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PubMedDate not supplied

[The testing and validation of the German version of the impact on family scale in families with children with disabilities].

Despite increased interest in the wellbeing of families with children with chronic conditions and disabilities, instruments to assess family impact of health conditions are still lacking in German speaking countries. The Impact on Family Scale has been developed in the Anglo-american literature as a self report instrument to assess the consequences of chronic conditions and disability in childhood and adolescence for the family. The present paper describes the translation and psychometric testing of a German version of the Impact on Family scale (Familien-Belastungs[FaBel]-Questionnaire). The questionnaire contains 33 Likert-scaled items to assess the general negative impact of parents, the description of social relationships, the concern for siblings, the financial impact and problems in coping as well as a total score. The FaBel questionnaire was used and tested for psychometric criteria of reliability and validity in a cross-sectional study of 273 families with children with chronic conditions and disabilities. The results of this psychometric testing of the FaBel-Questionnaire show acceptance by responders, acceptable construct validity, good internal consistency and discriminant validity. The psychometric structure of the questionnaire corresponds with psychometric results with another German population of children with chronic conditions. The results suggest the applicability of the instrument to assess family impact of chronic disease and disability in children and adolescents.

Adolescent↗

PubMed2005

Use of the QOL-AD for measuring quality of life in people with severe dementia--the LASER-AD study.

BACKGROUND: Health-related quality of life (HR-QOL) scales are particularly important in older people as global outcome measures for interventions. It is known that people with mild to moderate dementia can provide valid assessments of their own QOL, but it is unclear whether these instruments are useful in those with severe dementia. OBJECTIVE: We examined the usefulness of the QOL scale in Alzheimer's disease (QOL-AD) in people with severe dementia by considering the ability of older people with a Mini-Mental State Examination (MMSE) score of <12 and their caregivers to complete this scale, as well as its construct validity and internal consistency. METHODS: Data were collected from people with Alzheimer's disease and their caregivers using a range of instruments measuring cognition, mood, behaviour, QOL and functional ability. RESULTS: Of 79 participants and their caregivers, 41 (52%) could complete the QOL-AD. Cognition and functional abilities were significantly higher in the completers than in the non-completers (P < 0.001). The QOL-AD showed internal consistency and construct validity as it correlated with ability to look after self, fewer limitations due to physical health, positive mood status and low levels of apathy. CONCLUSIONS: There is evidence for the validity and reliability of the QOL-AD in people with MMSE scores of 3-11, as well as the practicality of administering the scale in this population. The scale is unlikely to generate useful information for people with MMSE scores of <3. QOL does not decrease as cognition worsens. This throws into question most people's assumption that decreasing cognition worsens QOL. We consider that it may be important to inform the public of this, as living wills are used increasingly in our culture.

Aged↗

PubMedDate not supplied

The psychometric characteristics of the IPR inventory: data from rural Western Australia. Interpersonal Relationships Inventory.

BACKGROUND: Although there is evidence of the psychometric adequacy of the Interpersonal Relationships Inventory (IPRI), the scale was validated on urban North American samples and may function differently in populations that do not share urban United States attitudes toward the giving and receiving of social support. OBJECTIVES: To determine the psychometric characteristics of the IPRI in a sample of rural Australians and compare our findings to previous studies. METHOD: A survey containing the IPRI, the Zung Self-Rating Depression Scale, and a 4-point self-rating measure of physical health was posted to residents of rural communities in Western Australia. The 382 respondents who returned usable surveys had a mean age of 44 years and 71% of them were female. RESULTS: The essential findings of the original IPRI study were replicated. The social support and the conflict subscales were shown to be valid and internally consistent; the reciprocity subscale was internally consistent but its validity was equivocal. Support and conflict proved to be good predictors of severity of depression, and each of the three subscales could reliably discriminate among groups who rated their physical health as poor, fair, good, or excellent. CONCLUSION: The consistent results across the two studies provide further evidence for the psychometric adequacy of the IPRI and suggest that Western societies, urban or rural, interpret and manifest the constructs of support, reciprocity, and conflict in much the same ways.

Adult↗

PubMedDate not supplied

International Study of Asthma and Allergies in Childhood (ISAAC) written questionnaire: validation of the asthma component among Brazilian children.

Written questionnaires have been widely used in epidemiological studies of asthma. However, when translated to another language, they must be validated. The International Study of Asthma and Allergies in Childhood (ISAAC) written questionnaire had been previously validated by a comprehensive study, but this had not been done in Brazil. Our objective was to validate the asthma component of the ISAAC self-applicable written questionnaire following its translation to Portuguese. A group of 10 pediatricians and 10 pediatric allergists graded the questions from 0 to 2, and established a maximum score for each question. The questionnaire was answered by parents or guardians of asthmatic children, aged 6 to 7 years old (n = 26) and of nonasthmatic control children of the same age (n = 26); and by asthmatic (n = 33) and nonasthmatic (n = 33) adolescents, aged 13 to 14 years. Half of these individuals responded to the same questionnaire after 2 to 4 weeks. This second response allowed the evaluation of the reproducibility of the ISAAC questionnaire. The maximum global score possible was 14, and cut-off levels of 5 and 6 were found for the groups of 6 to 7 and 13 to 14 year olds, respectively. There was significant agreement between the adolescents' responses to the questionnaire and those from their parents or guardians (74.3%); however, significant discordance was observed for individual questions including "wheezing with exercise." In both age periods the questionnaire was significantly reproducible (Kappa test) (6 to 7 year olds Kw = 1; 13 to 14 year olds Kw = 0.89). In conclusion, the asthma component of the ISAAC written questionnaire was proven to be reproducible, adequate and able to differentiate between asthmatics and controls. Adolescents answered the questionnaire appropriately, however the results suggest that adolescents' parents or guardians underestimate asthma symptoms which interfere little with the adolescent's daily activities.

Adolescent↗

PubMedDate not supplied

Validity of the Composite International Diagnostic Interview (CIDI) psychosis module in a psychiatric setting.

This study aimed to test the procedural validity of the psychosis module of the Composite International Diagnostic Interview (CIDI) by comparing it with diagnostic checklists completed by experienced clinicians. Seventy-five subjects were interviewed using the interviewer-administered version of the CIDI. Their clinician(s) then completed diagnostic checklists for DSMIV and ICD10 diagnoses of schizophrenia. Agreement was measured at the diagnostic, criterion and subcriterion levels. The validity standard (diagnostic checklist) was shown to be reliable with interrater agreement between the clinicians for the diagnosis of schizophrenia being excellent (kappa = 0.82 for DSMIV and kappa = 0.71 for ICD10). The agreement between the CIDI and the clinician checklists varied with sensitivities for DSMIV subcriteria ranging from 0.18 (negative symptoms) to 0.93 (bizarre delusions) and specificities ranging from 0.38 (catatonia) to 0.95 (disorganised speech). A similar pattern was found for ICD10 subcriteria: sensitivity varied from 0.19 (neologisms) to 0.90 (persistent delusions) and specificity varied from 0.39 (catatonia) to 0.95 (negative symptoms). The poorest levels of agreement were found for symptoms requiring interviewer judgement. The CIDI showed good agreement with clinician checklist diagnoses when the criteria were based on questions asked of the subjects. When the interviewer was required to make judgement of behaviours, the agreement between the CIDI and the clinician checklists was lower, resulting in overall poor agreement between the CIDI and the clinician checklists. Suggestions for improving the validity of the psychosis module of the CIDI are made.

Adult↗

PubMed2003

Validity of hospital discharge International Classification of Diseases (ICD) codes for identifying patients with hyponatremia.

Medical diagnosis can be studied using various sources of information, such as medical and hospital discharge records and laboratory measurements. These sources do not always concur. The objective of the present study was to assess the sensitivity, specificity, and positive and negative predictive values of hospital discharge diagnosis compared with clinical laboratory data for the identification of hyponatremia. Patients with hyponatremia were selected from a hospital information system determined by the International Classification of Diseases, 9th edition (ICD-9). The validity parameters for hyponatremia (ICD code 276.1) were estimated by comparison with accurate serum sodium (Na+) levels. A total of 2632 cases of hyponatremia were identified using laboratory measurements (Na+ < or =135 mmol/L). The sensitivity of ICD coding for hyponatremia was maximally about 30% for patients with very severe hyponatremia (Na+ < or =115 mmol/L). Corresponding specificities were high (>99%). In 87% of the cases with severe hyponatremia (Na+ < or =125 mmol/L), other discharge ICD codes reflecting severe morbidity were found. This study suggests that ICD codes for hyponatremia represent only one third of the patients admitted to the hospital and experiencing hyponatremia. About two thirds of the patients with hyponatremia were classified as hospitalized for other reasons. To assess the validity of case finding of patients with hyponatremia, the use of analytical techniques, such as certain laboratory measurements, is advisable.

Female↗

PubMed2006

The reliability, validity and responsiveness of the International Restless Legs Syndrome Study Group rating scale and subscales in a clinical-trial setting.

PATIENTS AND METHODS: To assess the reliability, validity, and responsiveness of the International Restless Legs Syndrome Study Group's rating scale (the International Restless Legs Scale (IRLS)) (V2.0), using pooled data from two matching, placebo-controlled studies of ropinirole for treating Restless Legs Syndrome (RLS). RESULTS: Pooled patient samples comprised 550 patients in the baseline (validation) sample and 439 patients in the week 12 longitudinal (responsiveness) sample. Factor analysis revealed acceptability of the IRLS total score (accounting for 40% of the variance) and that nine of the 10 IRLS items could also be assigned to two distinct subscales, the symptoms or symptoms impact subscales. The IRLS total score, symptoms and symptoms impact subscales had acceptable construct validity, internal consistency reliability (alpha=0.81, 0.80, and 0.76, respectively), and concurrent validity (r=-0.68, -0.52, -0.70, respectively, with the Restless Legs Syndrome Quality of Life questionnaire (RLSQoL) overall life impact score). IRLS scores differed significantly between different levels of sleep problems and Clinical Global Impression (CGI) of health status (P<0.0001), indicating known groups and clinical validity, respectively. Changes in scores differed significantly among CGI 'global improvement' levels (P<0.0001), providing evidence of responsiveness. CONCLUSIONS: The IRLS total score, symptoms, and symptoms impact subscales are reliable, valid, and responsive in a clinical trial setting.

Adult↗

PubMed2002

The Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM): a review of the ICCVAM test method evaluation process and current international collaborations with the European Centre for the Validation of Alternative Methods (ECVAM).

Over the last decade, national authorities in the USA and Europe have launched initiatives to validate new and improved toxicological test methods. In the USA, the Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) and its supporting National Toxicology Program Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM) were established by the Federal Government to work with test developers and Federal agencies to facilitate the validation, review, and adoption of new scientifically sound test methods, including alternatives that can refine, reduce, and replace animal use. In Europe, the European Centre for the Validation of Alternative Methods (ECVAM) was established to conduct validation studies on alternative test methods. Despite differences in organisational structure and processes, both organisations seek to achieve the adoption and use of alternative test methods. Accordingly, both have adopted similar validation and regulatory acceptance criteria. Collaborations and processes have also evolved to facilitate the international adoption of new test methods recommended by ECVAM and ICCVAM. These collaborations involve the sharing of expertise and data for test-method workshops and independent scientific peer reviews, and the adoption of processes to expedite the consideration of test methods already reviewed by the other organisation. More recently, NICEATM and ECVAM initiated a joint international validation study on in vitro methods for assessing acute systemic toxicity. These collaborations are expected to contribute to accelerated international adoption of harmonised new test methods that will support improved public health and provide for reduced and more-humane use of laboratory animals.

Animal Testing Alternatives↗

PubMed2003

Is the Rivermead Mobility Index a suitable outcome measure in lower limb amputees?--A psychometric validation study.

OBJECTIVE: To examine the internal consistency, validity, responsiveness and test scalability of the Rivermead Mobility Index. DESIGN: Methodological research (consecutive sampling, prospective longitudinal study). PATIENTS: 140 unilateral lower limb amputees (79 above-knee and 61 below-knee). METHODS: The Rivermead Mobility Index was administered to all patients at the beginning (T0) and at the end (T2) of the prosthetic training. In 70 of the patients, the Functional Independence Measure and a timed walking test were also carried out. RESULTS: The Cronbach's alpha of the Rivermead Mobility Index was 0.85 and the item-to-total correlation coefficients rpb ranged from 0.33 to 0.74 (p < 0.0001), for the items considered, at T0; 4 correlations were not calculated due to the extremely low variability of some item responses (mode > or = 98%). The correlation (rs) of Rivermead Mobility Index score with the motor subscale of the Functional Independence Measure was 0.83 at T0 and 0.69 at T2 (p < 0.0001, for both) and that with timed walking test 0.70 (p < 0.0001) at T2. The effect size was 1.35. The scalability coefficients were below the limits of acceptability. CONCLUSION: When applied in lower limb amputees, the Rivermead Mobility Index is an ordinal measure with adequate levels of a series of psychometric properties, which seems more useful for epidemiological studies than for clinical decision-making in single patients. Further steps should be considered to improve its item selection, response format and scaling properties.

Adult↗

PubMed1999

Treatment research at the crossroads: the scientific interface of clinical trials and effectiveness research.

OBJECTIVE: Policy and clinical management decisions depend on data on the health and cost impacts of psychiatric treatments under usual care, i.e., effectiveness. Clinical trials, however, provide information on treatment efficacy under best-practice conditions. An understanding of the design, analysis, and conventions of both efficacy and effectiveness studies can lead to research that better informs clinical and societal questions. METHOD: This paper contrasts the strengths and limitations of clinical trials and effectiveness studies for addressing policy and clinical decisions. These research approaches are assessed in terms of outcomes, treatments, service delivery context, implementation conventions, and validity. RESULTS: Clinical trials and effectiveness research share problems of internal and external validity despite more attention to internal validity in clinical trials (e.g., randomization, blinding, standardized protocols) and to external validity in effectiveness studies (e.g., community-based treatments, representative samples). CONCLUSIONS: To develop research at the interface of clinical trials and effectiveness studies, research goals must be redefined, and methods, such as cost-utility and econometric analyses, must be shared and developed. Development of hybrid designs that combine features of efficacy and effectiveness research will require separation of conventions such as frequency of follow-up, intensity of measurement, and sample size from the central scientific issues of aims and validity.

Clinical Protocols↗

PubMed2006

The International Physical Activity Questionnaire (IPAQ): a study of concurrent and construct validity.

INTRODUCTION: The International Physical Activity Questionnaire (IPAQ) was developed to measure health-related physical activity (PA) in populations. The short version of the IPAQ has been tested extensively and is now used in many international studies. The present study aimed to explore the validity characteristics of the long-version IPAQ. SUBJECTS AND METHODS: Forty-six voluntary healthy male and female subjects (age, mean +/- standard deviation: 40.7 +/- 10.3 years) participated in the study. PA indicators derived from the long, self-administered IPAQ were compared with data from an activity monitor and a PA log book for concurrent validity, and with aerobic fitness, body mass index (BMI) and percentage body fat for construct validity. RESULTS: Strong positive relationships were observed between the activity monitor data and the IPAQ data for total PA (rho = 0.55, P < 0.001) and vigorous PA (rho = 0.71, P < 0.001), but a weaker relationship for moderate PA (rho = 0.21, P = 0.051). Calculated MET-h day(-1) from the PA log book was significantly correlated with MET-h day(-1) from the IPAQ (rho = 0.67, P < 0.001). A weak correlation was observed between IPAQ data for total PA and both aerobic fitness (rho = 0.21, P = 0.051) and BMI (rho = 0.25, P = 0.009). No significant correlation was observed between percentage body fat and IPAQ variables. Bland-Altman analysis suggested that the inability of activity monitors to detect certain types of activities might introduce a source of error in criterion validation studies. CONCLUSIONS: The long, self-administered IPAQ questionnaire has acceptable validity when assessing levels and patterns of PA in healthy adults.

Adipose Tissue↗

PubMed1988

A principal-components analysis of the Narcissistic Personality Inventory and further evidence of its construct validity.

We examined the internal and external validity of the Narcissistic Personality Inventory (NPI). Study 1 explored the internal structure of the NPI responses of 1,018 subjects. Using principal-components analysis, we analyzed the tetrachoric correlations among the NPI item responses and found evidence for a general construct of narcissism as well as seven first-order components, identified as Authority, Exhibitionism, Superiority, Vanity, Exploitativeness, Entitlement, and Self-Sufficiency. Study 2 explored the NPI's construct validity with respect to a variety of indexes derived from observational and self-report data in a sample of 57 subjects. Study 3 investigated the NPI's construct validity with respect to 128 subject's self and ideal self-descriptions, and their congruency, on the Leary Interpersonal Check List. The results from Studies 2 and 3 tend to support the construct validity of the full-scale NPI and its component scales.

Adolescent↗

PubMed2007

ADL assessment of nondisabled Turkish children with the WeeFIM instrument.

OBJECTIVE: To evaluate the WeeFIM instrument's reliability and internal construct validity for the Turkish child population. DESIGN: License was taken from UDSmr to use the WeeFIM instrument. For the reliability and validity studies of the Turkish translation of the WeeFIM instrument, 573 Turkish nondisabled children were included in the study. The reliability of the instrument was assessed by Cronbach's alpha coefficient, intraclass correlation coefficient (ICC), and test-retest reliability. Internal construct validity was assessed by both using Rasch unidimensional measurement model and testing for differential item functioning for age and gender. RESULTS: Cronbach alpha value was 0.99 for motor WeeFIM rating and 0.99 for cognitive WeeFIM rating. ICC was 0.81 for motor WeeFIM rating and 0.92 for cognitive WeeFIM rating. The internal construct validity of the Turkish translation of the WeeFIM instrument was confirmed by excellent fit to the Rasch measurement model. Two subscales were found from the principal component analysis of standardized residual correlation for items. Among the items, bowel management, bladder management, eating, and comprehension showed considerable levels of misfit. CONCLUSIONS: The Turkish translation of the WeeFIM instrument is valid, reliable, and practical for the Turkish child population. Further studies are required to determine the cross-cultural validity of the instrument.

Activities of Daily Living↗

PubMed1999

Screening for somatization and hypochondriasis in primary care and neurological in-patients: a seven-item scale for hypochondriasis and somatization.

The aim of this study was to investigate the internal and external validity of the Whiteley Index as a screening instrument for somatization illness. A 14-item version of the Whiteley Index for hypochondriacal traits was given to 99 of 191 consecutive primary care patients, aged 18-65 years, and to 100 consecutive patients, aged 18-60 years, admitted for the first time to a neurological ward. The primary care sample was, in addition, interviewed by means of the SCAN (Schedules for Clinical Assessment in Neuropsychiatry) psychiatric interview. The GPs and the neurologists were asked to rate various characteristics of the patients that might indicate somatization. The internal validity of the Whiteley Index was tested by means of latent structure analysis. On this basis, a reduced seven-item scale (Whiteley-7 scale) and two subscales (i.e., an Illness Conviction and Illness Worrying scale, each with three items) were constructed. All three had a high internal validity fitting into the very restricted Rasch statistical model (p>0.05) and an acceptable transferability between most of the subpopulations investigated. In the primary care population, the Whiteley-7 and the Illness Conviction scales at cut-point 0/1 showed 1.00 and 0.87 sensitivity and 0.65 and 0.87 specificity, respectively, using as "gold standard" the fulfillment of criteria for at least one ICD-10 somatoform disorder, and 0.71 and 0.63 sensitivity and 0.62 and 0.87 specificity, respectively, as gold standard for the fulfillment of criteria for at least one DSM-IV somatoform disorder, excluding the NOS diagnostic group. The Illness Worrying subscale showed less impressive performance in this respect. The agreement between the Whiteley-7 scale including the two subscales and neurologists' rating and the GPs' rating and the somatization subscale on the SCL-90 was modest or worse. It may be concluded that the Whiteley-7 scale and the Illness Conviction subscale had acceptable psychometric profiles, and both seem to be promising screening tools for not only hypochondriasis but also for somatoform disorders in general.

Adolescent↗

PubMed1999

Real world designs in economic evaluation. Bridging the gap between clinical research and policy-making.

This paper identifies the information that economic evaluation should provide to adequately inform policy-makers. First, policy-makers need cost-effectiveness information that is both internally and externally valid. The latter aspect is often ignored and refers to the relevance of the results of economic trials to the specific decision-making context of the policy-maker. Second, policy-makers, like purchasers of care, may want assessments of the overall budget and health impacts of adopting an intervention in a disease or treatment area. This requires more of an aggregate analysis than the current approaches to economic evaluation (which are typically individual-orientated). There are 3 main conceptual approaches to economic evaluation: the use of randomised controlled trials (RCTs), observational studies and modelling. The RCT can be considered as the gold standard in economic evaluation because of its high internal validity, but results should be interpreted with caution because of its low external validity. There a number of options to enhance external validity; of these, additional modelling and observational data seem to be the most promising. To address issues at the system level, disease modelling or public health modelling is suggested. A 3-step approach, comprising successive assessment of internal validity, external validity (real world relevance) and net impact at the system level, can enhance the informative value of economic analyses. For example, this approach has been used to assess the informative value to decision-makers of an RCT in benign prostatic hyperplasia. The analysis emphasised the feasibility and importance of additional modelling beyond the results from an RCT-based economic analysis and provided important information of relevance for policy-making. Because of the need to increase the real world relevance of pharmacoeconomic analyses, there is potentially a large role for modelling in economic evaluation; however, in order to enhance its credibility, more attention should be paid to validity aspects.

Cost-Benefit Analysis↗

PubMed2005

Assessment of radiofrequency exposure from cellular telephone daily use in an epidemiological study: German Validation study of the international case-control study of cancers of the brain--INTERPHONE-Study.

OBJECTIVE: The objective of the study is to validate self-reported cellular phone use information by comparing it with the cumulative emitted power and duration of calls measured by software-modified cellular phones (SMP). The information was obtained using a questionnaire developed for the international case-control study on the risk of the use of mobile phones in tumours of the brain or salivary gland (INTERPHONE-study). METHOD: The study was conducted in Bielefeld, Germany. Volunteers were asked to use SMPs instead of their own cellular phones for a period of 1 month. The SMP recorded the power emitted by the mobile phone handset during each base station contact. Information on cellular phone use for the same time period from traffic records of the network providers and from face-to-face interviews with the participants 3 months after the SMP use was assessed. Pearson's correlation coefficients and linear regression models were used to analyse the association between information from the interview and from the SMP. RESULTS: In total, 1757 personal mobile phone calls were recorded for 45 persons by SMP and traffic records. The correlation between the self-reported information about the number and the duration of calls with the cumulative power of calls was 0.50 (P<0.01) and 0.48 (P<0.01), respectively. Almost 23% of the variance of the cumulative power was explained by either the number or the cumulative duration of calls. After inclusion of possible confounding factors in the regression model, the variance increased to 26%. Minor confounding factors were "network provider", "contract form", and "cellular phone model". DISCUSSION: The number of calls alone is a sufficient parameter to estimate the cumulative power emitted by the handset of a cellular telephone. The cumulative power emitted by these phones is only associated with number of calls but not with possible confounding factors. Using the mobile phone while driving, mainly in cities, or mainly in rural areas is not associated with the recorded cumulative power in the SMP.

Automation↗

PubMed1994

The Index of Readiness: development and psychometric analysis.

This article describes the development and initial psychometric evaluation of a measure of individual appraisal of readiness to initiate health behavior change. Items were developed from inductively generated data to index dimensions of individual appraisal of readiness. Quantification of Index of Readiness content validity was established through the ratings of 10 experts, following criteria established by Imle and Atwood (1988). The instrument was tested in successive steps with 146 individuals who were participating in an outpatient cardiac rehabilitation program, for reliability and validity, including internal consistency reliability, and three forms of validity assessment (content validity, criterion-related validity, and construct validity). The three subscales of Reevaluation of Lifestyle, Identification of Barriers, and Goal Commitment demonstrated internal consistency. Criterion-related and construct validity were substantiated. With refinement, this measure will provide a basis for nursing interventions designed to enhance individual motivation in relation to specific health behaviors.

Adult↗

PubMed2003

Randomized controlled trials in psychiatry. Part II: their relationship to clinical practice.

OBJECTIVE: To discuss the extent to which the results of randomized controlled trials (RCTs) in psychiatry can be generalized to clinical practice. METHOD: Threats to internal and external validity in psychiatric RCTs are reviewed. RESULTS: Threats to internal validity increase the possibility of bias. Psychiatric RCTs have problems with small samples, arbitrary definitions of caseness, disparate definitions of outcome and high spontaneous recovery rates. Particular issues arise in psychotherapy RCTs. Threats to external validity reduce the extent to which the results of a RCT produce a correct basis for generalization to other circumstances. These include high rates of comorbidity and sub syndromal pathology in normal clinical practice, manual-based treatment protocols and varying definitions of successful treatment. CONCLUSIONS: Randomized controlled trials remain the most robust design to investigate the effectiveness of treatments. They should be applied to important clinical questions; and carried out, as far as possible, with typical patients in the clinical conditions in which the treatment is likely to be used.

Evidence-Based Medicine↗