.02-0.18)	0.013
Male sex	-	-		-	-		4.17 (2.89-5.44)	<0.001
Non-depressed*	-	-		-	-		3.75 (1.72-5.78)	<0.001
Satisfaction (per point)
Health	-	-		-	-		0.06 (0.02-0.10)	0.002
Wealth	-	-		-	-		0.18 (0.15-0.22)	<0.001
Offspring	-	-		-	-		0.53 (0.49-0.57)	<0.001

ß, regression coefficient; CI, confidence interval; -, not applicable. *As determined by Center for Epidemiological Studies-Depression scores. ^†Adjusted for demographics (age, age gap, sex, educational attainment, income levels, and religion), health-related habits (obesity, smoking and drinking status, and regular physical activity), comorbidities (hypertension, type 2 diabetes, and cardiovascular diseases), mental health (social contact and depressive mood), and satisfaction (for health, wealth, and offspring)..

The family unit is the cornerstone of all societies, and this is especially the case in Southeast Asian countries including Korea. Obviously, marital satisfaction plays a significant role in the stability of this social unit, and thus, identifying factors that significantly impact spouse satisfaction is of considerable importance. However, few have examined the effect of age heterogamy on marital satisfaction [5,13], and studies on the effect of age disparity between couples are scarce. In this study, we examined the relationship between seniority and spouse satisfaction in a nationally representative sample of the South Korean general population. The results demonstrated that seniority between couples is not associated with spouse satisfaction, and that spouse satisfaction might be influenced by other factors, such as age, sex, depression, and satisfaction with others.

With the ongoing aging of populations, understanding marital satisfaction among older couples becomes increasingly important due to its implications for health and well-being. Our study confirmed the effect of age and sex on spouse satisfaction. Husbands were more satisfied with spouses than wives, which is consistent with previous studies on Koreans [14,15] and other Asians [13,16]. Family life is relatively stressful in Korea, particularly for married female. According to the Korean Statistical Information Service [17], 75.9% of married male in Korea are satisfied with their spouses, whereas only 62.4% of married female are satisfied with their hushands. However, few studies have specifically examined the effects of age on reports of marital satisfaction among older adults [18]. Whereas some Western researchers have reported a U-shaped relationship between marriage duration and marital satisfaction [5,19], the significant decline in marital satisfaction with age observed in this study indicates prospective study is needed to further explore this phenomenon.

The present study identified some factors critically associated with spouse satisfaction, that is, depressive mood and satisfaction with other factors (i.e., wealth, health, and offspring). It is particularly pertinent for older adults, as age-related health challenges an evolving family dynamic can exacerbate depressive symptoms, further affecting marital satisfaction. While a negative relationship between depressive symptoms and marital satisfaction is not surprising [20], it is noteworthy that satisfaction with others, particularly with offspring, was found to have a substantial impact on spouse satisfaction. In Korea, spouses and offspring are the two major sources of happiness or distress, especially as individuals age and familial role shift.

The limitations of this preliminary study must be addressed by future research. First, the use of an existing database was too imprecise. A single item was used to measure spouse satisfaction, and other relevant aspects of relationships may have been overlooked. Multi-item scales of more elaborate constructs, such as communication, in-law relationships, family functioning, and individual personalities [8,21], would have provided more detailed description of relationships. Second, we did not explore the possibility of reverse causality for time-dependent covariates (e.g., depression) [22]. Third, the study population was restricted to married individuals, and thus, divorced individuals were not included. In addition, as sex roles are culturally and context-based, further dyadic research is needed in other ethnicities, and ideally, participants should be followed prospectively regardless of divorce.

Despite its limitations, this is the first study to examine the effect of seniority/juniority on spouse satisfaction among Korean married couples. Although seniority/juniority was not found to influence spouse satisfaction, we did find that several other factors exhibited significant associations. We suggest that these factors, especially those relevant to the health of older adults, be specifically addressed during marital counseling.

In conclusion, this study explored the relationship between age disparity and spouse satisfaction among married Korean older adults using a nationally representative sample. Contrary to common assumptions, our findings revealed that age differences between spouses do not significantly affect overall marital satisfaction. However, other factors such as depressive symptoms, individual health, and satisfaction with offspring were found to play crucial roles in influencing spouse satisfaction. These insights highlight the complex interplay of personal and relational dynamics that contribute to marital satisfaction in older adults, underscoring the need for tailored approaches in marital counseling and healthcare interventions. Future research should continue to investigate these relationships longitudinally and in diverse cultural contexts to further enhance our understanding of the factors that sustain marital satisfaction as couples age.

This research was supported by Gachon University Gil Medical Center under Grant FRD2021-14.

YJ Lee is an editorial board member of the journal but was not involved in the peer reviewer selection, evaluation, or decision process of this article. No other potential conflicts of interest relevant to this article were reported.

The authors wish to thank Yeyoung Park (McLean High School) for her assistance in correcting and editing English in the manuscript.