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Results for “External validity”

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At least 289 records · Page 16Linked to original sources

PubMed2002

The Bech-Rafaelsen Melancholia Scale (MES) in clinical trials of therapies in depressive disorders: a 20-year review of its use as outcome measure.

OBJECTIVE: To evaluate the psychometric properties of the Bech-Rafaelsen Melancholia Scale (MES) by reviewing clinical trials in which it has been used as outcome measure. METHOD: The psychometric analysis included internal validity (total scores being a sufficient statistic), interobserver reliability, and external validity (responsiveness in short-term trials and relapse prevention in long-term trials). RESULTS: The results showed that the MES is a unidimensional scale, indicating that the total score is a sufficient statistic. The interobserver reliability of the MES has been found adequate both in unipolar and bipolar depression. External validity including both relapse, response and recurrence indicated that the MES has a high responsiveness and sensitivity. CONCLUSION: The MES has been found a valid and reliable scale for the measurement of changes in depressive states during short-term as well as long-term treatment.

Clinical Trials as Topic↗

PubMed2005

Validation of a decision model for preventive pharmacological strategies in postmenopausal women.

BACKGROUND: Benefits and risks of a combined hormone replacement therapy (HRT) based on randomized clinical trial emerged on various disease endpoints in 2002. The Women's Health Initiative (WHI) provides an important health answer for healthy postmenopausal women, such as do not use combined HRT to prevent chronic disease, because of the elevated risk of coronary artery disease (CHD), stroke and venous thromboembolism. In March 2004, the NIH stopped the drugs in the estrogen-alone trial after finding an increase risk of stroke and no effect, neither an increase or a decrease, on risk of CHD after an average of 7 years in the trial. On the other hand, raloxifene, which does not seem to significantly increase the risk of cardiovascular events and could retain skeletal benefits without stimulating endometrial and breast tissue, requires decision-makers since no current data on these disease clinical endpoints have been published. OBJECTIVE: To construct a multi-disease model based on patient-specific risk factor profiles, and to validate the multi-disease model with several tools of internal and external validities. METHODS: A Markov state model was developed. The risks of these various diseases (including coronary artery disease, stroke, hip fracture and breast cancer) are derived from published hazards proportional models which take into account significant risk factors. Canadian-specific rates and data sources for these transition probabilities are derived from published studies and Canadian Health Statistics. The validation of our model were based on several tools of internal and external validities, such as Canadian life expectancy, population-based incidence rate of diseases, clinical trials and other published life expectancy models. RESULTS: First, presumably, small changes in the lifetime probability of dying support the hypothesis that the disease states operate in a largely independent fashion. For instance, the difference in the probability of dying from a particular disease by the complete elimination of a selected disease, such as CHD, stroke or breast cancer, ranged from 0.2 to 2.2% of difference in the lifetime probability of dying of these diseases. Second, we demonstrated that the model adequately predicted the Canadian population lifetable and disease-incidence rates from population-based data among women from 45 to 75 years old. The predictions of the model were cross-checked from non-source data, such as predicted outcomes versus observed outcomes from results of clinical trials. Predicted relative risks of CHD event, breast cancer and hip fracture fell in the reported 95% confidence interval of clinical trials. Finally, predicted treatment benefits are comparable with those of published life expectancy models. CONCLUSIONS: The results of the study demonstrated that this multi-disease model, including coronary artery disease, stroke, hip fracture and breast cancer, is a valid model to predict the impact on life expectancy or number of events prevented for preventive pharmacological interventions.

Aged↗

PubMed2003

Pretreatment nomogram that predicts 5-year probability of metastasis following three-dimensional conformal radiation therapy for localized prostate cancer.

PURPOSE: There are several nomograms for the patient considering radiation therapy for clinically localized prostate cancer. Because of the questionable clinical implications of prostate-specific antigen (PSA) recurrence, its use as an end point has been criticized in several of these nomograms. The goal of this study was to create and to externally validate a nomogram for predicting the probability that a patient will develop metastasis within 5 years after three-dimensional conformal radiation therapy (CRT). PATIENTS AND METHODS: We conducted a retrospective, nonrandomized analysis of 1,677 patients treated with three-dimensional CRT at Memorial Sloan-Kettering Cancer Center (MSKCC) from 1988 to 2000. Clinical parameters examined were pretreatment PSA level, clinical stage, and biopsy Gleason sum. Patients were followed until their deaths, and the time at which they developed metastasis was noted. A nomogram for predicting the 5-year probability of developing metastasis was constructed from the MSKCC cohort and validated using the Cleveland Clinic series of 1,626 patients. RESULTS: After three-dimensional CRT, 159 patients developed metastasis. At 5 years, 11% of patients experienced metastasis by cumulative incidence analysis (95% CI, 9% to 13%). A nomogram constructed from the data gathered from these men showed an excellent ability to discriminate among patients in an external validation data set, as shown by a concordance index of 0.81. CONCLUSION: A nomogram with reasonable accuracy and discrimination has been constructed and validated using an external data set to predict the probability that a patient will experience metastasis within 5 years after three-dimensional CRT.

Adenocarcinoma↗

PubMed2005

Impact of participant and physician intervention preferences on randomized trials: a systematic review.

CONTEXT: Allocation on the basis of randomization rather than patient choice is the gold standard of unbiased estimates of efficacy in clinical medicine. However, randomly allocating patients to treatments that do not accord with their preferences may influence internal and external validity. OBJECTIVE: To determine whether preferences affect recruitment to trials (external validity) and outcomes in trials (internal validity). DATA SOURCES: We searched MEDLINE, EMBASE, PsycINFO, CINAHL, AMED, and the Cochrane Library for articles published between 1966 and September 2004. We also hand-searched several major medical journals, searched reference lists of relevant articles, and contacted authors of published preference designs. The 2 themes in the first filter of the search strategy were preferences and possible determinants of preferences. STUDY SELECTION: Comprehensive cohorts and 2-stage trials that measured or recorded patient or physician preference, included allocation of participants to random and preference cohorts, and followed up all participants. We excluded trials with no recording of preference; of decision aids; with measurements of preferences for economic analyses; in which patients who refused randomization were followed up without reference to preferences; and of nonclinical populations. DATA EXTRACTION: Up to 4 reviewers independently evaluated the articles, and disagreements were resolved at project steering group meetings. We extracted data on study design, measurement of preference, recruitment, attrition, and summary data on the primary outcome(s) at baseline and each follow-up point. DATA SYNTHESIS: Of 10,023 citations identified, 170 articles met screening criteria and 32 (27 comprehensive cohorts and 5 two-stage trials) were determined to be eligible and were used in the final review. Although treatment preferences led to a substantial proportion of people refusing randomization, there was less evidence of bias in the characteristics of individuals agreeing to be randomized. Differences in outcome across the trials between randomized and preference groups were generally small, particularly in large trials and after accounting for baseline measures of outcome. Therefore, there was little evidence that preferences substantially interfere with the internal validity of randomized trials. CONCLUSIONS: Preferences influence whether people participate in randomized trials, but there is little evidence that they significantly affect validity.

Humans↗

PubMed2003

Measurement of depression in patients with chronic obstructive pulmonary disease (COPD).

OBJECTIVE: To estimate the validity of the Hamilton Depression Scale (HDS) in a population of patients with chronic obstructive pulmonary disease (COPD). METHODS: Forty-nine patients with moderate to severe COPD were examined using the ICD-10 criteria for depression. The mean age of the patients was 71 years and 33 (64%) were women. Forty-six (94%) of the patients were also evaluated using the 17-item HDS including the six-item Hamilton Depression subscale (HDSS). Internal and external validity were measured using factor analysis, Cronbach Coefficient alpha, Loevinger coefficient of homogeneity, correlation analysis and ROC-curves. RESULTS: Twenty-three (47%) of the patients were depressed according to the ICD-10 criteria for depression. The HDSS but not the HDS showed a good internal validity. An acceptable external validity was furthermore shown for the HDSS. CONCLUSION: The HDSS can be recommended as a suitable depression rating scale for COPD patients.

Aged↗

PubMed2002

Identifying patients for blood conservation strategies.

BACKGROUND: Generally, only the type of operation is used to estimate the need for perioperative homologous blood transfusion. This study quantified the extent to which the estimation could be improved if, in addition, simple patient characteristics were taken into account. METHODS: Retrospective data on 24 509 consecutive adult surgical patients were used to derive and validate three models to predict perioperative homologous transfusion. The first model was a univariable model with type of operation as the only predictor. The second and third models were a full and a simplified multivariable logistic regression model. The performance of the multivariable models was tested in two validation sets: in similar patients who had operations in the same general hospital (internal validation) and in patients who had operations in a university hospital (external validation). The areas under the receiver-operator characteristic (ROC) curve were compared with that found in the derivation set. RESULTS: There were no important differences in characteristics between the derivation and validation sets. The ROC area of the model including surgery only was 0.92 (99 per cent confidence interval (c.i.) 0.91 to 0.94) and that of the full and simplified multivariable models 0.95 (99 per cent c.i. 0.94 to 0.96) and 0.94 (99 per cent c.i. 0.93 to 0.95) respectively. The latter two were significantly different from the first one. In the external validation set the ROC area of the simplified model was 0.84 (95 per cent c.i. 0.83 to 0.86). Patients who had a preoperative haemoglobin level lower than 13 g/dl and underwent major invasive surgery had the highest risk (43 per cent) of transfusion. CONCLUSION: A simple algorithm using type of operation and haemoglobin concentration was effective in identifying patients likely to need perioperative homologous blood transfusion.

Adult↗

PubMed2006

Risk equation determining unsuccessful cannulation events and failure to maturation in arteriovenous fistulas (REDUCE FTM I).

Fistulas are the preferred permanent hemodialysis vascular access but a significant obstacle to increasing their prevalence is the fistula's high "failure to mature" (FTM) rate. This study aimed to (1) identify preoperative clinical characteristics that are predictive of fistula FTM and (2) use these predictive factors to develop and validate a scoring system to stratify the patient's risk for FTM. From a derivation set of 422 patients who had a first fistula created, a prediction rule was created using multivariate stepwise logistic regression. The model was internally validated using split-half cross-validation and bootstrapping techniques. A simple scoring system was derived and externally validated on 445 different, prospective patients who received a new fistula at five large North American dialysis centers. The clinical predictors that were associated with FTM were aged > or =65 yr (odds ratio [OR] 2.23; 95% confidence interval [CI] 1.25 to 3.96), peripheral vascular disease (OR 2.97; 95% CI 1.34 to 6.57), coronary artery disease (OR 2.83; 95% CI 1.60 to 5.00), and white race (OR 0.43; 95% CI 0.24 to 0.75). The resulting scoring system, which was externally validated in 445 patients, had four risk categories for fistula FTM: low (24%), moderate (34%), high (50%), and very high (69%; trend P < 0.0001). A preoperative, clinical prediction rule to determine fistulas that are likely to fail maturation was created and rigorously validated. It was found to be simple and easily reproducible and applied to predictive risk categories. These categories predicted risk of FTM to be 24, 34, 50, and 69% and are dependent on age, coronary artery disease, peripheral vascular disease, and race. The clinical utility of these risk categories in increasing rates of permanent accesses requires further clinical evaluation.

Adolescent↗

PubMed2002

Assessing socioeconomic status in adolescents: the validity of a home affluence scale.

STUDY OBJECTIVE: To examine the completion rate, internal reliability, and external validity of a home affluence scale based on adolescents' reports of material circumstances in the home as a measure of family socioeconomic status. DESIGN: Cross sectional survey. SETTING: Data were collected from a school based study in seven schools in the north of England Cheshire over a five month period from September 1999 to January 2000. PARTICIPANTS: 1824 students (1248 girls, 567 boys) aged 13-15 years who were attending normal classes in Years 9 and 10 in 7 schools on the days of data collection. MAIN RESULTS: Comparatively poor completion rates were found for questions on parental education and occupation while material deprivation items had much higher completion rates. There was evidence that students with poorer material circumstances were less able to report parental education and occupation whereas material based questions showed less bias. A home affluence scale composed of material items was found to have adequate internal reliability and good external validity. CONCLUSIONS: A home affluence scale based on material markers provides a useful alternative in assessing family affluence in adolescents. Additionally, it prevents exclusion of those less materially well off adolescents who fail to complete conventional socioeconomic status items.

Adolescent↗

PubMed1999

Evaluation and application of models for the prediction of ready biodegradability in the MITI-I test.

Three existing models and one newly developed model for the prediction of ready biodegradability of organic compounds are evaluated by comparing the descriptors they use, and the consistency of the models when applied to the set of High Production Volume Chemicals (HPVC) in the European Union. Linear regression models developed for the OECD showed the best performance in the external validation (84.7% correct), although comparison with the other three models is flawed because of the class specificity of these models. With these models 567 of the 894 compounds could be predicted in the validation. The multivariate statistical model showed the best performance in the external validation (82.7% correct) combined with the broadest applicability of the model. The evaluation of the predictions of the models for the HPVC shows that all models are highly consistent in their prediction of not-ready biodegradability, but much less consistency is seen in the prediction of ready biodegradability. This complies with the observation that all 4 models show better performance in their predictions of not-ready biodegradability.

Analysis of Variance↗

PubMed2002

Validation of a tool to safely triage selected patients with chest pain to unmonitored beds.

OBJECTIVE: To externally validate a chest pain protocol that triages low risk patients with chest pain to an unmonitored bed. METHODS: Retrospective study of all patients admitted from the emergency department of a tertiary referral public teaching hospital with an admission diagnosis of 'unstable angina' or suspected ischemic chest pain. Data was collected on adverse outcomes and analysed on the basis of intention-to-treat according to the chest pain protocol. RESULTS: There were no life-threatening arrhythmias, cardiac arrests or deaths within the first 72 h of admission in the group assigned to an unmonitored bed by the chest pain protocol ([0/244]; 0.0%: 95% confidence interval 0.0-1.5%). Four patients had an uncomplicated myocardial infarction, two patients had recurrent ischemic chest pain and one patient developed acute pulmonary oedema ([7/244]; 2.9%: 95% confidence interval 1.2-5.8%). CONCLUSION: This retrospective study externally validated the chest pain protocol. Care in a monitored bed would not have altered outcomes for patients triaged to an unmonitored bed by the chest pain protocol. Compared to current guidelines, application of the chest pain protocol could increase the availability of monitored beds.

Aged↗

PubMed2006

Clinical prognostic rules for severe acute respiratory syndrome in low- and high-resource settings.

BACKGROUND: An accurate prognostic model for patients with severe acute respiratory syndrome (SARS) could provide a practical clinical decision aid. We developed and validated prognostic rules for both high- and low-resource settings based on data available at the time of admission. METHODS: We analyzed data on all 1755 and 291 patients with SARS in Hong Kong (derivation cohort) and Toronto (validation cohort), respectively, using a multivariable logistic scoring method with internal and external validation. Scores were assigned on the basis of patient history in a basic model, and a full model additionally incorporated radiological and laboratory results. The main outcome measure was death. RESULTS: Predictors for mortality in the basic model included older age, male sex, and the presence of comorbid conditions. Additional predictors in the full model included haziness or infiltrates on chest radiography, less than 95% oxygen saturation on room air, high lactate dehydrogenase level, and high neutrophil and low platelet counts. The basic model had an area under the receiver operating characteristic (ROC) curve of 0.860 in the derivation cohort, which was maintained on external validation with an area under the ROC curve of 0.882. The full model improved discrimination with areas under the ROC curve of 0.877 and 0.892 in the derivation and validation cohorts, respectively. CONCLUSION: The model performs well and could be useful in assessing prognosis for patients who are infected with re-emergent SARS.

Adult↗

PubMed2005

The clinical and cost-effectiveness of implantable cardioverter defibrillators: a systematic review.

OBJECTIVES: To consider the clinical effectiveness and cost-effectiveness of implantable cardioverter defibrillators (ICDs) for arrhythmias. DATA SOURCES: Electronic databases. Manufacturer submissions. REVIEW METHODS: A systematic review of the literature on clinical and cost-effectiveness was undertaken. The quality of selected randomised controlled trials (RCTs) was assessed using the Jadad criteria, and of selected systematic reviews using criteria developed by the NHS Centre for Reviews and Dissemination. Economic evaluations were quality assessed by their internal validity (i.e. the methods used) using a series of relevant questions, and external validity (i.e. generalisability of the economic study to the population of interest) by modified standard criteria. The clinical effectiveness and cost-effectiveness of ICDs for arrhythmias were synthesised through a narrative review with full tabulation of results of all included studies. RESULTS: Eight RCTs, two systematic reviews and a meta-analysis met the inclusion criteria of the review. The RCTs were of variable quality, with most trials having a Jadad quality score of 1/5 or 2/5, owing to the nature of comparing a device with drug therapy and the impossibility of double-blinding. The outcome measure of interest was mortality, which was reported as all-cause mortality in most trials and sudden cardiac death in some trials. Eleven economic evaluations of ICDs for arrhythmias were identified. None were shown to have high internal and external validity. One unpublished study relevant to the UK was identified. The evidence suggests that ICDs reduce mortality in patients with previous ventricular arrest or symptomatic sustained ventricular arrhythmias, in patients who have not had a previous sudden cardiac episode or previous ventricular arrhythmia but have reduced left ventricular function due to coronary artery disease with asymptomatic non-sustained ventricular arrhythmia and sustained tachycardia that could be induced electrophysiologically, and in some patients with severe left ventricular dysfunction (ejection fraction 30%) after myocardial infarction. QoL data are inconsistent but suggest that there is impaired QoL in patients who received numerous shocks from implanted devices. Studies show that ICDs improve survival compared with drug treatment, but with considerably increased cost. Incremental cost per life-year gained ranges from 27,000 US dollars to 213,543 Can dollars and incremental cost per quality-adjusted life-year from 71,700 US dollars to 558,000 US dollars in the published literature. CONCLUSIONS: The use of ICDs in the UK is increasing, but the technology is still under-utilised compared with other developed countries. Extending the current indications to patients with prior myocardial infarction and depressed heart function would impact on costs and service provision. Further research is needed on the risk stratification of patients in whom ICDs are most likely to be clinically and cost-effective. An evaluation of shock frequency on QoL is also required.

Aged↗

PubMed1996

Randomized and non-randomized patients in clinical trials: experiences with comprehensive cohort studies.

In clinical research, randomized trials are widely accepted as the definitive method of evaluating the efficacy of therapies. Random assignment of patients to treatment ensures internal validity of the comparison of new treatments with controls. An assessment of external validity can best be achieved by comparing the randomized study sample to the population of patients who met the eligibility criteria but did not consent to randomization. The Comprehensive Cohort Study (CCS) is designed to recruit all patients fulfilling the clinical eligibility criteria regardless of their consent to randomization. The CCS concept was adopted in the major clinical trials of the German Breast Cancer Study Group (GBSG) conducted between 1983 and 1989. In this period 124 centres recruited 2084 patients in three clinical trials. 734 (35 per cent) of these patients accepted being randomized, while 1350 (65 per cent) chose one of the treatments under study; the randomization rates differed remarkably between trials. In this paper we examine the representativeness of the randomized patients in the three trials. Based on a median follow-up of about 5 years we present results on the external validity of the treatment effects estimated in the randomized patients by means of Cox's proportional hazards model and compare them between trials. We discuss advantages and disadvantages of the CCS design and conclude that its use is only justified under extraordinary circumstances.

Breast Neoplasms↗

PubMed2000

Pros and cons of permutation tests in clinical trials.

Hypothesis testing, in which the null hypothesis specifies no difference between treatment groups, is an important tool in the assessment of new medical interventions. For randomized clinical trials, permutation tests that reflect the actual randomization are design-based analyses for such hypotheses. This means that only such design-based permutation tests can ensure internal validity, without which external validity is irrelevant. However, because of the conservatism of permutation tests, the virtues of permutation tests continue to be debated in the literature, and conclusions are generally of the type that permutation tests should always be used or permutation tests should never be used. A better conclusion might be that there are situations in which permutation tests should be used, and other situations in which permutation tests should not be used. This approach opens the door to broader agreement, but begs the obvious question of when to use permutation tests. We consider this issue from a variety of perspectives, and conclude that permutation tests are ideal to study efficacy in a randomized clinical trial which compares, in a heterogeneous patient population, two or more treatments, each of which may be most effective in some patients, when the primary analysis does not adjust for covariates. We propose the p-value interval as a novel measure of the conservatism of a permutation test that can be defined independently of the significance level. This p-value interval can be used to ensure that the permutation test have both good global power and an acceptable degree of conservatism.

Humans↗

PubMed2005

Application of two chemometric methods for the determination of imipramine, amitriptyline and perphenazine in content uniformity and drug dissolution studies.

Double-divisor spectra derivative and partial least squares methods were developed for content uniformity and dissolution tests in binary or ternary mixtures. The simultaneous determinations of perphenazine (PER) combined with amitriptyline hydrochloride (AMI) and/or imipramine hydrochloride (IMI) have been accomplished using the information of the absorption spectra of appropriate solutions. The double-divisor method is based on the use of the first derivative of the ratio spectrum obtained by dividing the absorption spectrum of the ternary mixture PER-AMI-IMI by a standard spectrum resulted from the addition of two of the three analytes in equal concentrations. The concentration of each component is then determined from their respective calibration graphs established by measuring the ratio derivative analytical signal at a specific wavelength. In this method, the linear determination ranges were of 3.65-18.24 microg/mL for PER, 4.32-21.60 microg/mL for AMI, and 4.83-24.19 microg/mL for IMI. The results were compared with those obtained by partial least squares multivariate calibration (PLS) method pre-treated by a wavelet compression-orthogonal signal correction (W-OSC) filter in zero-order derivative spectra. The calibration model was evaluated by internal validation (cross-validation) and by external validation over synthetic mixtures, content uniformity and dissolution tests. According to the dissolution profile test more than 95% of the three substances were dissolved within 10 min. The results from both techniques were statistically compared with each other and can be satisfactorily used for quantitative analysis and dissolution tests of multicomponent tablets.

Amitriptyline↗

PubMed1998

Factor structure and clinical validity of competing models of positive symptoms in schizophrenia.

BACKGROUND: The factor structure of four competing models of positive symptoms and their clinical validity was studied in a sample of 253 schizophrenia inpatients. METHODS: The following models were tested using confirmatory factor analysis: a one-dimension severity model, a two-dimension model comprising a psychosis factor and a disorganization factor, a four-dimension model based on the Scale for the Assessment of Positive Symptoms (SAPS) structure in subscales, and a five-dimension model derived from the previous one by further differentiating Schneiderian delusions from non-Schneiderian ones. RESULTS: More complex multifactorial models fit the data better than simpler models. The five-dimension model was the best adjusted (goodness of fit index = .844, nonnormed fit index = .812, normed fit index = .728). Whereas the one-dimension model did not display significant association with the clinical variables, multidimensional models were related to age at onset and illness severity. The two-dimension model captured well the clinical correlates of the more complex models. CONCLUSION: None of the tested models showed good fit to the data. The one-dimension model displayed both poor factor validity and poor external validity; therefore, research relying on the SAPS total score may reach misleading conclusions.

Adult↗

PubMedDate not supplied

The future of pharmacoeconomics: bridging science and practice.

In the context of new challenges, issues facing the science, practice, and future of pharmacoeconomics will be discussed. Certain methodologic weaknesses have been observed in published pharmacoeconomic studies, and compromises need to be made between developing an "ideal" method and allowing a study to remain practicable. The objective is to reach a balance between clinical trial-based studies and projective models; trials have high internal validity but low external validity, while models can help explore relevance to real-life settings. Cross-national differences also have an important impact on pharmacoeconomic data; however, using some basic standardized guidelines results from pharmacoeconomic studies may be generalized to other settings. The use of pharmacoeconomic results by decision makers in the United Kingdom has been restrained by unclear priorities within their authority and by the limited availability of credible studies. The future of pharmacoeconomics lies in developing both trial-based and modeling studies, improving their credibility, and meeting the needs of decision makers.

Clinical Trials as Topic↗

PubMed2003

Developing a measure of attitudes: the holistic complementary and alternative medicine questionnaire.

We have developed an 11-item scale, the Holistic Complementary and Alternative Medicine Questionnaire (HCAMQ). Six of the HCAMQ items relate to beliefs about the scientific validity of complementary and alternative medicine (CAM), and five to beliefs about holistic health (HH). The HCAMQ was completed by 50 patients attending a CAM clinic and 50 attending rheumatology outpatients; the former completed it twice. Factor analysis (oblique rotation) showed that the CAM and HH items measured distinct but related constructs. The HCAMQ has good test retest reliability (r=0.86, 0.82 and 0.77 for the total, CAM subscale and HH subscale, respectively). The individuals attending CAM clinics were significantly more positive on the CAM but not the HH subscale of the HCAMQ and also used less antibiotics than those attending rheumatology outpatients. Positivity towards CAM on the total HCAMQ and subscales was significantly associated with lower age, increased vitamin use, reduced painkiller use, and, other than on the HH subscale, less antibiotic use. The reason why the HH subscale failed to distinguish between the two patient groups or predict less antibiotic use is unknown. The HCAMQ appears to have good internal validity, but its external validity remains to be established.

Age Factors↗