2. Materials and Methods
2.1. Aims
Firstly, we have analyzed emotional intelligence skills in relation to sex and age differences in patients undergoing chronic HD therapy. Secondly, we have studied quality of life of HD patients according to sex. Finally, we have described the correlation factors associated with emotional intelligence.
2.3. Study design
A descriptive, observational, cross-sectional, analytical, multicentre study was conducted [
35] to determine the factors that affect quality of life in chronic HD patients as well as differences by age and sex.
2.4. Participants
The study was directed at all 297 patients included in the chronic HD program of a region of Catalonia (Spain) in a convenience sample of four HD centres which presented similar characteristics. The inclusion criteria required patients to be older than 18 years of age, attend one of the four different HD units, and voluntarily agree to participate. Patients who suffered from mental disorders or a clinical condition at the time of data collection and those with language barriers were excluded. After applying the above criteria, a total of 138 patients were eligible to answer the self-assessment questionnaires (46.5%).
2.5. Data Collection
Initially, permission to contact the patients was requested from the clinics or hospital direction as well as from the medical and nursing supervision members at the hemodialysis units. We informed not only the patients but also the professional members of the hemodialysis units about the purpose of the study, including confidentiality and voluntary participation. Data collection was undertaken during the time of HD therapy and paper format questionnaires were handed out to be answered in situ. Some patients requested to answer them at home due to physical difficulties, such as needle insertions or not carrying reading glasses at the time of HD therapy, and these questionnaires were returned on the next session.
2.6. Variables
The independent variables used to explain variations in quality of life were sociodemographic variables (sex, age, living situation and level of education). Emotional Intelligence was a modulating variable for quality of life. The dependent variables were those related to quality of life such as physical and mental dimensions.
2.7. Instruments
The participation ad-hoc questionnaire designed for sociodemographic data collection included the following variables: age and sex; level of studies (primary, secondary and university); living situation (alone, nursing homes, lives with family); employment status (employed, unemployed, retired, other situation); and monthly income (above or below €645, based on the Spanish minimum standard salary in 2016).
We assessed Emotional Intelligence with the Trait Meta-Mood Scale (TMMS-24) [
15], Spanish translation and validation [
36]. It is a self-report measure designed to assess individual’s beliefs about their own emotional abilities. This scale addresses three key aspects of perceived emotional intelligence:
Attention conveys to what extent individuals tend to observe and think about their feelings and moods;
Clarity evaluates the understanding of one’s emotional states, and
Repair refers to the individual’s beliefs about their ability to regulate their feelings. Specifically, the TMMS-24 is a 24-item Likert-type scale on which participants are required to rate the extent to which they agree with each item on a 5-point scale with anchors of 1=strongly disagree and 5= strongly agree. The scale appeared to have adequate psychometric characteristics with high reliability (Cronbach Alpha: perception α=0.90; clarity, α=0.90, repair α=0.86) (test-retest reliability: perception=0.60, clarity=0.70, repair=0.83) [
37]. The score on the different factors was obtained from the sum of the set of items on each scale. Items 1-8, 9-16, and 17-24 evaluated emotional attention, clarity, and repair correlatively. Based on these scores, participants were classified as: “need to improve”, “adequate” or “excellent” in emotional clarity/repair and “need to improve”, “adequate” and “too much” in emotional attention. This classification was made using different cut-off points for males and females as, according to the authors, there are sex differences in the handling of emotions.
Quality of life was measured with the Kidney Disease Quality of Life-Short Form questionnaire (KDQOL-SF) [
38]. It consists of the generic 36-Item Short Form Health Survey (SF-36) [
39] as well as 11 multi-item scales focusing on quality of life issues specific to patients with kidney disease. The generic survey consists of 8 scales that can provide two summative scores: physical and mental summative index. The internal consistency of the generic part is strong, alpha values range from .78 to .92 [
40]. The questionnaire is completed with 44 specific items of kidney disease distributed on 11 scales. For the present research, one item was removed because it only referred to patients undergoing peritoneal dialysis. The specific part of the questionnaire had a high internal consistency with a Cronbach’s alpha α = .80 (with 2 exceptions α = .68 in cognitive function and α = 0.61 as social interaction). The average values of the objective scales oscillated between 25.6 (DT = 37.82) in work and 79.11 (DT = 19.75) in cognitive function in the percentage of possible total score (0 - 100). This instrument is the most used internationally because it assesses patients with kidney failure in a holistic way [
41].
2.8. Statistical analysis
Statistical analysis was performed using Windows SPSS software, version 25.0 for IBM. Continuous variables were described as the mean and standard deviation or the median and interquartile range, according to their probability distribution. Continuous variables were compared with the Student’s t-test or with a one-way ANOVA and the categorical variables with the Chi-square test. A linear regression model was carried out to study the factors related to quality of life. The variables accepted for the lineal regression analyzes were the ones associated to emotional intelligence in the bivariant analysis. In all cases, a p-value < 0.05 was considered statistically significant.
2.9. Ethical considerations
This research study has complied with the fundamental ethical principles that govern the conduct of research. The anonymity of the participants was guaranteed at all times, and the informed consent form was signed by all participants prior to the start of data collection. The study was approved by the Ethics Committees of Clinical Research of the area of influence (acceptance number: 2014.016 date: 24/02/2014 act #3).
3. Results
3.1. Study sample characteristics
Participant demographics showed that there was a total of 138 participants of whom 89 were men and 48 were females (64.5%-35.5%). In relation to level of education, 76.8% of all participants had primary studies and only 5.1% university level. Nine out of ten participants lived with family and had an employment status of retirement, in greater proportion in males than in females (p=0.009). In terms of household income, we can underline that more than two thirds of males had a higher income than females (p=0.029)
In relation to the participants’ clinical characteristics, the mean hemodialysis time was 54.4 months (4.5 years) and a median of 36 [IQR 12-72] in males. In females, the mean hemodialysis time was 56.5 months (4.7 years) and a median of 42 [IQR 23-72] (p= 0.415). The hours of hemodialysis per session in males and females were 3.9 and 3.8, respectively (p=0.004). The number of hospitalizations over the last 3 months was 0.16 in males and 0.08 in females (p= 0.104).
3.2. Emotional Intelligence in chronic hemodialysis patients
Table 1 shows the descriptive values of the three dimensions of Emotional Intelligence, split by sex, because males and females had different reference values. The highest scores in males were in Clarity followed by Repair and finally in the Attention dimension. In females, the highest scores were firstly in Repair, followed by Clarity and finally in Attention.
Figure 1 and
Figure 2 show the classification of emotional intelligence in males and females. As we can observe in
Figure 1, the largest proportion of male participants scoring “Excellent” were in the Clarity dimension. Of those scoring “Adequate”, the largest percentage were in the Repair dimension. In females (
Figure 2), however, the largest proportion of participants scoring “Excellent” were in the Repair dimension followed by Clarity, and a high proportion in Attention were in “Need to improve” (67.3).
When comparing emotional intelligence according to age groups in males, we observed that Attention, mean=24.1 (7.5), and Clarity, mean= (6.8), were higher in participants older than 64 years old. On the other hand, in terms of Repair, mean=28.3 (8.8), the highest scores corresponded to 46 to 65 year-old participants. However, there was no significant statistical differences between males according to age groups.
In females, the 25 to 45-year-old age group presented the highest scores in Attention, mean=29 (9.3), and Clarity, mean=31.3 (74). In the Repair dimension, the groups between 25 to 45 and 46 to 65 years of age had similar scores of 30.3 (7.8) and 30.6 (6.4), respectively, without significant statistical differences between females according to age groups.
3.3. Quality of life in chronic hemodialysis patients
With a general overview of the results obtained regarding the physical dimensions of quality of life, we can note that scores were low. The four physical dimensions of quality of life are shown in
Table 2. There were significative differences in age groups where younger participants had a better score in all the physical functions than older participants (p=0.001). Moreover, those who had a higher level of education presented better physical function (p=0.027).
In relation to the mental dimensions of quality of life (
Table 3), males presented higher scores than females in the emotional role (p=0.045). Younger participants had higher scores in vitality (p=0.038). Finally, participants who had university studies presented higher scores in emotional wellbeing (p=0.036).
In the linear regression model used to study the variables associated with the perception of general health, no sociodemographic variables were observed or related to the three dimensions of emotional intelligence in males. However, Attention (p=0.046) and Repair (p<0.01) were found to be strongly associated with perception of general health in female (
Table 4 and
Table 5).
4. Discussion
This study analysed emotional intelligence skills and quality of life in a sample of 138 patients undergoing chronic hemodialysis therapy. In relation to emotional intelligence, we could observe major differences in the dimensions of emotional attention and repair. More females than males (+33.3%) had low attention. However, 27.2% more males had adequate attention compared to females and finally 5.3% more males paid too much attention to emotions compared to females. Results showed that 9% more females had excellent emotional repair compared to males. These contradicting results could be explained by the characteristics and the different emotional stages that chronic hemodialysis therapy represents. This contradicts other results reporting higher emotional intelligence skills in females in a healthy population [
42]. These differing patterns constitute an indication of a great sociodemographic diversity, as well as the progesterone phase of their menstrual cycle in young females could perform better on EI [
43] and we did not control this potential confounder. Pardeler et al., 2018 exposed that cognitive abilities need to be considered when assessing emotional intelligence in healthy individuals as sex differences are present [
44]. When analyzing EI as an ability-base approach rather than analyzing trait emotional intelligence, also appears that females have higher scores compared to males [
45].
Across the majority of emotion-related outcomes, trait emotional intelligence tends to be a stronger predictor and, consequently, O’Connor et al (2019) suggest that new users of emotional intelligence should consider using a trait-based measure before assessing alternatives (14). When using self-report measures, such as TMMS-24, sex differences in results are shown. Thus, males perceive themselves as more emotionally intelligent than females, so these measures demonstrate levels of emotional attention that are too high [
46].
We need to consider that negative emotions can have an impact and lead to higher emotional attention and clarity. Therefore, they enhance a state of anxiety, which is why it is relevant to achieve a balanced level of emotional intelligence in order not to suffer other disorders. Paying excessive attention to emotions can have detrimental effects, reducing the ability to regulate emotions [
47]. Multiple aspects of intelligence need to be controlled when assessing emotional intelligence for the prediction of health outcomes [
45].
When studying emotional intelligence by age, we can mention that our results were similar to the literature [
48] as the ability to repair increased with age. These results could be related to life experience as well as better emotional control.
The existence of a positive correlation between emotional intelligence and quality of life in chronic hemodialysis patients was shown in 2016 using a different instrument from TTMS-24 (25). Other studies showed no sex difference in terms of quality of life and emotional intelligence, marital status, and educational levels [
49].
As for emotional intelligence training, studies have shown great results in all dimensions. With a comparative study, there were significant correlations in the intervention group, obtaining statistically significant overall results: 42.00
+ 10.22 before the intervention and 58.24
+ 8.66 post intervention. Emotional Intelligence training has shown excellent results towards improving quality of life aspects, including reducing anxiety scores in HD patients [
26,
50]. Similar results exist in breast cancer patients where effective interventions such as physical activity and psychosocial interventions proved to have worthy outcomes [
51].
Our results regarding quality of life by sex and age differ a little from others in the literature, as a study conducted in Jordan on participants undergoing hemodialysis therapy showed that males and younger participants ones had a higher mental quality of life than female participants in general [
52]. The systematic review by Yapa [
53], where quality of life and symptoms experienced by patients who have CKD and are not on dialysis were analyzed, concluded that quality of life decreased when symptoms increased. Thus, evidence on how and which symptoms change over time was inconclusive. One possibility could be due to gender-related biological factors as well as different lifestyles, socialization, and culture norms [
23].
The study of quality of life in patients who suffer other chronic conditions is wide and results are similar. For example, Yalcin et al. (2008) demonstrated that higher emotional intelligence levels were related to a better quality of life and general well-being of people with diabetes [
54]. Moreover, the way that females with breast cancer regulate their emotions influences their quality of life and enhances disease adaptation [
55]. Emotional intelligence studies in patients who suffer from chronic obstructive pulmonary disease (COPD) showed an association with all domains of quality of life regardless of age [
56]. This suggests that, since emotional intelligence is a trainable skill, there is an opportunity to convert this knowledge into management programs in order to improve the quality of life and well-being of such patients. In this sense, it has also been observed in the present study a strong association between general health and emotional intelligence of females. These sex differences could be explained by different responses in processing emotional signals [
22] and the interrelation between cognitive abilities and the understanding of the emotions [
42].
This research is not without limitations. Firstly, the use of self-report measures is prone to recall bias. Secondly the cross-sectional design has not allowed causal associations, or the direction of the associations to be studied. Thirdly, since most questionnaires were completed during HD therapy, the presence of medical staff and other patients may have influenced the objectivity of the responses and threatened data validity. Finally, we used the term sex, which often refers to biological phenotype. However, there are studies that indicate that the differences are related in the experience itself rather than in gender identity [
23]. We believe that in future research on Emotional Intelligence, sex differences and gender identity should be considered separately.
This study has strengthened existing evidence that chronic HD therapy can have detrimental mental health effects in CKD patients. It has been proven that these negative health effects have an impact on patients’ wellbeing and quality of life and require effective measures in nursing practice to be developed and implemented.
A holistic view of CKD patients should be adopted by nephrology nurses in order to consider and care for different aspects of their suffering, including emotion management. Emotional intelligence is a promising protective factor for biological and psychological variables in populations who suffer a chronic condition [
57]. Likewise, renal association guidelines currently recommend health-related quality of life to be monitored in patients undergoing renal replacement therapy [
58].
We suggest that clinical practitioners treating chronic hemodialysis patients should assess levels of emotional attention, especially in females. If instability is detected, a complete psycho-emotional intervention should be conducted. Nurses have the capacity to establish a helping relationship and have at their disposal key resources to do so, for example, empowering hemodialysis patients to enhance their coping strategies [
59].
Finally, quality of life is one of the main concerns of policymakers and public health planners in the community as well as an indicator of quality care. We aim to contribute to this knowledge with the present research.