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A review of the validity of the General Health Questionnaire in adolescent populations.

OBJECTIVE: To comprehensively review the validity of the General Health Questionnaire (GHQ) [1] with adolescents (aged 12-19). Although the GHQ has been extensively used and validated with adults and has been frequently used with adolescents, the validity data for this group are sporadic. METHOD: Systematic review of the English language peer-reviewed literature. RESULTS: Eight studies were identified validating the GHQ with young people of which four included only adolescents and four studies involved young adults and adolescents. Of these eight studies, four used an English language version of the GHQ and four used a translated version. CONCLUSION: The GHQ has demonstrated validity with older adolescents (17 + years) from the UK and Hong Kong (Chinese translation) and with girls aged 15 in the UK, but there are few data for either gender, aged less than 15 years. Studies in Australia and Italy reported a high proportion of misclassified cases while the studies in Spain and Yugoslavia included some older subjects (20 + years). Therefore, the validity of the GHQ for adolescents in populations other than the UK and Hong Kong remains to be demonstrated. IMPLICATIONS: Psychiatrists and other mental health professionals need to be aware of the above limitations when using the GHQ as a screening instrument with adolescents. Further studies are required to: (i) determine the minimum age at which it can be employed, (ii) compare the use of adult versus adolescent criterion interviews, (iii) assemble relevant normative data, and (iv) establish the validity of translated versions.

Adolescent↗

Validation of the inflammatory bowel disease questionnaire IBDQ-D, German version, for patients with ileal pouch anal anastomosis for ulcerative colitis.

BACKGROUND AND AIMS: The inflammatory bowel disease questionnaire (IBDQ) is the standard instrument for assessment of health-related quality of life (HRQOL) in patients with inflammatory bowel diseases. It has not been validated for patients with ileal pouch anal anastomosis (IPAA) and ulcerative colitis (UC). METHODS: To determine acceptance (percentage of completed items), reliability (Cronbach's alpha of the IBDQ-D subscales) and convergent validity (correlations of the IBDQ subscales with the questionnaires used for validation) 61 patients with UC (age 52.7 +/- 13.9 years; 47 % female, 53 % male) and IPAA completed the German (Competence Network IBD) version of the Inflammatory Bowel Disease Questionnaire (IBDQ-D), the Short Form Health Survey (SF-36) the Hospital Anxiety and Depression Scale German Version (HADS-D) and the Giessener Symptom List (GBB 24). Face validity was assessed by a physicians' and patients' panel. All 37 patients underwent endoscopy making it possible to differentiate between patients with and without pouchitis (discriminant validity). RESULTS: With 97.7 % completed items the acceptance was high. Cronbach's alpha value for the subscales ranged from 0.71 to 0.93. Missing items covering extraintestinal manifestations of IBD were criticized by patients. The correlation coefficients with comparable subscales of other instruments ranged between 0.41 and 0.76. Patients with clinical pouchitis scored significantly lower in all subscales than patients without pouchitis (p < 0.001). CONCLUSION: The IBDQ-D has good acceptance, reliability, convergent and discriminant validity, but limited face and construct validity in patients with IPAA and UC.

Adult↗

Validity and reliability study of three tinnitus self-assessment scales: loudness, annoyance and change.

CONCLUSIONS: The three tinnitus self-rating scales described herein can be employed as part of "minimal datasets" to reflect the patient's current tinnitus status. These tests are simple and easy to use and can be completed by the patient alone. The results are easy to interpret and provide a good foundation for an effective doctor-patient dialogue. OBJECTIVE: To investigate the reliability and validity of three tinnitus self-rating scales: a six-point response scale for tinnitus loudness; an eight-point response scale for tinnitus annoyance; and a six-point response scale for tinnitus change. MATERIAL AND METHODS: The data for 273 patients participating in 2 separate studies were assessed in terms of their validity and reliability. We used criterion validity to determine whether the scales had empirical associations with external criteria, in this case an already firmly established tinnitus questionnaire. In addition we examined construct validity, i.e. its subcategories convergent and discriminant validity, in order to find out how related or unrelated items or scales were. We tested the reliability and repeatability of the scales using patients on our waiting list for tinnitus desensitization. RESULTS: The test-retest reliability was 0.72 for tinnitus loudness and 0.62 for tinnitus annoyance. Calculations showed that all three scales correlated positively with validated complex scales and thus we considered convergent validity to be adequate.

Adolescent↗

Introduction to the Monte Carlo project and the approach to the validation of probabilistic models of dietary exposure to selected food chemicals.

The Monte Carlo project was established to allow an international collaborative effort to define conceptual models for food chemical and nutrient exposure, to define and validate the software code to govern these models, to provide new or reconstructed databases for validation studies, and to use the new software code to complete validation modelling. Models were considered valid when they provided exposure estimates (e(a)) that could be shown not to underestimate the true exposure (e(b)), but at the same time are more realistic than the currently used conservative estimates (e(c)). Thus, validation required e(b) </= e(a)<e(c). In the case of pesticides, validation involved the collection of duplicate diets from 500 infants for pesticide analysis. In the case of intense sweeteners, a new consumption dataset was created among prescreened high consumers of intense sweeteners by recording, at brand level, all foods and beverages ingested over 12 days. In the case of nutrients and additives, existing databases were modified to minimize uncertainty over the model parameters. In most instances, it was possible to generate probabilistic models that fulfilled the validation criteria.

Diet↗

Confirmatory factor analysis of the Task and Ego Orientation in Sport Questionnaire with cross-validation.

Although a number of factor analytic studies have been conducted on the factorial validity of the Task and Ego Orientation in Sport Questionnaire (TEOSQ), the results have been equivocal. To further substantiate its evidence of validity, this study cross-validated the measurement model using a rigorous structural equation modeling (SEM) approach. Data collected from a college student sample were first analyzed on a calibration sample (n = 439). Results confirmed the two-factor orthogonal structure representing the underlying task and ego orientations. The results were cross-validated on a validation sample (n = 439) using various SEM-based cross-validation procedures. Collectively, these findings support the construct validity of the TEOSQ as a measure of achievement goal orientation.

Achievement↗

Challenges in validating CFD-derived inhaled aerosol deposition predictions.

Computational fluid dynamic (CFD) techniques have provided unprecedented opportunity for investigating inhaled particle deposition in realistic human airway geometries. Several recent articles describing local aerosol deposition predictions based upon "validated" CFD models have highlighted the challenges in validating local aerosol deposition predictions. These challenges include: (1) defining what is meant by validation; (2) defining appropriate experimental data for validation; and (3) determining when the agreement is not fortuitous. The term validation has numerous meanings, depending on the field and context in which it is used. For example, in computer programming it means the code executes as intended, to the experimentalist it means predicted results agree with matched experimental measurements, and to the risk assessor it implies that predictions using new parameters can be trusted. Based on the current literature it is not clear that a consensus exists for what constitutes a validated CFD model. It is also not clear what types of experimental data are needed or how closely the CFD input values and experimental conditions should be matched (similar or identical airway geometries, entrance airflow, or aerosol profiles) to validate CFD derived predictions. Due to the complexity of CFD computer codes and the multiplicity of deposition mechanisms, it is possible that total aerosol deposition may be accurately predicted and the resulting local particle deposition patterns are incorrect, or vice versa. Specific examples and suggestions for several challenges to experimentalists and modelers are presented.

Aerosols↗

Indexes of food and nutrient intakes as predictors of serum concentrations of nutrients: the problem of inadequate discriminant validity. The Polyp Prevention Trial Study Group.

Nutrient indexes derived from food-frequency questionnaires have generally been regarded as acceptably valid for epidemiologic purposes. Evaluations of these indexes, however, have considered only their convergent validity. We suggest that discriminant validity, or the ability to distinguish among exposures to different nutrients, is also important. Using baseline data from a large clinical trial, we tested the discriminant validity of indexes of intake of vitamin E, alpha-carotene, and beta-carotene. Our results suggest that the vitamin E index possesses neither convergent not discriminant validity, the alpha-carotene index adequate convergent and discriminant validity, and the beta-carotene index adequate convergent but no discriminant validity.

Biomarkers↗

Validity of reported energy expenditure and energy and protein intakes in Swedish adolescent vegans and omnivores.

BACKGROUND: It is difficult to obtain accurate reports of dietary intake; therefore, reported dietary intakes must be validated. Researchers need low-cost methods of estimating energy expenditure to validate reports of energy intake in groups with different lifestyles and eating habits. OBJECTIVE: We sought to validate the reported energy expenditure and energy and protein intakes of Swedish adolescent vegans and omnivores. DESIGN: We compared 16 vegans (7 females and 9 males; mean age: 17.4 +/- 0.8 y) with 16 omnivores matched for sex, age, and height. Energy expenditure as reported in a physical activity interview and energy and protein intakes as reported by diet history were validated by using the doubly labeled water method and by measuring urinary nitrogen excretion. RESULTS: The validity of reported energy expenditure and energy and protein intakes was not significantly different between vegans and omnivores. The physical activity interview had a bias toward underestimating energy expenditure by 1.4 +/- 2.6 MJ/d (95% CI: 2.4, 0.5 MJ/d). The diet-history interview had a bias toward underestimating energy intake by 1.9 +/- 2.7 MJ/d (95% CI: 2.9, 1.0 MJ/d) but showed good agreement with the validation method for nitrogen (protein) intake (underestimate of 0.40 +/- 1.90 g N/d; 95% CI: 1.10, 0.29 g N/d). CONCLUSIONS: The physical activity and diet-history interviews underestimated energy expenditure and energy intake, respectively. Energy intake and expenditure were underestimated to the same extent, and the degree of underestimation was not significantly different between vegans and omnivores. Valid protein intakes were obtained with the diet-history method for both vegans and omnivores.

4-Aminobenzoic Acid↗

Automating candidate gene prioritization with large language models: from naive scoring to literature-grounded validation.

MOTIVATION: Identifying promising therapeutic targets from thousands of genes in transcriptomic studies remains a major bottleneck in biomedical research. While large language models (LLMs) show potential for gene prioritization, they suffer from hallucination and lack systematic validation against expert knowledge. RESULTS: The framework identified 609 sepsis-relevant genes with >94% filtering efficiency, demonstrating strong enrichment for inflammatory pathways including TNF-&#x3b1; signaling, complement activation, and interferon responses. Literature validation yielded 30 ultra-high confidence therapeutic candidates, including both established sepsis genes (IL10, TREM1, S100A9, NLRP3) and novel targets warranting investigation. Benchmark validation against expert-curated databases achieved 71.2% recall, with systematic correlation between computational confidence and evidence quality. The final candidate set balanced discovery (11 novel genes) with validation (19 known genes), maintaining biological coherence throughout the filtering process. This framework demonstrates that rigorous methodology can transform unreliable LLM outputs into systematically validated biological insights. By combining computational efficiency with literature grounding, the approach provides a practical tool for prioritizing experimental validation efforts. The modular design enables adaptation to other diseases through knowledge base substitution, offering a systematic approach to literature-guided biomarker discovery. AVAILABILITY AND IMPLEMENTATION: We developed a two-stage computational framework that combines LLM-based screening with literature validation for systematic gene prioritization. Starting with 10&#xa0;824 genes from the BloodGen3 repertoire, we applied multi-criteria evaluation for sepsis relevance, followed by retrieval-augmented generation using 6346 curated sepsis publications. A novel faithfulness evaluation system verified that LLM predictions aligned with retrieved literature evidence. Source code and implementation details are available at https://github.com/taushifkhan/llm-geneprioritization-framework, vector database at https://doi.org/10.5281/zenodo.15802241, and Interactive demonstration at https://llm-geneprioritization.streamlit.app/.

Humans↗

Measuring lay people's perceptions of the quality of primary health care services in developing countries. Validation of a 20-item scale.

INTRODUCTION: Methodologies that have been developed and validated in accordance with accepted scientific standards are needed to monitor and assess the quality of primary health care in developing countries. OBJECTIVE: To present the results of reliability and validity testing of a new instrument of measurement intended to document the user's opinion on the quality of primary health care services. METHODS: The 20-item scale includes three subscales related to health care delivery personnel and facilities. There were 241 people in one city and two villages in Upper Guinea who responded to the questionnaire. An item analysis preceded the test of psychometric properties of the three subscales and of the total score. Reliability was estimated by analyses of internal consistency and the Cronbach's alpha coefficient. A variety of statistical procedures were used to test factorial validity, trait validity (convergent and discriminant) and nomological validity. RESULTS: The reliability of the subscales ranged from 0.71 to 0.88. The validity analyses supported the initial dimensionality and suggested good construct validity. CONCLUSION: Results confirm the value of the use of the scale developed and highlight the need to take into account the diversity of how quality is perceived by lay people in developing countries. It is suggested that the process of formalization of this type of measurement scale be pursued.

Adult↗

Development and initial validation of a measure of coordination of health care.

OBJECTIVE: To describe the development and initial validation of the self-administered Client Perceptions of Coordination Questionnaire. DESIGN: The instrument was developed between 1996 and 1997 through iterative item generation; within a framework of six domains of coordination, addressed across four sectors of health care provision. SETTING: 1193 individuals with complex and chronic health care needs as judged by their general practitioners (GPs), who were participants in a 2-year randomized controlled trial of a coordinated care intervention in Australia. Other samples were collected in one general practice (98) and from attendees of a chronic pain management course (29). MAIN MEASURES: Face and content validity, completion rates, transferability, internal consistency, and construct validity of the 32-item instrument. RESULTS: Most items achieved excellent completion and comprehension rates. The instrument was transferable to another chronically unwell population. Cronbach's alpha of the entire instrument was 0.92, and for six individual scales scores ranged from 0.31 to 0.86. The six scales based on principal components analysis were acceptability, received care, GP, nominated provider, client comprehension, and client capacity. The first four scales were satisfactory, but the client scales were inadequate with poor internal consistency, and convergent and discriminant validity. People with chronic pain syndromes had significantly worse experiences for almost all items, supporting construct validity. CONCLUSION: This instrument is one of the first to attempt to measure coordination of health care. Its strengths include ease of completion, transferability, and promising psychometric properties and construct validity. Problems capturing data about the patient's contribution to coordination highlight a lack of theoretical development in this area. A valid measure of coordination should be useful in needs assessment, program evaluation, and individual provider/practice audit, and would contribute to research into the experience and measurement of patient-focused care.

Adolescent↗

Cross-cultural validity and reliability testing of a standard psychiatric assessment instrument without a gold standard.

The objective of this study was to assess the cross-culture validity and reliability of a standard psychiatric assessment instrument without the usual "gold standards." Normally criterion validity testing requires comparison with such a standard--usually another instrument or a professional diagnosis. Instead local informants identified persons with and without "agahinda gakabije" (a locally described grief syndrome) who were then asked if they thought they had this syndrome and also interviewed using the depression section of the Hopkins Symptom Checklist (DHSCL). To assess criterion validity, interviews where respondent and informant agreed on the presence or absence of agahinda gakabije were compared with depression diagnosis using the DHSCL. We also assessed construct validity (using factor analysis), internal reliability (Cronbach's alpha), and test-retest reliability using results from a subsequent community-based survey employing the DHSCL. We found a similar relationship between depression and agahinda gakabije as between depression and grief in western countries, which supports criterion validity. Construct validity and internal reliability were good (Cronbach's alpha = 0.87). Test-retest reliability of a DHSCL-based scale was less adequate (0.67). Although not replacing the usual gold standards for testing criterion validity, this approach may prove useful where these standards are unavailable. As this includes much of the developing world, this could result in more accurate mental health assessments among populations for whom this has hitherto not been possible.

Adult↗

Patient rating of wrist pain and disability: a reliable and valid measurement tool.

OBJECTIVE: The goal of this study was to develop a reliable and valid tool for quantifying patient-rated wrist pain and disability. DESIGN: Survey, tool development, reliability, and validity study. SETTING: Upper extremity unit. PARTICIPANTS: One hundred members of the International Wrist Investigators were surveyed by mail to assist in development of the scale. Patients with distal radius (n = 64) or scaphoid (n = 35) fractures were enrolled in a reliability study, and 101 patients with distal radius fractures were enrolled in a validity study. INTERVENTION: Information from the expert survey, biomechanical literature, and patient interviews was used as a basis for item generation and definition of structural limitations for a scale that would be practical in the clinic. Patients with distal radius or scaphoid fractures completed the Patient-Rated Wrist Evaluation (PRWE) on two occasions to determine test-retest reliability. Patients with distal radius fractures (n = 101) completed the PRWE and the SF-36 and were tested with traditional impairment measures at baseline and at two, three, and six months after fracture to determine construct and criterion validity. MAIN OUTCOME MEASURES: Reliability coefficients (ICCs) and validity correlations (Pearson product moment correlations). RESULTS: Patient opinions on pain and on ability to do activities of daily living and work were thought to be the most important dimensions to include in subjective outcome tools. Brevity and simplicity were seen as essential in the clinic environment. A fifteen-item questionnaire (the PRWE) was designed to measure wrist pain and disability. Test-retest reliability was excellent (ICCs > 0.90). Validity assessment demonstrated that the instrument detected significant differences over time (p < 0.01) and was appropriately correlated with alternate forms of assessing parameters of pain and disability. CONCLUSIONS: The PRWE provides a brief, reliable, and valid measure of patient-rated pain and disability.

Activities of Daily Living↗

Quantified pain drawing in subacute low back pain. Validation in a nonselected outpatient industrial sample.

STUDY DESIGN: The criterion and construct validities of pain drawing, quantified by a simple total body area score of pain extent (area raw extent assessment score), were analyzed prospectively on consecutive patients (n = 103), drawn from a predefined blue collar worker population, all sick listed for 6 weeks as a result of low back pain. OBJECTIVES: To evaluate the validity of pain drawing as a screening tool in the secondary prevention of subacute low back pain. SUMMARY OF BACKGROUND DATA: Pain drawings have been used clinically for more than 40 years as a complement to a patient's verbal pain descriptions. The main objectives have been to differentiate functional pain from organic pain and to identify meaningful features in spatial-anatomic pain distribution. The ability of the pain drawing to delineate concurrent psychopathology correctly has been questioned. There is no consensus on which scoring method should be used. METHODS: The area raw extent assessment score was analyzed concurrently against the penalty point system and predictively against return to work and absenteeism over a period of 2 years. Content and construct validity assessed the relative influence of medical, psychologic, and subjective disability as well as psychosocial factors. RESULTS: Criterion validation of the area raw extent assessment score showed significant correlations, both concurrently against the penalty point score (r = 0.86, P < 0.001, with explained variance R2 = 0.75, P < 0.001) and predictively against occupational handicap (r = 0.48, P < 0.001). In construct validation, the highest explained variance was shown for medical (R2 = 0.46, P < 0.001) and psychologic factors (R2 = 0.46, P < 0.001) and psychologic factors (R2 = 0.34, P < 0.001) and for subjective disability (R2 = 0.32, P < 0.001). Variance in the area raw extent assessment score also was explained by psychosocial factors (R2 = 0.19, P < 0.01). CONCLUSIONS: Pain drawing quantification of the extent of pain shows high criterion and construct validity for the area raw extent assessment score. Content validity could be shown for significant clinical aspects of the disability experience--assets preferred for a screening tool in secondary prevention.

Activities of Daily Living↗

Criterion validity of the cervical range of motion (CROM) goniometer for cervical flexion and extension.

STUDY DESIGN: This study used a validity protocol. OBJECTIVE: To estimate the criterion validity of the Cervical Range of Motion goniometer using a healthy population. SUMMARY OF BACKGROUND DATA: The results of the 1994 study by Mayo et al show that there are no validated tools currently available for clinically measuring the cervical range of motion. Numerous decisions regarding patient status and treatment are based wholly or in part on joint motion measurements. Because of current budgetary restrictions, clinicians are being asked to justify their interventions objectively, and to do so, they will need validated tools. METHODS: The population consisted of 31 healthy participants ranging in age from 18 to 45 years. None had experienced cervical problems in the previous 3 months or were pregnant. Data collection took place at the radiology department. After participants were positioned on a stool, the cervical range of motion goniometer frame was set on their head by the physiotherapist. With the participant in this neutral position, the physiotherapist took the first Cervical Range of Motion measurement. The radiograph technologist obtained the radiograph immediately afterward. This procedure was repeated with the participant in fully flexed and fully extended positions. RESULTS: A Pearson's r correlation test was used to evaluate the criterion validity of the Cervical Range of Motion goniometer versus the radiographic method. The two measurements proved to be highly correlated (flexion: r = 0.97, P < 0.001; extension: r = 0.98, P < 0.001). CONCLUSIONS: For this population of healthy participants, the Cervical Range of Motion goniometer was found to be valid for measurements of cervical flexion and extension. Further research is needed on the validity of this instrument for other cervical spine movements.

Adolescent↗

Preclinical validation of fluorescence in situ hybridization assays for clinical practice.

PURPOSE: Validation of fluorescence in situ hybridization assays is required before using them in clinical practice. Yet, there are few published examples that describe the validation process, leading to inconsistent and sometimes inadequate validation practices. The purpose of this article is to describe a broadly applicable preclinical validation process. METHODS: Validation is performed using four consecutive experiments. The Familiarization experiment tests probe performance on metaphase cells to measure analytic sensitivity and specificity for normal blood specimens. The Pilot Study tests a variety of normal and abnormal specimens, using the intended tissue type, to set a preliminary normal cutoff and establish the analytic sensitivity. The Clinical Evaluation experiment tests these parameters in a series of normal and abnormal specimens to simulate clinical practice, establish the normal cutoff and abnormal reference ranges, and finalize the standard operating procedure. The Precision experiment measures the reproducibility of the new assay over 10 consecutive working days. To illustrate documentation and analysis of data with this process, the results for a new assay to detect fusion of IGH and BCL3 associated with t(14;19)(q32;q13.3) in lymphoproliferative disorders are provided in this report. RESULTS: These four experiments determine the analytic sensitivity and specificity, normal values, precision, and reportable reference ranges for validation of the new test. CONCLUSION: This report describes a method for preclinical validation of fluorescence in situ hybridization studies of metaphase cells and interphase nuclei using commercial or home brew probes.

B-Cell Lymphoma 3 Protein↗

Validation of the Chinese version of the satisfaction with the nursing home instrument.

AIM: To assess the psychometric properties of the Chinese version of the Satisfaction with the Nursing Home Instrument. BACKGROUND: Resident's satisfaction has been regarded by the literature as a gold standard for quality of nursing home care. Accurate assessment of resident's satisfaction can provide valuable information for implementation of quality nursing home care. However, there is not a validated Chinese tool to serve the purpose. DESIGN: A cross-sectional descriptive survey design. METHODS: Content validity of the Chinese version of the Satisfaction with the Nursing Home Instrument was assessed by the use of expert panel. Construct validity of the Chinese version of the Satisfaction with the Nursing Home Instrument was determined by assessing the correlation between satisfaction with other theoretically related constructs. Internal consistency and stability of the Chinese version of the Satisfaction with the Nursing Home Instrument were determined by Cronbach's method and two-week test-retest reliability. The six-factor structure of the Chinese version of the Satisfaction with the Nursing Home Instrument was assessed by confirmatory factor analysis. Testing was performed on a cluster sample of 330 residents from 16 nursing homes in Hong Kong. RESULTS: The Chinese version of the Satisfaction with the Nursing Home Instrument demonstrated good content validity by having content validity index of 0.93. High construct validity of the Chinese version of the Satisfaction with the Nursing Home Instrument was supported by its significant correlation with depression (r = -0.42, P = 0.000), health-related quality of life (physical component) (r = 0.16, P = 0.042), health-related quality of life (mental component) (r = 0.41, P = 0.000) and global quality of care (r = 0.49, P = 0.000). The Chinese version of the Satisfaction with the Nursing Home Instrument demonstrated satisfactory internal consistency and good stability by having Cronbach's alpha of 0.79 and intra-class correlation coefficient of 0.94, respectively. The six-factor structure of the Chinese version of the Satisfaction with the Nursing Home Instrument was not fully supported by confirmatory factor analysis. CONCLUSIONS: The Chinese version of the Satisfaction with the Nursing Home Instrument is a useful instrument for assessing satisfaction of cognitively intact Chinese nursing home residents. Findings provided initial evidence on its validity and reliability. Further empirical testing is recommended to explore its factor structure. RELEVANCE TO CLINICAL PRACTICE: The Chinese version of the Satisfaction with the Nursing Home Instrument can provide guidance to enhance delivery of high-quality nursing home care for the Chinese population.

Aged↗

External validity: the neglected dimension in evidence ranking.

Evidence that is both accurate (internally valid) and relevant (externally valid) is needed to decide which treatment is best for a particular patient. Evidence rankings facilitate the marshalling of evidence on clinical decisions in the common context of an overwhelming number of studies, some with conflicting results. Evidence from randomized control trials is typically ranked above evidence from non-experimental studies since rankings are based primarily, if not exclusively, on considerations of internal validity. We propose that evidence rankings should consider equally both internal and external validity. External validity includes how closely the study population, the institution types in the study, the types of physicians in the study, the role of clinician decision-making (e.g. dose adjustment) in the study, and the role of patient preferences in the study resemble those in actual practice. The example of spironolactone use in heart failure illustrates the danger in using evidence that is internally but not externally valid. Ideally, a treatment should only be used when both internally and externally valid evidence indicates that it will be useful for the particular patient.

Case-Control Studies↗