DUKE RELIGION INDEX

Abstract

The Duke Religion Index (DUREL) is a brief, five-item psychometric instrument designed to measure three core dimensions of religiousness: organizational religiosity (OR), nonorganizational religiosity (NOR), and intrinsic religiosity (IR). The scale was developed to provide a comprehensive yet brief and non-offensive measure suitable for health outcomes research, drawing heavily on the foundations established by Hoge’s (1972) intrinsic religiosity scale for its final three items. These items were rigorously selected from a study involving 458 medical patients in the Duke Hospital Study based on high intrinsic factor loadings and significant correlations with health outcomes, including social support, functional impairment, and severity of medical illness. Total scores on the DUREL range from 5 (indicating high religiousness) to 27 (indicating low religiousness).

Keywords

Duke Religion Index, DUREL, Organizational Religiosity, Nonorganizational Religiosity, Intrinsic Religiosity, Hoge Scale, Health Outcomes, Psychological Measurement, Religiousness, Spirituality

Authors

Harold G. Koenig, George R. Parkerson, Kenneth G. Meador

Purpose

The primary purpose of the DUREL is to provide researchers and clinicians with a concise, multidimensional instrument for assessing an individual’s level of religiousness. The authors specifically aimed to create a measure that could be administered quickly and without offense in clinical or community settings, addressing the need for a practical tool in health outcome studies where time constraints are common.

The scale is designed to capture distinct behavioral and experiential components of faith, allowing researchers to differentiate between public religious engagement (OR), private spiritual practices (NOR), and the deeply personal internalization of religious beliefs (IR). This differentiation is crucial, as studies have shown that these dimensions relate to physical and mental health outcomes in unique and overlapping ways.

Construct

The DUREL measures three major, yet distinct, dimensions of religiousness, reflecting the complexity of religious involvement:

• Organizational Religiosity (OR): Measured by the first item, this dimension assesses the frequency of participation in public religious activities, such as attending church or other religious meetings.
• Nonorganizational Religiosity (NOR): Measured by the second item, this dimension focuses on private religious practices, including prayer, meditation, or Bible study performed alone.
• Intrinsic Religiosity (IR): Measured by the final three items, this dimension reflects the extent to which religious beliefs are internalized and integrated into one’s fundamental approach to life and daily dealings. These items were adapted from Hoge’s (1972) scale to measure the depth of personal religious commitment.

The scale treats these three dimensions as conceptually linked but empirically separable factors, allowing for nuanced analysis of the relationship between faith and variables such as physical health, mental health, and social support.

Validity

The validity of the DUREL, particularly the Intrinsic Religiosity (IR) subscale, is strongly supported by its correlation with established measures. The three-item IR subscale demonstrated a strong correlation (r = .85) with Hoge’s full 10-item intrinsic religiosity scale, confirming its ability to capture the intended construct efficiently.

Furthermore, the IR subscale showed only moderate correlations with the behavioral components of the DUREL: OR (r = .40) and NOR (r = .42). This pattern suggests that while the three dimensions are related, they represent distinct aspects of religious life. Data correlating OR and NOR with various health measures—such as functional impairment, severity of medical illness, and depression—suggest that organizational and nonorganizational behaviors are independently related to health outcomes, thereby validating the instrument’s tripartite structure. For instance, OR was linked to greater social support and reduced major depression, whereas NOR showed a mixed association with health, primarily linking to increased social support.

Reliability

Reliability data provided by the authors focused primarily on the three-item Intrinsic Religiosity (IR) subscale, which demonstrated acceptable internal consistency for a brief measure. The IR subscale achieved a Cronbach’s alpha of .75 in the initial study population (Koenig, Parkerson, & Meador, 1997).

No specific reliability data (such as test-retest reliability or internal consistency metrics) were reported for the individual one-item measures of Organizational Religiosity (OR) and Nonorganizational Religiosity (NOR) in the foundational publication. However, the consistent findings regarding their unique predictive power in health studies indirectly support their reliable measurement of distinct religious behaviors.

Factor Analysis

The development of the DUREL involved an implicit factor analysis approach, particularly for selecting the Intrinsic Religiosity items. The authors chose three items from Hoge’s 10-item scale based on their high intrinsic factor loading (all three loaded .72 or greater on the intrinsic factor) within the Duke Hospital Study population. This selection process ensured that the adapted subscale maintained strong psychometric properties reflective of the core intrinsic construct, while minimizing the length of the overall instrument.

The instrument’s structure inherently relies on the assumption of three distinct factors (OR, NOR, IR). The subsequent analysis showing moderate intercorrelations between these subscales, coupled with their unique relationships to various physical and mental health markers, provides empirical support for the three-factor structure underlying the DUREL.

Norms and Standardization

While the initial publication did not present comprehensive descriptive statistics for all five items, the scale has been extensively standardized across diverse populations since its introduction. The initial study contributing to the DUREL’s development involved 458 medical patients in the Duke Hospital Study. Furthermore, the two behavioral items (OR and NOR) were administered to over 7,000 individuals aged 18 to 90 across three separate clinical and community studies, indicating robust data collection efforts for normative comparisons. Descriptive statistics, including means and standard deviations, are available through the ongoing research associated with the Duke Hospital Study.

Instrument

Test Type: Self-report questionnaire / Brief Index

Format: Five items with multi-point Likert-style or frequency response options, resulting in a summed score ranging from 5 to 27.

Language Available: Originally English; translated versions are widely available due to its international use in research.

Population Group: Clinical and Community populations

Age Group: Adults (18 to 90 years)

Population Details: Initially validated on 458 medical patients; normative data collected on over 7,000 persons.

Test Methodology: Brief paper-and-pencil or interview administration; requires only a few minutes to complete.

Keywords

DUREL, Duke Religion Index, Intrinsic Religiosity, Organizational Religiosity, Nonorganizational Religiosity, Psychometrics, Health Outcomes, Medical Research, Duke Hospital Study, Religious Behavior

Authors

Author ORCID Identifier: N/A (Not reported in source material)

Affiliation Email addresses: N/A (Not reported in source material)

Correspondence Address: N/A (Contact information typically associated with Duke University Medical Center)

Permissions & Fee and Test Year

The DUREL is generally considered a public domain instrument for research use, developed by Koenig and colleagues. Users should consult the lead author or Duke University Medical Center for specific usage permissions, especially in commercial applications.

Test Year: 1997

Reference’s

• Koenig, H. G., Parkerson, G. R., & Meador, K. G. (1997). Religion index for psychiatric research: A 5-item measure for use in health outcome studies. American Journal of Psychiatry, 154(6), 885.
• Koenig, H. G. (1997). Is religion good for your health? New York: Haworth Press.
• Koenig, H. G., Hays, J. C., George, L. K., & Blazer, D. G. (1997). Modeling the cross-sectional relationships between religion, physical health, social support, and depressive symptoms. American Journal of Geriatric Psychiatry, 5, 131-143.
• Hoge, D. R. (1972). A validated intrinsic religious motivation scale. Journal for the Scientific Study of Religion, 11(4), 369-376.

Items of the DUKE RELIGION INDEX

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

1. How often do you attend church or other religious meetings? (OR)
   1. More than once a week
   2. Once a week
   3. A few times a month
   4. A few times a year
   5. Once a year or less
   6. Never
2. How often do you spend time in private religious activities, such as prayer, meditation, or Bible study? (NOR)

   More than once a day

   Daily

   Two or more times/week

   Once a week

   A few times a month

   Rarely or never

   The following section contains 3 statements about religious belief or experience. Please mark the extent to which each statement is true or not true for you.

3. In my life, I experience the presence of the Divine (i.e., God). (IR)

   Definitely true of me

   Tends to be true

   Unsure

   Tends not to be true

   Definitely not true

4. My religious beliefs are what really lies behind my whole approach to life. (IR)

   Definitely true of me

   Tends to be true

   Unsure

   Tends not to be true

   Definitely not true

5. I try hard to carry my religion over into all other dealings in life. (IR)

   Definitely true of me

   Tends to be true

   Unsure

   Tends not to be true

   Definitely not true

OR: Organizational Religiosity
NOR: Non-organizational Religiosity
IR: Intrinsic Religiosity