Our initial literature search yielded 3,908 potential studies for inclusion, after removal of 801 duplicates. Preliminary review of titles and abstracts resulted in 410 full articles being screened for inclusion. Agreement was obtained on 25 articles and 1 abstract for inclusion in this review and meta-analysis. Two of the studies that met inclusion criteria were the results of the dataset [21, 22]. For this review, both articles were included in the systematic review, however only one data set was included in the meta-analysis. Complete agreement was obtained between the two reviewers; there was no third reviewer needed.
Systematic Review
Included articles ranged in publication year from 2005 to 2023, with 17 (68%) published in the 5 years previous to this review [21–36]. Study sample size ranged from 30 participants [24, 37] to 1,578 [38] participants with a total of 8,052 in all 24 included studies. Studies were conducted in 16 countries: one each in Australia [39], Iceland [24], Japan [27], Jordan [23], Lebanon [26], China [29], Cyprus [40], Indonesia [36], Netherlands [30], Poland [33], South Korea [32], and Malaysia [34]. Two countries each had two studies completed: Brazil [41, 42] and Turkey [28, 31]. Eight studies were conducted in the United States [21, 22, 25, 35, 37, 43–45], with two studies done exclusively with a Native American population using the same data set [21, 22]. The mean ages of study participants ranged from 47.9 years [23] to 66.0 years [32] of age. Five studies were completed in an exclusively female breast cancer population [23, 34, 36, 37, 41], one study was done exclusively with female study participants, however the specific cancer types were not specified [21]. Chen et al. (2021) included an exclusive female population diagnosed with gynecological cancers. The remaining 19 studies were completed in mixed gender populations [24–28, 30–33, 35, 39, 40, 43–46]. No studies reported a gender other than male and female. Ten included articles reported the religious makeup of their sample [23, 25, 30, 31, 34, 35, 37, 39, 43, 45]. Of those, three included an exclusive or almost exclusive Muslin population [23, 31, 34]. The remaining seven articles included a dominant Christian population, reporting specific breakdown of Christian sects [25, 30, 35, 37, 39, 43, 45]. Bai et al. (2015), Daugherty et al. (2005) and Whitford et al. (2008) reported a small percentage of study participants who identified as Jewish, 7.7%, 3%, and 0.2% respectively. No religions were reported outside of Muslin, Christian, and Jewish. All studies were completed with an outpatient cancer population. See Table 1 for a further breakdown of participant cancer type, gender, and religions of included articles.
Table 1
Summary of full-text articles included in this systematic review
First author (pub. year)
Country [reference]
|
Sample Size
|
Cancer Types
|
Study Design
|
Gender
|
Religion
|
Spirituality Assessment Tool
|
QOL Assessment Tool
|
Correlation
(p-value)
|
Al-Natour (2017)
Jordan [23]
|
150
|
Breast 100%
|
Cross-sectional
|
Female 100%
|
Muslim 88.5%
Christian 11.5%
|
FACIT-SP
|
FACT-G
|
0.67
(<0.001)
|
Asgeidottir (2017)
Iceland [24]
|
30
|
Lung 16.7%
Breast 10%
Gyn 10%
Prostate 10%
Colorectal 6.7%
Head and Neck 6.7%
Other 40%
|
Cross-sectional
|
Male 26.7%
Female 73.3%
|
Not reported
|
EORTC QLQ-SWB
|
EORTC QLQ-C30
|
0.386
(0.035)
|
Bai (2018)
United States [25]
|
102
|
Myeloma 22.5%
Breast 17.6%
Lung 16.7%
Colo/Rectal/Prostate 14.7%
Pancreatic 7.8%
Other 20.5%
|
Secondary Analysis
|
Male 38.2%
Female 61.8%
|
Baptist 41.2 %
Christian 23.5%
Church of God in Christ 6.9%
Catholic 4.9%
Methodist 4.9%
Jehovah's Witness 3.9%
Muslim 2.9%
None 2%
Lutheran 1%
|
FACIT-SP
|
FACT-G
|
0.80
(<0.01)
|
Bai (2016)
United States [45]
|
52
|
% not disclosed
Head and neck
GI
Lung
Gyn
|
Secondary Analysis
|
Male 53.8%
Female 46.3%
|
None 21.2%
Protestant 19.2%
Catholic 50%
Jewish 7.7%
Other 1.9%
|
FACIT-SP
|
FACT-G
|
0.74
(<0.001)
|
Brandao (2021)
Brazil [41]
|
108
|
Breast 100%
|
Cross-sectional
|
Female 100%
|
Not Reported
|
WHOQOL-SRPB
|
EORTC QLQ-C30
|
0.372
(<0.001)
|
Chaar (2018)
Lebanon [26]
|
115
|
Not Reported
|
Cross-sectional
|
Male 33%
Female 67%
|
Not Reported
|
FACIT-SP
|
EORTC QLQ-C30
|
0.271
(0.007)
|
Chen (2021)
China [29]
|
705
|
Ovarian 45.7%
Cervical 29.4%
Endometrial 13.3%
Trophoblastic 5.4%
|
Cross-sectional
|
Female 100%
|
Not Reported
|
EORTC QLQ-SWB
|
EORTC QLQ-C30
|
0.468
(<0.01)
|
Damen (2021)
Netherlands [30]
|
400
|
Not Reported
|
Secondary Analysis
|
Male 52%
Female 48%
|
Protestant or Catholic not church going 41%
Protestant or Catholic church going 19%
Other 40%
|
FACIT-SP
|
FACT-G
|
0.43
(<0.001)
|
Daugherty (2005)
United States [43]
|
162
|
GI 49%
Lung 34%
GYN/Urinary 20%
Head and Neck 2%
Other 18%
|
Cross-sectional
|
Male 55%
Female 45%
|
Catholic 53%
Protestant 35%
Jewish 3%
Other 2%
None 8%
|
FACIT-SP
|
FACT-G
|
0.36
(0.001)
|
Del Giglio (2006)
Brazil [46]
|
72
|
Not Reported
|
Cross-sectional
|
Male 36.1%
Female 63.9%
|
Not Reported
|
FACIT-SP
|
FACT-G
|
Not Reported
(0.025)
|
Frost (2013)
United States [44]
|
1578
|
Lung 100%
|
Secondary Analysis
|
Male 52.1%
Female 47.9%
|
Not Reported
|
FACIT-SP
|
SF-8
|
0.52
(not reported)
|
Harbali (2022)
Turkey [31]
|
406
|
Leukemia 27.8%
Lymphoma 20.4%
Lung 19.2%
Breast 8.4%
Colon 4.9%
Pancreas 4.2%
Other 15.1%
|
Cross-sectional
|
Male 56.9%
Female 43.1%
|
Muslim 100%
|
Spiritual Orientation Scale
|
FACT-G
|
0.193
(<0.01)
|
Hsieh (2020) and
Lee Y (2023)
United States (Native American) [21, 22]
|
73
|
Not Reported
|
Cross-sectional
|
Female 100%
|
Not Reported
|
FACIT-SP
|
FACT-G
|
0.58
(<0.01)
|
Kamijo (2018)
Japan [27]
|
176
|
Breast 38.6%
Gyn 25.0%
Pancreatic/liver/bile 15.3%
Colorectal 9.7%
Gastric 3.4%
Lung 2.8%
Urological 0.6%
Thyroid 0.6%
Other 4.0%
|
Cross-sectional
|
Male 25%
Female 75%
|
Not Reported
|
FACIT-SP
|
FACT-G
|
0.7146
(<0.001)
|
Kyranou (2021)
Cyprus [40]
|
104
|
Not Reported
|
Cross-Sectional
|
Male 43%
Female 57%
|
Not Reported
|
EORTC QLQ-SWB
|
EORTC QLQ-C30
|
0.15
(Not Reported)
|
Leak (2008)
United States [37]
|
30
|
Breast 100%
|
Cross-sectional
|
Female 100%
|
Baptist 50%
Pentecostal 6.7%
Presbyterian 3.3%
Muslin 3.3%
Methodist 6.7%
AME Zion 3.3%
No affiliation 3.3%
Other 23.3%
|
Spiritual Perspective Scale
|
Quality of Life Index
|
0.70
(<0.05)
|
Lee, M (2021)
South Korea [32]
|
132
|
Non-Small Cell Lung 100%
|
Cross-Sectional
|
Male 72%
Female 28%
|
Not Reported
|
FACIT-SP
|
EORTC QLQ-C30
|
0.39
(<0.0001)
|
Majda (2022)
Poland [33]
|
101
|
Not Reported
|
Cross-Sectional
|
Male 45%
Female 55%
|
Not Reported
|
Daily Spiritual Experience Scale
|
EORTC QLQ-C30
|
0.516
(<0.001)
|
Pahlevan Sharif (2021)
Malaysia [34]
|
145
|
Breast 100%
|
Cross-Sectional
|
Female 100%
|
Muslin
|
Beliefs and Values Scale
|
McGIll
|
0.46
(<0.05)
|
Puspita (2023)
Indonesia [36]
|
112
|
Breast 100%
|
Cross-Sectional
|
Female 100%
|
Not Reported
|
FACIT-SP
|
SF-36
|
0.817
(<0.001)
|
Randazzo (2021)
United States [35]
|
606
|
Breast 100%
|
Cross-Sectional
|
Female 100%
|
Christian 73.9%
Unknown 13.7%
None 6.3%
|
FACIT-SP
|
FACT-G
|
0.66
(<0.0001)
|
Whitford (2008)
Australia [39]
|
449
|
Head/Neck 10.7%
Urological 17.8%
Breast 26.3%
Colorectal 10.5%
Lung 13.1%
Lymphoma 13.1%
Gyn 2.9%
Sarcoma 1.1%
Upper GI 4.0%
CNS 0.7%
Melanoma 4.5%
Leukemia 0.7%
Unknown 2.7%
Other 2.2%
|
Secondary analysis
|
Male 51.9%
Female 48.1%
|
Christian 57.2%
Jewish 0.2%
Unknown 15.9%
None 17.2%
|
FACIT-SP
|
FACT-G
|
0.59
(<0.001)
|
Yilmaz (2020)
Turkey [28]
|
150
|
GI 69.3%
Breast/Thyroid 30.7%
|
Cross-sectional
|
Male 38.7%
Female 61.3%
|
Not Reported
|
FACIT-SP
|
FACT-G
|
0.619
(0.001)
|
Spiritual Well-Being
To assess spiritual well-being, the Functional Assessment in Chronic Illness Therapy – Spirituality Well-being (FACIT-SP) was used in the majority (68%) of included studies [21–23, 25–28, 30, 32, 35, 36, 39, 43–46]. For studies that used the FACIT-SP, summary spiritual well-being scores ranged from 25.7 (SD 10.0) [32] to 79.3 (SD 18.46) [44]. The FACIT-SP general spiritual well-being scale scores range from 0 to 92, with 92 signifying higher levels of spiritual well-being. Three of the included articles that used the FACIT-SP for their measurement of spirituality did not report their overall mean spirituality score for their study population, however these studies were included based on their inclusion of a correlation coefficient for the relationship between spirituality and QOL [35, 39, 46].
Three of the included studies used the European Organization for Research and Treatment of Cancer Spirituality Scale (EORTC-SP) [24, 29, 40]. For the included studies that used the EORTC-SP, mean spirituality was 60.4 (SD 28.7) [40] and 72.48 (SD 34.99) [29]. An overall mean for spiritual well-being was not provided for one study, however the items means ranged from 2.63 (SD 0.61) to 3.33 (0.99) on a Likert-type scale from 1 (not at all) to 4 (very much) [24]. The EORTC-SP measures spirituality on a scale from 0 to 100, with 100 signifying a higher level of spirituality. One study used the Spirituality Perspective Scale [37]. The Spirituality Perspective Scale measures general spiritual well-being on a scale of 0 to 6, with 6 being high spiritual well-being. In this study the general spiritual well-being mean was 5.65 (SD 0.55) [37]. The Beliefs and Values Scale, a 10-item questionnaire, was also used once [34], by Pahelvan Sharif (2021) as their measurement of spirituality. The mean spirituality of their sample was not reported. The Daily Spiritual Experience Scale, was used once [33]. It is a 15 question measure utilizing a modified, six-point Liker-typet scale [47]. Cumulative scores range from 16 to 96, with higher number corresponding to higher spirituality [47]. Using the Daily Spiritual Experience Scale, Majda (2022) reported a mean spirituality of 65.22 (SD 21.05). Brandao (2021) used the World Health Organization Quality of Life Spirituality, Religiousness and Personal Beliefs Scale (WHOQOL-SRPB) with a mean spirituality score of 17.76 (SD 1.84) [41]. The WHOQOL-SRPB includes 32 Likert-style questions with a score between 0 and 20 with higher numbers signifying higher levels of spirituality [41]. The Spiritual Orientation Scale is a 7-item Likert-type scale with a range from 0 to 108, with higher values corresponding to higher levels of spirituality [31]. Harbali (2022) found the mean spirituality of their sample using the Spiritual Orientation Scale to be 87.9 (SD 18.5). See Table 2 for complete breakdown of measurements of spirituality.
Table 2
Measurements of Spirituality included in Review
Measure
|
# of items
|
Subscales
|
Validated Languages
|
Validated Disease Population
|
Validated Religious Populations
|
Reliability from original factor analysis
|
EORTC-SP
|
32
|
Relationship with others, Relationship with self, Relationship with something greater, Existential,
Relationship with God if applicable
|
Bengali, Chinese, Croatian, Dutch, English, Finnish, French, German, Greek, Icelandic, Italian, Japanese, Norwegian, Persian, Portuguese, Russian, Spanish, Slovak, Swahili, Swedish, and Vietnamese [67]
|
Cancer [68]
|
Abrahamic Religions [68]
|
0.7 [68]
|
FACIT-SP
|
23
|
Meaning, Peace, and Faith along with general measurement of spirituality
|
Arabic, Bengali, Burmese, Chinese, Croatian, Czech, Danish, Dutch, English, Farsi, French, German, Greek, Hebrew, Hindi, Hungarian, Indonesian, Italian, Japanese, Korean, Lithuanian, Malay, Malayalam, Marathi, Nepali, Norwegian, Polish, Portuguese, Serbian, Sinhalese, Spanish, Slovak, Slovene, Swahili, Swedish, Tamil, Telugu, Thai, Turkish, and Vietnamese [69]
|
Cancer, HIV/AIDS [70]
Diabetes, Heart disease, Thyroid disease, Rheumatoid arthritis, COPD [71]
Cystic fibrosis [72]
Orthopedic disease [73]
Psychiatric disorders [74]
|
Judo-Christian[75, 76]
Buddhism [73]
Islam [77]
|
0.88 [70]
|
Spirituality Perspective Scale
|
10
|
N/A
|
Arabic [78], Chinese [79], English, Italian [80], Korean [81], Persian [82], and Spanish [83]
|
Terminally Ill [84]
Chronic Kidney disease [85]
Pregnancy [86]
|
Abrahamic Religions [84]
|
0.89 [84]
|
Beliefs and Values Scale
|
10
|
N/A
|
Arabic [87] and English
|
Cancer
|
Abrahamic Religions, Hinduism, and Buddhism
|
0.94 [88]
|
Daily Spiritual Experience
|
16
|
N/A
|
Arabic, Czech, Danish, Dutch, English, Flemish, Filipino, French, Greek, Hebrew, Hungarian, Italian, Japanese, Korean, Latvian, Lithuanian, Malay, Malayalam, Nepalese, Persian, Polish, Romanian, Russian, Serbian, Slovenian, Thai, Turkish, Ukrainian, Urdu, and Vietnamese [89]
|
Not specified
|
Judo-Christian [90]
|
0.9 [90]
|
WHOQOL
|
32
|
N/A
|
Arabic, Chinese, Croatian, Czech, Danish, Dari, Dutch, English, French, German, Hindi, Hungarian, Italian, Japanese, Kiswahili, Korean, Lithuanian, Norwegian, Polish, Portuguese, Russian, Serbian, Sinhala, Spanish, Swedish, and Turkish [91]
|
Not specified
|
Not specified
|
0.85 [92]
|
Spiritual Orientation Scale
|
7
|
N/A
|
Turkish [31]
|
Unknown
|
Unknown
|
0.87 [31]
|
Quality of Life
The Functional Assessment of Cancer Treatment – General (FACT-G) was the most commonly used measurement of overall QOL (n = 11, 48%) [21, 23, 25, 27, 28, 31, 35, 39, 43, 45, 46]. The European Organization for Research and Treatment of Cancer Comprehensive Quality of Life (EORTC – QOL- C30) was used in eight studies (32%) [24, 26, 29, 30, 32, 33, 40, 41]. The EORTC-QOL-C30 summary of QOL score ranges from 0 to 100 with 100 signifying a higher QOL. In this review, EORTC-QOL-C30 study summary QOL score ranged from 45.2 (SD 24.0) [40] to 78.86 (SD 18.56) [41]. The Short Form 8 (SF-8) [44] and Short Form 36 (SF-36) were each used in a single study. The SF-8 and SF-36 both have a range from 0 to 100, with 100 signifying higher QOL. For the article included in this review, the mean QOL score on the SF-8 was 80 [44], the QOL mean for the SF-36 [36] was not reported in study results. One study each used the McGill Scale [34], and Quality of Life Index [37]. For the Quality of Life Index, a range of 0 to 30 with 30 signifying higher quality of life, was used in a single study with a mean QOL of 26.6 (SD 2.92) [37].
The FACT-G is a commonly used QOL measurement tool designed specifically for use in the cancer population [48]. It includes 27 Likert-style questions and has subscales of physical, social, emotional, and function well-being. It is an international measure having been validated and translated into 74 languages [49]. Original psychometric testing of the FACT-G had good internal reliability [50]. The EORTC-QLQ-C30 was the second most commonly used measurement tool for QOL in the articles included in this review. The EORTC-QLQ-C30 is another well-established, reliable and valid QOL measure specifically designed for the cancer population [48]. The EORTC-QLQ-C30 has been translated and validated in 117 international languages. In addition to a general subscale of global health/QOL, the EORT-QLQ-C30 includes five functional subscales of physical, role, emotional, cognitive, and social. This QOL measurement tool also includes nine symptom subscales of fatigue, nausea and vomiting, pain, dyspnea, insomnia, appetite loss, constipation, diarrhea, and financial difficulties [51].The SF 8 is a shorten form of the SF 36, both of these measure are highly established measurements of QOL in varying setting of disease and health. Similar to the two QOL measure previously discussed, the SF 8 and SF 36 are international measures that have been validated in over 50 languages in over 25 countries. Both the SF 8 and SF 36 have eight subscales including physical functioning, social functioning, role limitations physical, general medical health, mental health, role limitations emotional, vitality, and bodily pain address the psychological domain, and only 15% (n = 11) address the social domain (remaining 10% (n = 7) address global QOL) [52]. Although less commonly used than the previously discussed measurement tools of QOL, the McGill scale and the Quality of Life Index are both well-established tools to measure QOL. The McGill scale was designed to examine QOL in adults facing a life-limiting illness, specifically adults with cancer or HIV/AIDS. The McGill scale is a 14 item questionnaire with four subscales including physical functioning, existential, social, and psychological [53]. Internal reliability for the McGill scale is 0.94 [53]. In addition to English, the McGill scale has been validated in Arabic [54], Chinese [55], Italian [56], Korean [57], and Spanish [58]. The Quality of Life Index is a valid QOL measure with an internal reliability of 0.96 [59]. The Quality of Life Index is a five item questionnaire includes four subscales of health and function, psychological/spiritual, social and economic, and family [59].
Spirituality and QOL Subscales
Thirteen of the included articles included correlations associated with the measurement subscales of QOL in addition to reporting the overall correlation between spirituality and QOL [23, 26–31, 33, 38–40, 43, 45]. Seven of these studies examined QOL using the FACT-G [23, 27, 28, 31, 39, 43, 45]. Five utilized the EORTC-QLQ-C30 as their QOL measurement [26, 29, 30, 33, 40]. Frost et al. (2013) used the SF-8 as their measurement of QOL. Of the 13 articles that included measurement subscales of QOL in their analysis, eight also included subscales of their spirituality measurement in their correlation analysis [26–30, 39, 40, 45]. Of these eight articles, six examined spirituality through the FACIT-SP [26–28, 30, 39, 45] and two through the EORTC-QLQ-SWB [29, 40].
Meta-Analysis
Correlation of Spiritual Well-Being and Quality of Life
Correlations (r) between QOL and spirituality ranged from 0.817 [36] to 0.15 [40] in the included studies. One study was an abstract only and did not report the correlation, however the p-value was given as 0.025 [46]. All correlations were positive and statistically significant with a p-values of less than 0.05. These positive correlations signify that with higher spirituality, QOL was also higher. It is important to note that these results do not signify a causal relationship due to the limitations of correlations. Kyronou et al. (2021), Harbali et al. (2022), Chaar et al. (2018), Daugherty et al. (2005), Brandao et al. (2021), Asgeirdottir et al. (2017) and Lee et al. (2021) all found a definite, but small, positive correlations based on r’s of 0.15, 0.193, 0.271, 0.36, 0.372, 0.386 and 0.39 respectively [60]. Eleven included articles had a moderate correlation with a substantial relationship with r’s between 0.43 and 0.67 [21, 23, 28–30, 33–35, 39, 44, 60]. The remaining articles included in this review, Leak et al. (2008), Kamijo et al. (2018), Bai et al. (2015 and 2018), and Puspita et al. (2023) had high correlations between spirituality and QOL with values of 0.7, 0.715, 0.74, 0.80, and 0.817 respectfully [60]. The cumulative effect size demonstrated a moderate, substantial relationship between spirituality and QOL in cancer survivors (CES = 0.527; CI 0.463, 0.591; p < 0.001) (Fig. 2) [60].
Correlation of Spiritual Well-Being and Quality of Life Subscales
QOL Subscales
The measurement domains of QOL included a combination of those of the FACT-G and the EORTC-QOL-C30, namely: physical health, social health, functional health, and emotional health. Frost (2013) did not include the domains of function or emotional health in their analysis. A small but definite relationship was found between physical health and spirituality (CES = 0.242; CI 0.191, 0.293; p < 0.001) (Fig. 3) along with social health and spirituality (CES = 0.323; CI 0.259, 0.388; p < 0.001) (Fig. 4). A substantial relationship was found between functional health and spirituality (CES = 0.444; CI 0.306, 0.582; p < 0.001) (Fig. 5) along with emotional health and spirituality (CES = 0.437; CI 0.389, 0.486; p < 0.001) (Fig. 6).
Spirituality Subscales
For this meta-analysis, only the spirituality subscales of the FACIT-SP are reported here due to the EORTC-QLQ-SWB being used in only two articles. As previously mentioned, the FACIT-SP includes three subscales: meaning, peace, and faith. A substantial relationship was found between meaning and overall QOL (CES = 0.599; CI 0.557, 0.642; p < 0.001) and peace and overall QOL (CES = 0.614; CI 0.572, 0.656; p < 0.001). Faith and overall QOL were found to have a small, but significant relationship (CES = 0.279; CI 0.228, 0.329; p < 0.001). Substantial relationships were also found between meaning and emotional well-being (CES = 0.414; CI 0.365, 0.463; p < 0.001) along with peace and emotional well-being (CES = 0.485; CI 0.438, 0.532; p < 0.001). See Table 3 for the cumulative effect sizes for the subscales of spirituality and QOL.
Table 3
Cumulative effect sizes and confidence intervals for spirituality and QOL subscales
|
Physical Well-Being
|
Emotional Well-Being
|
Social Well-Being
|
Meaning
|
0.314 (0.263, 0.365
|
0.414 (0.365, 0.463)
|
0.365 (0.315, 0.414)
|
Peace
|
0.320 (0.269, 0.371)
|
0.485 (0.438, 0.532)
|
0.374 (0.325, 0.424)
|
Faith
|
0.151 (0.099, 0.204)
|
0.219 (0.167, 0.271)
|
0.176 (0.124, 0.229)
|
Note: all results had a p < 0.001 |