Background
In the US, cancer is the second leading cause of death after accidents in the infant population aged 5 to 14. Ten thousand cases of infant cancer were diagnosed in 2017, representing 1% of diagnosed cancer cases [
1]. The types of cancer common in infant populations are acute lymphoblastic leukemia (26%), brain and central nervous system tumors (21%), neuroblastoma (7%) and non-Hodgkin lymphoma (6%) [
2]. The prevalence of cancer in the US infant population is higher in white and Hispanic ethnic groups. Due to advances in treatment, the 5-year survival rate for children diagnosed with cancer is greater than 80% [
2].
In Mexico, child cancer is a public health problem and is the leading cause of death in children aged 5 to 14. Five thousand cases of childhood cancer are diagnosed annually in Mexico, representing 5% of diagnosed cancer cases [
3]. The 5-year survival rate of children diagnosed with cancer in Mexico is 56%. Approximately 75% of cancer diagnoses in Mexico are performed in advanced stages of the disease [
3]. The most common types of childhood cancer in Mexico are acute lymphoblastic leukemia, acute myeloblastic leukemia, non-Hodgkin lymphoma and Hodgkin disease [
3].
Children with a diagnosis of cancer represent one of the greatest challenges for family environments, with physical, psychological, socioeconomic, and behavioral effects on patients and their caregivers. These effects translate into vulnerability and a decline in families’ quality of life and functioning [
4]. However, despite adversity, families and caregivers of pediatric patients can adapt to the diagnosis and medical treatment crises [
5]. Families that adapt are proactive, gather information, find resources, form cooperative and support networks with medical personnel, and establish social relations [
6].
In this context, resilience plays a central role in addressing and overcoming disease. Because there are psychosocial factors related to caregiver burden among families of children with chronic conditions, including sociocultural historical premises, parental stress, anxiety, social support networks, family support, family functioning, well-being and sociodemographic characteristics, these variables influence the processes of resilience of families facing adversity, risk and vulnerability during a child’s disease [
7].
Family-focused studies on resilience help in understanding the risks and protective processes involved in attaining positive development in contexts of adversity [
8]. Research shows that especially when parents are motivated to change, cooperate with health professionals, and communicate the effects of treatment to their children, a favorable prognosis for the disease is fostered and idiosyncrasies in the family’s progression and resilience are reduced [
9].
While measurement constructs related to resilience are of paramount methodological importance, several authors highlight specific challenges and shortcomings in this area. For example, Windle et al. [
10] conducted a systematic review of 19 scales focused on the resilience resources of individuals and found that most of these scales lacked information regarding psychometric properties and required additional validation. At the time, the best-rated scales included the Connor-Davidson Scale, the Resilience Scale for Adults, and the Brief Resilience Scale. Additionally, the need for effective instruments that assess strengths, protective processes, and outcomes based on these resilience resources in the context of pediatric disease is well acknowledged [
11].
Empirical findings have been reported based on assessment instruments created mainly in Europe and the United States, but extrapolating the results of their implementation to other contexts and cultures is challenging [
10]. In response to this situation, Palomar and Gómez created the Mexican Scale of Resilience (RESI-M) [
12]. The RESI-M is based on the Connor-Davidson Resilience Scale [
13] and the Resilience Scale for Adults [
14].
From the combination of these two scales, Mexican researchers defined five factors based on a principal component analysis with a Varimax rotation and determined the number of factors through the Kaiser criterion. The first factor of personal competence is characterized by the conviction that one is sufficiently prepared to be able to face any situation that arises, even if it is unexpected. The second factor comprises the features of self-confidence, tolerance to negative situations, and the ability to strengthen oneself when faced with the effects of stress. The third factor concerns secure relationships and acceptance of change, or the ability to establish personal relationships of support and personal development as well as the ability to flexibly adapt to new situations. The fourth factor, named control, is characterized by the ability to promote one’s well-being and to conduct oneself according to what one wants or plans. The five factors of spiritual influence are characterized by the positive effect that spiritual beliefs and practices have on the person.
Resilience to disease is a process of positive adaptation despite the loss of health, it involves the development of vitality and skills to overcome the negative effects of adversity, risks, and vulnerability caused by disease [
15]. The existence of a scale in Spanish that enables the measurement of resources for resilience to cancer in childhood and that has had sufficient analysis of its psychometric properties may extend the research conducted with family caregivers of children with chronic disease. In addition, this assessment instrument can contribute significantly to the development and evaluation of intervention programs aimed at families to help overcome adversity in the face of disease.
In a sample of 446 Mexican family caregivers of children with different chronic diseases, the factor validity and internal consistency of the RESI-M was studied [
15]. The expected five-factor model showed a close fit to the data through maximum likelihood estimation, χ
2/df = 1.66, CFI = .95, and RMSEA = .03 (90% CI: .02, .04). The internal consistency for each factor using Cronbach’s alpha ranged from .76 to .93, and the overall internal consistency was .95. No average difference in the RESI-M and its factors was found between women and men [
15]. This validation study did not use methods designed for ordinal variables (Likert-type items), such as the ordinal alpha, polychoric correlation matrix, and free-scale least squares methods. The distribution and convergent/divergent validity of the RESI-M were not studied.
The RESI-M has also been validated in a sample of 120 Mexican women with cancer [
16]. The internal consistency value for the scale was very high, Cronbach’s alpha = .96, and the internal consistency the factors ranged from very high, .93, to high, .82. The 5-factor model showed a close fit to the data when items 2 and 15 were eliminated. Fit indexes through unweighted least squares estimation were Bollen-Stine bootstrap probability = .072, GFI = .968, AGFI = .963, NFI = .960, and RFI = .957 [
16]. The distribution of the scale or the factors did not adjust to a normal curve. In this study, neither the ordinal alpha nor the polychoric correlation matrix was used.
In a sample of 348 healthy Mexican adults (235 women and 113 men), the factorial weights pattern was reproduced through component analysis with 43.60% of the variance of the indicators explained by the five factors. The overall internal consistency was very high (Cronbach’s alpha = .92), and the internal consistency values for the factors were high (.86 to .83), except for the Structure factor, which had low internal consistency (Cronbach’s alpha = −.59) [
17].
A negative correlation between depression and anxiety and stress and resilience has been reported using the RESI-M [
18], but its relationship with social desirability has not been studied. Social desirability is a potential bias that can be present in the evaluation of traits [
19].
Given the need for an assessment instrument to measure resilience among family caregivers of children with cancer and the methodological background of validation studies with the RESI-M in Mexico, the objectives of this research are as follows: 1) calculate the internal consistency through ordinal alpha; 2) contrast factorial construct validity, verifying the convergent and discriminant validity of five RESI-M factors, from polychoric matrix through free-scale least squares estimation; 3) describe the distribution of scores in the RESI-M and its five factors; 4) compare the means between the factors; 5) evaluate the relation of the RESI-M total score and its factors with the sociodemographic variables of educational level, age and sex; and 6) test the convergent validity with respect to psychological well-being, the divergent validity with respect to depression, anxiety and parental stress, and the independence in relation to social desirability.
In correspondence with the proposed objectives, the hypotheses are as follows: 1) very high overall internal consistency [
12,
15‐
17] and from very high to acceptable internal consistency for the factors [
12,
15,
16]; 2) a five-factor model with convergent and discriminant validity in its factors (strength/self-confidence, social competence, family support, social support, and structure) [
12,
15‐
17]; 3) normal distribution in the RESI-M total score due to assessing a personality trait [
20], although its factors may show asymmetry [
16,
17]; 4) the higher the level of resilience, the higher the educational level and age [
12,
21,
22], and greater resilience in women than men [
12,
22‐
24], although sociodemographic variables are usually independent of resilience [
15,
16,
24]; 5) the highest means in family and social support and the lowest mean in structure [
16], and 6) positive correlation with psychological well-being [
14], negative correlation with depression, anxiety and parental stress [
18], and independence or low correlation with social desirability.
Discussion
The first stated objective was to calculate the internal consistency of the total score of the RESI-M and its factors. According to the expectations, very high overall internal consistency was obtained [
12,
15‐
17]. The five factors showed internal consistency values from very high to acceptable, as in other Mexican studies [
12,
15,
16]. Among the family caregivers of children with cancer in the present study, no factor had low internal consistency, including the structure factor, which had low internal consistency in another study conducted in Mexico among healthy adults [
17].
The second objective was to contrast a five-factor model and examine convergent and discriminant validity in the factors. In agreement with the expectations [
12,
15‐
17], the model showed a close fit to the data and was highly parsimonious. The factors of family support and social support met the criteria for convergent and discriminant validity. The three other factors showed adequate convergent validity because their AVEs were higher than .40 and their composite reliability was higher than .70. The criteria for discriminant validity were fulfilled for five factors, except for the distinction between social competence and structure. The structure factor showed the weakest convergent and discriminant validity properties, in line with our expectations [
12,
15‐
17].
The third objective was to describe the distribution of scores in the RESI-M and its five factors. In line with the expectation of assessing a personality trait [
20], the distributions of the total score and the social competence factor followed a normal distribution. The factors of strength/self-confidence and structure had a unique modal value, their measures of central tendency were very close, and both showed symmetry in their tails, with a slightly flattened form in the first and a slightly peaked form in the second. Therefore, their distributions approached normal. The distributions of family support and social support showed negative asymmetry (with a mass of the distribution more concentrated on the right of the arithmetic mean) and had a more acute peak around the arithmetic mean and fatter tails, moving away from a bell-shaped curve. Greater normality was found in the present sample than in previous studies [
16,
17]. The distributional characteristics of the support factors could be attributed to the cultural aspects of familism and collectivism [
39]. Most of the participants reported receiving considerable support from family and friends.
The fourth objective was to compare the means between the factors. According to the expectations [
16], the means of family support, social support and strength/self-confidence had the highest values (without significant differences among the three means). The means of social competence and structure had the lowest values (without significant differences between the two means). There were significant differences between the means of the two groups.
To assess the level of resilience among family caregivers of children with cancer in this study, we can divide the continuous range of scores in the RESI-M and its five factors (1 to 4) into four intervals of constant amplitude ([maximum value-minimum value]/number of values = [4-1]/4 = 0.75) in correspondence with the four ordinal values of the response to the items. In this way, response labels to the items can be used to interpret the scores and measures of central tendency: 1 to 1.749 → 1 = “strongly disagree”, 1.75 to 2.49 → 2 = “disagree”, 2.5 to 3.249 → 3 = “agree”, 3.25 to 4 → 4 = “totally agree”. Following this interpretive approach, the measures of central tendency (means, medians and modes) of the family support factor, in the interval between 3.25 and 4, corresponded to “totally agree” (4), and the measures of the central tendency of the total score of the RESI-M and its four remaining factors, in the interval between 2.5 and 3.249, corresponded to “agree” (3). Therefore, the participants reported a high level of resilience.
The arithmetic mean of the total RESI-M score of the present study, M = 132.715, 95% CI (130.967, 134.463) in a range of 43 to 172, was statistically equivalent, t(774) = − 0.514,
p = .607 assuming equality of variances through Fisher’s test: F(445, 329) = 1.076,
p = .240, to the one reported by Toledano-Toledano et al. [
15] among 446 Mexican adults with children with chronic diseases, M = 133.330, 95% IC (131.772, 134.888). Nevertheless, the mean of the present study was significantly lower, t(448) = − 13.019,
p < .001, assuming equality of variance through Fisher’s test, F(119, 329) = 1.017,
p = .446, than the one reported by Miaja and Moral [
16] among 120 Mexican women with cancer, M = 155.167, 95% CI (152.225, 158.109). Therefore, the level of resilience in women with cancer is greater than that in family caregivers of children with cancer. Two other studies in Mexico [
12,
17] did not report the arithmetic means of the total RESI-M score and its factors, so we cannot make comparisons.
The fifth objective was to evaluate the relationship with the sociodemographic variables. We expected that the level of resilience would be greater in persons with higher educational levels, older age and female sex [
12,
21‐
23]. This expectation was supported in relation to educational level; in accordance with previous studies, the strength of the association was low [
12,
21,
22]. The relationship with age was very low: the greater the age, the greater the level of structure, according to our expectation [
12,
21‐
23]. Older adults have more rules and routines that make it easier for them to maintain organization and order in their lives. However, sex was independent. A similar result was previously reported [
15,
17,
22‐
24,
40]. Although Palomar and Gomez [
12] reported greater resilience in women than in men, Fuentes et al. [
41] reported more resilience in male adolescents using a resilience questionnaire developed by the authors. In another study published in 2013, the authors reported greater resilience in women in different age groups (children, adolescents, adults from 18 to 30 years old and adults from 31 to 59) [
22]. These contradictory results indicate that the effect of sex is spurious and ultimately independent.
The sixth objective was to test the construct validity with respect to psychological well-being (convergent validity) and depression, anxiety and parental stress (divergent validity). Because this study had a transversal design, this construct validity is concurrent validity [
42]. We expected a positive correlation with psychological well-being [
14] and a negative correlation with depression, anxiety and parental stress [
18]. The expectations were fulfilled: resilience, which is a positive personality trait, was more closely related to positive emotions (well-being) than to negative emotions (depression, stress and anxiety), which provides evidence of construct validity for the RESI-M.
The RESI-M total score was independent of social desirability, and only the family support factor had a low correlation. Therefore, it is not necessary to control this variable for bias when the RESI-M is used to assess resilience. The association of social desirability with family support may be related to the aspect of self-deception rather than the aspect of impression management. This type of support is highly valued in Mexico [
39]. This affirmation is formulated as a conjecture that could be tested using another scale to measure social desirability that differentiates these two factors, such as the Balanced Inventory of Desirable Responding [
43].
The first limitation of this study was the use of nonprobabilistic sampling. Therefore, the inferences are limited to the Hospital Infantil de México Federico Gómez National Institute of Health. However, it should be noted that the case rate was large, covering more than 90% of the incidence of cancer cases per year in this hospital. The second limitation was an ex post facto design; thus, the data do not allow causal inferences. The third limitation was that resilience was assessed through a single self-report scale. Consequently, the conclusions are restricted to this measurement instrument.
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