Exploratorische und konfirmatorische Faktorenanalyse

This article describes the utility of factor analysis in the context of developing questionnaires for clinical use in rehabilitation. The basic principles of both exploratory factor analysis and confirmatory factor analysis are presented in order to give the necessary knowledge for choosing between both concepts. Exploratory and confirmatory factor analyses complement one another, and there is a place for both in the process of questionnaire development. Finally, the potential use of factor analysis for scaling procedures as well as intercultural validity studies is outlined.

Verteilung von Schmerzparametern bei chronischen Schmerzpatienten im Vergleich zur Allgemeinbevölkerung

OBJECTIVE

The study analyzes pain complaints of chronic pain patients in comparison to representative data from the general population.

METHODS

In a cross-sectional study 493 patients from different health care settings were interviewed about their pain during the previous 12-month and the currently strongest pain. Locations, frequency, intensity and duration of pain, restrictions in daily activities and utilization of therapies were assessed. For comparison data from the German federal health survey 1998 (n=6702) was used.

RESULTS

The patients experienced pain more frequently and more severely than the general population. The largest difference was found in limitations of daily activities. Several qualitative similarities were observed, e.g. for the relative frequency of pain locations. Most patients reported multiple pain locations. The number of reported pain locations increased with intensity and duration of pain. Women reported more frequent and stronger pain than men, utilized more therapies and underwent more often alternative treatments.

CONCLUSIONS

The high prevalence of pain complaints in both samples indicates the importance of early pain prevention, adequate diagnosis and treatment in order to obviate the development and chronification of pain.

[Assessment of motivational changes in tinnitus sufferers. A study of the transtheoretical model]

OBJECTIVES

Cognitive-behavioural treatment of chronic tinnitus needs active cooperation and motivation in patients. The transtheoretical model (TTM) defines the behavioural change using six different stages of change (SoC). In this study, we examined SoC in patients with tinnitus via a new self-rating instrument.

SAMPLE AND METHODS

An item-pool, consisting of 48 questions, was administered to 125 tinnitus sufferers in a cross-sectional study. In addition to data on tinnitus history, the tinnitus strain (THI, German: TB-12), scores of anxiety and depression (HADS-D), and life quality (SF-12) were assessed.

RESULTS

Four SoC could be identified empirically: (1) precontemplation, (2) contemplation/preparation, (3) action/maintenance, and (4) termination. Associations of the SoC with socio-demographic and tinnitus related data, as well as with the instruments applied, conformed with the theory.

CONCLUSIONS

The results confirm the transfer of SoC theory to patients with tinnitus.

[Structural validity of the Short Form 36 (SF-36) in patients with rheumatic diseases]

BACKGROUND

Quality of life is gaining relevance as a criterion of success in therapeutic outcome studies. In order to record quality of life, disease-specific instruments are being used as well as generic instruments. Generic instruments offer the possibility to compare outcome among different indications; however for this it is necessary to prove the differential factorial validity of the instrument's structure.

AIM OF THE STUDY

Using structural equation modeling the SF-36 was administered to a sample of patients with rheumatic diseases. The sensitivity to change of the measure was calculated after six months. Furthermore, age- and sex-specific scale values were calculated and compared with norm data.

METHODS

SF-36 data of 436 patients as well as sex and age from two scientific rehabilitation research projects were pooled for this secondary analysis.

RESULTS

The structure of the questionnaire proves to be acceptable and comparable with international results. The confirmatory analysis supports the best fit for a model with crossloadings assuming correlated main dimensions. Sensitivity to change is low in general. The best effect size is found for the subscale pain. The comparison with norm data shows that patients are impaired particularly within their physical health (regarding the SF subscales) both at the beginning of the treatment and after six months. In all age groups men have better conditions than women.

CONCLUSIONS

The generic SF-36 show sufficient factorial validity. From this point of view there is no objection to using the SF-36 in patients with rheumatic diseases. Indeed the use of the SF summary scales as a representation of (uncorrelated) physical and mental health must be questioned critically.

Ein Fragebogenset zur Erfassung (Screening) psychischer Störungen und sozialer Probleme von Patienten in der kardiologischen Rehabilitation

A set of questionnaires for the assessment (screening) of psychological and social problems in cardiac rehabilitation patients is analyzed for its psychometric properties. The test battery had before been consented by a task force of the German Association for the Prevention and Rehabilitation of Cardiovascular Disease, DGPR. It integrates generally approved and well-tried assessments for depression/anxiety, social isolation (vocational) stress, and subjective vocational disability. The questionnaire was administered to a convenience sample of 426 patients undergoing inpatient cardiac rehabilitation. Results on the psychometric properties, a comparison of the cardiac sample to the general population, as well as distributions of quartile ranges are reported. Also, a preliminary appraisal of the need for further assessment or treatment is made. The results confirm that the short test battery is suited for assessing psychological and social problems in cardiac rehabilitation patients.

[Psychological stress and impaired quality of life in patients with tinnitus]

OBJECTIVES

The majority of patients with chronic decompensated forms of tinnitus have comorbid psychological disorders, possibly accompanied by restricted quality of life and participation in everyday activities. There is no standardized tool to measure these clinically relevant dimensions.

SAMPLE AND METHOD

Both the Hospital Anxiety and Depression Scale (HADS) and the Short Form 36 (SF-36) were administered to a consecutive sample of patients ( n=110) who were recruited from the tinnitus outpatient service in the department of psychiatry and psychotherapy. Using the Tinnitus Questionnaire (TF), associations of the HADS and SF-36 scales with tinnitus grading were determined and the classification of patients (mild-medium-severe-very severe) was evaluated.

RESULTS

A severe tinnitus grading is correlated to a high extent of anxiety and depression and a low quality of life. With the exception of the SF-36 subscale on physical functioning, all scales discriminated between the extreme groups (mild vs severe/very severe), but less between the two medium groups.

CONCLUSIONS

Patients with severe decompensated tinnitus (grades III and IV) should be seen for diagnosis of psychiatric comorbidity and supportive psychotherapy/psychopharmacotherapy used when necessary.

[Relationship of depression and anxiety with social desirability in chronic pain patients]

OBJECTIVE

This study examines the extent of self-reported pain and psychological distress in chronic pain patients and the influence of social desirability on the data collected.

METHODS

In a cross-sectional multi-center study with 494 chronic pain patients, a pain questionnaire was used similar to the German Federal Health Survey of 1998. Depression and anxiety were measured with the German version of the Hospital Anxiety and Depression Scale (HADS-D) and social desirability with the German Marlowe-Crowne short scale for the measurement of social desirability (KS-SE).

RESULTS

Chronic pain patients reported stronger and more frequent pain, as well as higher psychological distress than the general population of Germany. Of the patients, 36.4% showed depression (HADS-D/D >or =9) and 31.4% anxiety (HADS-D/A > or =11). Depressed/anxious patients stated pain intensities higher than non-depressed/non-anxious patients. In all, 48.4% of the patients achieved social desirability levels in the marked or moderate range. There were positive correlations for social desirability with self-reported pain and the use of therapy, as well as age. A negative correlation was found between anxiety and social desirability, while for depression this interaction appeared only after partial correlation analysis with control of pain and therapy variables.

CONCLUSIONS

Both psychological distress and social desirability are common in chronic pain patients. Patients with high scores for social desirability reveal less depression and anxiety. The psychological distress caused by pain seems to be expressed by somatic complaints and therapy seeking. Since pain research is strongly dependent on the patient's self-report, social desirability should be considered as a factor which may impact measurements and decisions.

Erfassung der beruflichen Rollenqualität und ihre prognostische Bedeutung für die Wiederaufnahme der Berufstätigkeit

Non-medical factors such as age, years of schooling, and job satisfaction play an important role in determining whether patients resume their work after rehabilitation treatment. One element is the way the work situation is perceived by the patient. Usually, aspects of strain or job concerns are assessed. But employment does also include positive and rewarding aspects, though, such as meaning or social contact. According to the concept of work-role quality, theoretically these are independent constructs: someone may perceive job concerns and job rewards at the same time. In this study a short questionnaire (FRQ-B), broadly adapted from Barnett, Davidson and Marshall (1991), measuring job concerns and job rewards was developed and administered to a sample of cardiac rehabilitation patients. Psychometric analysis shows the factorial validity, consistency and construct validity of the instrument. Prediction of the return to work status three months after discharge from rehabilitation could be achieved on the item and subscale level. The effect sizes were comparable to other significant variables (e. g. psychological status, NYHA-status, wish to work). Specificities vary from 30 to 60 percent. The best predictor seems to be the Fear Avoidance Belief Questionnaire (FABQ), assuming a causal relationship be-tween work and illness. An analysis of subgroups using the FRQ-B reveals patients who experience little job rewards as well as many job concerns as a group with a high risk of not returning to work. The results of this study demonstrate the importance of assessing work related variables when dealing with return to work after rehabilitation treatment. Interventions to change the perception of the working place situation should be initialized and focussed early in rehabilitation treatment. The need for further research integrating the concept of work-role quality is discussed.

[Measuring the willingness of chronic pain patients to change pain management behavior - a study on the transtheoretical model]

RESEARCH QUESTION

The transtheoretical model (TTM) describes the willingness of behavior change as a process characterized by six stages: precontemplation, contemplation, preparation, action, maintenance, and termination. This study investigates the possibility to apply the TTM to the treatment of chronic pain patients. The main goal is the development of items for a self-administered instrument, which documents the willingness to use cognitive-behavioral methods for pain management independently. With this instrument a treatment can be assigned according to the patient's motivation in order to improve outcomes of pain management programs.

METHODS

Based on TTM theory 56 items were developed and adminstered to a sample of 118 chronic pain patients, who were recruited via different facilities for pain therapy. Item- and factor analysis were conducted for determining psychometrical attributes of items and latent scales.

RESULTS

Analyses resulted in four consistent scales and accordingly four distinctive stages: precontemplation, preparation, action, and maintenance, which showed sufficiently high indices of homogeneity and discriminant validity. The relationships between scale scores and sociodemographic and pain related variables proved to be in accordance to the theory.

CONCLUSIONS

The results show transferability of the TTM to pain management in general. Two stages, contemplation and termination, could not be identified yet. Mainly termination seems not to be existent in the context of pain management. A further study should confirm these findings before therapeutical interventions can be assigned more specifically by the motivational preparedness.

Return to work after myocardial infarction/coronary artery bypass grafting: patients' and physicians' initial viewpoints and outcome 12 months later

Nonmedical factors play an important role in determining whether patients resume their work after myocardial infarction or CABG. The main questions dealt with in this study are: What is the respective basis of physicians' and patients' judgements as far as vocational disabilities are concerned, and what are the decisive factors that facilitate a prediction as to who will return to work and who will not? 132 male patients participating in a cardiac rehabilitation program served as subjects. The age group was limited to patients between 40 and 59 yr of age. The work situation 12 months following rehabilitation is known for 119 subjects; 74 had resumed their occupations. Results of regression analyses show that patients' and physicians' views on disabilities and re-employment are based on different factors. The physicians derive their estimates mainly from medical variables (cardiac status and comorbidity), whereas the patients' views are based on the overall health status, their former job status, job satisfaction, and negative incentives for the return to work. Three variables were found that allow a prediction to be made as to re-employment in 85% of all cases: (1) age, (2) patients' feelings about the extent to which they are disabled by their cardiac problem, and (3) the physicians' views on the extent to which the patient is vocationally disabled by his overall medical situation. Medical variables (e.g. cardiac status) had little relevance to re-employment. The results are discussed with regard to the consequences for cardiac rehabilitation.

[Freiburg/Bad Säckingen Scientific Rehabilitation Research Group]

The Freiburg/Bad Säckingen Rehabilitation Research Network aims on problem solutions in rehabilitation in Germany. The core concept of the Research Group is "goal orientation in diagnosis, therapy and evaluation". This concept refers to both individual goals of patients and structural measures. The 13 projects of the Research Group deal with topics such as "specific communication problems in rehabilitation", "differential indication", "health economics", "methods", and "intervention and evaluation". To establish a long-term internal network in the Research Group and to facilitate intensive communication and co-operation between the various university-based and non-university-based institutions of rehabilitation in the Research Group area, Project Management and Methodological Support Offices were created.