Showing papers by "Joop J. Hox published in 2007"

Theory of mind in schizophrenia: meta-analysis.

Abstract: Background Mentalising impairment (an impaired ability to think about people in terms of their mental states) has frequently been associated with schizophrenia. Aims To assess the magnitude of the deficit and analyse associated factors. Method Twenty-nine studies of mentalising in schizophrenia (combined n =1518), published between January 1993 and May 2006, were included to estimate overall effect size. Study descriptors predicted to influence effect size were analysed using weighted regression-analysis techniques. Separate analyses were performed for symptom subgroups and task types. Results The estimated overall effect size was large and statistically significant ( d =–1.255, P <0.0001) and was not significantly affected by sample characteristics. All symptom subgroups showed significant mentalising impairment, but participants with symptoms of disorganisation were significantly more impaired than the other subgroups ( P <0.01). Conclusions This meta-analysis showed significant and stable mentalising impairment in schizophrenia. The finding that patients in remission are also impaired favours the notion that mentalising impairment represents a possible trait marker of schizophrenia.

Take Care! The Evaluation of a Team-Based Burnout Intervention Program for Oncology Care Providers

Abstract: In this quasi-experimental study among staff of 29 oncology wards, the authors evaluated the effects of a team-based burnout intervention program combining a staff support group with a participatory action research approach. Nine wards were randomly selected to participate in the program. Before the program started (Time 1), directly after the program ended (Time 2), and 6 months later (Time 3), study participants filled out a questionnaire on their work situation and well-being. Results of multilevel analyses showed that staff in the experimental wards experienced significantly less emotional exhaustion at both Time 2 and Time 3 and less depersonalization at Time 2, compared with the control wards. Moreover, changes in burnout levels were significantly related to changes in the perception of job characteristics over time.

Deployment-related stress and trauma in Dutch soldiers returning from Iraq. Prospective study.

Abstract: Background Some questionnaire studies have shown increased mental health problems, including probable post-traumatic stress disorder (PTSD), in soldiers deployed to Iraq. Aims To test prospectively whether such problems change over time and whether questionnaires provide accurate estimates of deployment-related PTSD compared with a clinical interview. Methods Dutch infantry troops from three cohorts completed questionnaires before deployment to Iraq ( n =479), and about 5 months ( n =382, 80%) and 15 months ( n =331, 69%) thereafter. Post-traumatic stress disorder was evaluated by questionnaire and clinical interview. Results There were no group changes for general distress symptoms. The rates of PTSD for each cohort were 21, 4 and 6% based on questionnaires at 5 months. The deployment-related rates of PTSD based on the clinical interview were 4, 3 and 3%. Conclusions There was a specific effect of deployment on mental health for a small minority. Questionnaires eliciting stress symptoms gave substantial overestimations of the rate of PTSD.

The Influence of Advance Letters on Response in Telephone Surveys A Meta-Analysis

Abstract: Recently, the leading position of telephone surveys as the major mode of data collection has been challenged. Telephone surveys suffer from a growing nonresponse, partly due to the general nonresponse trend for all surveys and partly due to changes in society and technol- ogy influencing contactability and willingness to answer. One way to counteract the increasing nonresponse is the use of an advance letter. In mail and face-to-face surveys, advance letters have been proven effec- tive. Based on the proven effectiveness in face-to-face and mail surveys, survey handbooks advise the use of advance letters in telephone surveys. This study reviews the evidence for this advice and presents a quantita- tive summary of empirical studies on the effectiveness of advance letters in raising the response rate for telephone surveys. The major conclusion is that advance letters are also an effective tool in telephone surveys, with an average increase in response rate (RR1) from 58 percent (no letter) to 66 percent (advance letter), and an average increase in cooper- ation rate (COOP1) from 64 percent (no letter) to 75 percent (advance letter). Telephone surveys have become more and more popular in the last 30 years, reaching their zenith in the 1990s. At the end of the twentieth century, telephone interviews were the major mode of data collection for surveys of households, individuals, and establishments in North America, Canada, Australia, and parts

The Health-Related Quality of Life of Obese Persons Seeking or Not Seeking Surgical or Non-surgical Treatment: a Meta-analysis

Abstract: Background: This meta-analysis examined differences in health-related quality of life (HRQoL) between seekers of surgical and non-surgical treatment, and non-treatment seekers, over and above differences that are explained by weight, age, and gender. Methods: Our literature search focused on the ‘Impact of Weight on Quality of Life-Lite’ (IWQOL-Lite) and the 'Short Form-36' (SF-36) questionnaires. Included were studies published between 1980 and April 2006 providing pre-treatment descriptive statistics of adult overweight, obese or morbidly obese persons. Excluded were elderly and ill patient groups. Results: 54 articles, with a total number of nearly 100,000 participants, met the inclusion criteria. Persons seeking surgical treatment demonstrated the most severely reduced HRQoL. IWQOL-Lite scores showed larger differences between populations than SF-36 scores. After adjustment for weight, the population differences on the IWQOL disappeared. In contrast, the differences on the SF-36 between the surgical treatment seeking population and the other populations were maintained after adjustment for weight. Conclusion: The IWQOL-Lite questionnaire predominantly reflects weight-related HRQoL, whereas the SF-36 mostly reflects generic HRQoL that is determined by both weight and other factors. Our metaanalysis provides reference values that are useful when explaining or evaluating obesity-specific (IWQOL-Lite) or generic (SF-36) HRQoL, weight, and demographic characteristics of obese persons seeking or not seeking surgical or non-surgical treatment.

Nonresponse Among Ethnic Minorities: A Multivariate Analysis

Abstract: This article examines the nonresponse among ethnic minorities in the Netherlands. We have constructed a structural equation model with various response outcomes, controlling the effect of ethnicity on the response outcomes for various socio-economic and socio-demographic variables. The effect of ethnicity on response is almost entirely mediated by the degree of urbanization. We have also performed multiple group analyses to examine differences between ethnic groups in the response outcome predictors. Here again, we note that urbanization has a negative effect on the response probabilities in all the ethnic groups and in particular on the contact probabilities. This negative effect is somewhat larger, however, among sampled units with a non-Western background.

Retrospective questions or a diary method? A two-level multitrait-multimethod analysis

Abstract: This study describes a comparison between retrospective questions and daily diaries inquiring about positive and negative support in spousal interactions. The design was a multitrait-multimethod matrix with trait factors of positive and negative support, and method factors of retrospective questions and daily asked questions. Five questions were used for positive support and 2 questions were used for negative support. The data were multilevel, with daily measurement occasions nested within subjects. In addition, the data were ordered categorically. The negative support events proved to be so rare that the original 4-point response scale had to be dichotomized. The resulting model could be estimated using M plus, but the model and data complexities set some limits to the analysis. The results showed that at the subject level both positive and negative support could be assessed with sufficient reliability and validity. At the daily measurements level, positive support showed significant but low reliability ...