Use of structural equation modeling to test the construct validity of the SF-36 Health Survey in ten countries: results from the IQOLA Project. International Quality of Life Assessment

Optimism on quality of life in Portuguese chronic patients: moderator/mediator?

Objective: optimism is an important variable that has consistently been shown to affect adjustment to quality of life in chronic diseases. This study aims to clarify if dispositional optimism exerts a moderating or a mediating influence on the personality traits-quality of life association, in Portuguese chronic patients. Methods: multiple regression models were used to test the moderation and mediation effects of dispositional optimism in quality of life. A sample of 729 patients was recruited in Portugal's main hospitals and completed self-reported questionnaires assessing socio-demographic and clinical variables, personality, dispositional optimism, quality of life (QoL) and subjective well-being (SWB). Results: the results of the regression models showed that dispositional optimism did not moderate the relationships between personality traits and quality of life. After controlling for gender, age, education level and severity of disease perception, the effects of personality traits on QoL and in SWB were mediated by dispositional optimism (partially and completely), except for the links between neuroticism/openness to experience and physical health. Conclusion: dispositional optimism is more likely to play a mediating, rather than a moderating role in personality traits-quality of life pathway in Portuguese chronic patients, suggesting that "the expectation that good things will happen" contributes to a better quality of life and subjective well-being.

Upstream and Downstream Correlates of Older People's Engagement in Social Networks: What are Their Effects on Health over Time?

This study tested the effects of social network engagement and social support on the health of older people moving into retirement, using a model which includes social context variables. A prospective survey of a New Zealand population sample aged 54–70 at baseline ( N = 2,282) was used to assess the effects on mental and physical health across time. A structural equation model assessed pathways from the social context variables through network engagement to social support and then to mental and physical health 2 years later. The proposed model of effects on mental health was supported when gender, economic living standards, and ethnicity were included along with the direct effects of these variables on social support. These findings confirm the importance of taking social context variables into account when considering social support networks. Social engagement appears to be an important aspect of social network functioning which could be investigated further.

Biological health or lived health: which predicts self-reported general health better?

BACKGROUND

Lived health is a person's level of functioning in his or her current environment and depends both on the person's environment and biological health. Our study addresses the question whether biological health or lived health is more predictive of self-reported general health (SRGH).

METHODS

This is a psychometric study using cross-sectional data from the Spanish Survey on Disability, Independence and Dependency Situation. Data was collected from 17,739 people in the community and 9,707 from an institutionalized population. The following analysis steps were performed: (1) a biological health and a lived health score were calculated for each person by constructing a biological health scale and a lived health scale using Samejima's Graded Response Model; and (2) variable importance measures were calculated for each study population using Random Forest, with SRGH as the dependent variable and the biological health and the lived health scores as independent variables.

RESULTS

The levels of biological health were higher for the community-dwelling population than for the institutionalized population. When technical assistance, personal assistance or both were received, the difference in lived health between the community-dwelling population and institutionalized population was smaller. According to Random Forest's variable importance measures, for both study populations, lived health is a more important predictor of SRGH than biological health.

CONCLUSIONS

In general, people base their evaluation of their own health on their lived health experience rather than their experience of biological health. This study also sheds light on the challenges of assessing biological health and lived health at the general population level.

Psychosocial factors as predictors of quality of life in chronic Portuguese patients

Background

Chronic illnesses are diseases of long duration and generally of slow progression. They cause significant quality of life impairment. The aim of this study was to analyse psychosocial predictors of quality of life and of subjective well-being in chronic Portuguese patients.

Methods

Chronic disease patients (n = 774) were recruited from central Portuguese Hospitals. Participants completed self-reported questionnaires assessing socio-demographic, clinical, psychosocial and outcome variables: quality of life (HRQL) and subjective well-being (SWB). MANCOVA analyses were used to test psychosocial factors as determinants of HRQL and SWB.

Results

After controlling for socio-demographic and clinical variables, results showed that dispositional optimism, positive affect, spirituality, social support and treatment adherence are significant predictors of HRQL and SWB. Similar predictors of quality of life, such as positive affect, treatment adherence and spirituality, were found for subgroups of disease classified by medical condition.

Conclusions

The work identifies psychosocial factors associated with quality of life. The predictors for the entire group of different chronic diseases are similar to the ones found in different chronic disease subgroups: positive affect, social support, treatment adherence and spirituality. Patients with more positive affect, additional social support, an adequate treatment adherence and a feel-good spirituality, felt better with the disease conditions and consequently had a better quality of life. This study contributes to understanding and improving the processes associated with quality of life, which is relevant for health care providers and chronic diseases support.

Predictors of quality of life in Portuguese obese patients: a structural equation modeling application

Living with obesity is an experience that may affect multiple aspects of an individual's life. Obesity is considered a relevant public health problem in modern societies. To determine the comparative efficacy of different treatments and to assess their impact on patients' everyday life, it is important to identify factors that are relevant to the quality of life of obese patients. The present study aims to evaluate, in Portuguese obese patients, the simultaneous impact of several psychosocial factors on quality of life. This study also explores the mediating role of stigma in the relationship between positive/negative affect and quality of life. A sample of 215 obese patients selected from the main hospitals in Portugal completed self-report questionnaires to assess sociodemographic, clinical, psychosocial, and quality of life variables. Data were analysed using structural equation modeling. The model fitted the data reasonably well, CFI = 0.9, RMSEA = 0.06. More enthusiastic and more active patients had a better quality of life. Those who reflect lower perception of stigma had a better physical and mental health. Partial mediation effects of stigma between positive affect and mental health and between negative affect and physical health were found. The stigma is pervasive and causes consequences for psychological and physical health.

Effectiveness of multidisciplinary rehabilitation treatment for patients with chronic pain in a primary health care unit

Background In recent years, multidisciplinary rehabilitation (MDR) became an alternative treatment option for chronic non-cancer pain. MDR is mostly available in specialized pain units, usually at rehabilitation centers where the level of knowledge and therapeutically options to treat pain conditions are considered to be high. There is strong evidence that MDR in specialized pain units is affecting pain and improves the quality of life in a sustainable manner. There are few studies about MDR outcome in primary health care, especially in those units situated in rural areas and with a different population than that encountered in specialized hospitals. That, in spite of the fact that the prevalence of pain in the patients treated in primary care practice is about 30%. The aim of this study is to analyze the effectiveness of MDR for chronic non-cancer patients in a primary health care unit. Methods This study included a total of 51 patients with chronic pain conditions who were admitted and completed the local MDR-program at the primary health care unit in Arvika, Sweden. The major complaint categories were fibromyalgia (53%), pain from neck and shoulder (28%) or low back pain (12%). The inclusion criteria were age between 16 and 67 years and chronic non-cancer pain with at least 3 months duration. The multidisciplinary team consisted of a general practitioner, two physiotherapists, two psychologists and one occupational therapist. The 6-week treatment took place in group sessions with 6-8 members each and included cognitive-behavioral treatment, education on pain physiology, ergonomics, physical exercises and relaxation techniques. Primary outcomes included pain intensity, pain severity, anxiety and depression scores, social and physical activity, and secondary outcomes were sick leave, opioid consumption and health care utilization assessed in the beginning of the treatment and at one year follow-up. Data was taken from the Swedish Quality Register for Pain Rehabilitation (SQRP) and the patients' medical journal. Results One year after MDR treatment, sick leave decreased from 75.6% to 61.5% (p <0.05). Utilization of health-care during one year decreased significantly from 27.4 to 20.1 contacts (p = 0.02). There were significant improvements concerning social activity (p = 0.03) and depression (p <0.05), but not in anxiety (p = 0.1) and physical activity (p = 0.08). Although not statistically significant, some numerical decrease in the mean levels of pain intensity, pain severity and opioid consumption were reported one year after MDR (p > 0.05). Conclusions The results obtained one year after rehabilitation indicated that patients with chronic noncancer pain might benefit from MDR in primary health care settings. Implications This study suggests that MDR in primary care settings as well as MDR at specialized pain units may lead to better coping in chronic non-cancer pain conditions with lower depression scores and higher social activity, leading to lower sick leave. This study demonstrated that there is a place for MDR in primary health care units with the given advantage of local intervention in rural areas allowing the patients to achieve rehabilitation in their home environment.

The SF-36v2 and SF-12v2 health surveys in New Zealand: norms, scoring coefficients and cross-country comparisons

OBJECTIVE

To provide New Zealand population norms for version 2 of the SF-36 and SF-12 health surveys and report scoring coefficients that enable the construction of Physical and Mental Component Summary scores from New Zealand SF-36v2 and SF-12v2 data.

APPROACH

Norms for the SF-36v2 and scoring coefficients for the Physical and Mental Component Summary scores are estimated using 2006/07 New Zealand Health Survey data, which included 12,488 adults (aged 15 years and over). Norms for the SF-12v2 are derived from 2008 New Zealand General Social Survey data, including 8,721 adults. Comparisons are made between New Zealand norms for versions 1 and 2 of the SF-36 instrument. In addition, New Zealand SF-36v2 and SF-12v2 norms and the scoring coefficients are compared with those for the United States and South Australia.

CONCLUSION

Differences between: 1) New Zealand population norms for the SF-36 versions 1 and 2; and 2) SF-36v2 and SF-12v2 population norms for New Zealand and those for the United States and South Australia highlight the importance of using version-specific and country-specific population norms.

IMPLICATIONS

The analysis reported here allows for the appropriate use of the SF-36v2 and SF-12v2 instruments in New Zealand.

Multidimensional item response theory models yielded good fit and reliable scores for the Short Form-12 questionnaire

OBJECTIVES

To propose a multidimensional item response theory (MIRT) scoring system for the Short Form 12 (SF-12) with good psychometric properties in terms of fit and reliability.

STUDY DESIGN AND SETTINGS

Two models, indicating physical (PCS) and mental component summary (MCS) dimensions, were fitted to SF-12 data from the European Study of the Epidemiology of Mental Disorders, a representative sample from European adult general population (n=21,425; response rate=61.2%). Goodness of fit, information, reliability, and agreement of individual scores were compared with the classical SF-12 and RAND-12 algorithms.

RESULTS

The bidimensional response process (BRP) model, where all items are indicators of both dimensions, yielded the best fit (root mean square error of approximation=0.057, comparative fit index=0.95, and Tucker-Lewis index=0.94), and highly agreed with PCS and MCS scores from the SF-12 (intraclass correlation coefficients of 0.92 and 0.88, respectively) and RAND-12 (0.88 and 0.95). Regarding reliability, the BRP yielded 0.75 and 0.77 (PCS and MCS, respectively), greater than SF-12 (0.65 and 0.66) and RAND-12 (0.65 and 0.67). As indicated by scale linking, MIRT scores can be interpreted similarly to the classical scores.

CONCLUSION

The MIRT models showed a clear construct structure for the PCS and MCS dimensions, defined by functional and role limitation content. Results support the use of SF-12 MIRT-based scores as a valid and reliable option to assess health status.

Inner strength in relation to perceived physical and mental health among the oldest old people with chronic illness

OBJECTIVES

The aim of this study was to examine inner strength, defined as connectedness, firmness, flexibility, and creativity, and its relation to mental and physical health in a sample of the oldest old chronically ill women and men living at home.

METHODS

A sample of 79 older women and 41 men in the age range of 80-101 years old (mean = 87.5) participated in this study. Inner strength measured by Resilience Scale, Sense of Coherence Scale (SOC), Purpose in Life Test (PIL), and Self-Transcendence Test (STS) was viewed in relation to mental and physical health (SF-36 Health Survey).

RESULTS

Experiencing connectedness, firmness, flexibility, and creativity were equal for women and men. SOC, PIL, and STS showed moderate inner strength. Medium and low resilience made the participants feel vulnerable. A significant correlation was observed between the variables for inner strength and mental health for women, men, and the total sample. STS was associated with mental and physical health for the total sample and for women.

CONCLUSIONS

Although the oldest old women and men were vulnerable, they had inner strength. Encouraging participation using the inner strength of the oldest old can contribute to strengthen their experiences of independence, integrity, and enjoying life.

Validity and Reliability of MOS Short Form Health Survey (SF-36) for Use in India

BACKGROUND

Health is defined as the state of complete physical, mental and social well-being than just the absence of disease or infirmity. In order to measure health in the community, a reliable and validated instrument is required.

OBJECTIVES

To adapt and translate the Medical Outcomes Study Short-Form Health Survey (SF-36) for use in India, to study its validity and reliability and to explore its higher order factor structure.

MATERIALS AND METHODS

Face-to-face interviews were conducted in 184 adult subjects by two trained interviewers. Statistical analyses for establishing item-level validity, scale-level validity and reliability and tests of known group comparison were performed. The higher order factor structure was investigated using principal component analysis with varimax rotation.

RESULTS

The questionnaire was well understood by the respondents. Item-level validity was established using tests of item internal consistency, equality of item-scale correlations and item-discriminant validity. Tests of scale-level validity and reliability performed well as all the scales met the required internal consistency criteria. Tests of known group comparison discriminated well across groups differing in socio-demographic and clinical variables. The higher order factor structure was found to comprise of two factors, with factor loadings being similar to those observed in other Asian countries.

CONCLUSION

The item-and scale-level statistical analyses supported the validity and reliability of SF-36 for use in India.

Measurement bias of the SF-36 Health Survey in older adults with chronic conditions

PURPOSE

The objectives of this study were to investigate the psychometric properties of the SF-36 in a sample of older adults with chronic conditions and to test whether measurement bias exists based on the levels of comorbidity.

METHODS

Participants included were 979 cognitively intact older adults with comorbidities who were interviewed at their homes. We examined the psychometric properties of the SF-36 and conducted confirmatory factor analysis (CFA) to investigate the assumption of measurement invariance by the levels of comorbidity.

RESULTS

Overall data quality was high and scaling assumptions were generally met with few exceptions. Floor and ceiling effects were present for the role-physical and role-emotional subscales. Using CFA, we found that a three-factor measurement model fits the data well. We identified two violations of measurement invariance. Results showed that participants with high comorbidity level place more emphasis on social functioning (SF) and bodily pain (BP) in relation to physical health-related quality of life (HRQoL) than those with low comorbidity level.

CONCLUSIONS

Measurement bias was present for the SF and BP components of the SF-36 physical HRQoL measure. Researchers should be cautious when considering the use of SF-36 in clinical studies among older adults with comorbidities.

Quality of life among healthcare workers: a multicentre cross-sectional study in Italy

OBJECTIVE

To evaluate the quality of life among doctors, nurses, and occupational safety and health technologists (OSHT).

STUDY DESIGN

Cross-sectional study was undertaken in a population of healthcare workers in 10 Italian regions.

METHODS

The Italian version of short form-36 (SF-36) was anonymously and voluntarily self-administered by participants to assess the perceived health-related quality of life (HRQOL). The HRQOL scores for the sample and the Italian population were compared. A multiple linear regression was performed to assess the influence of age, gender, role, socializing time, working time, years spent in healthcare and years spent in the specific department on the SF-36 score.

RESULTS

The sample included 324 healthcare workers [57.1% women, mean age 39.0 (standard deviation 10.2) years]: 52.6% were medical doctors, 36.8% were nurses and 10.5% were OSHTs. Workers with a career of >15 years achieved a general health score lower than that of workers with a shorter career, while those who spent more time in socializing activities achieved a higher mental health score. The multivariate analysis showed that increasing age is positively related to role emotional levels (β = 0.243; P = 0.002), while it appears to be inversely related to general health (β = -0.218; P = 0.007) and physical function (β = -0.246; P = 0.001). Nurses had lower scores for bodily pain (β = -0.214; P < 0.001), social function (β = -0.242; P = 0.001) and role emotional (β = -0.211; P = 0.006) compared with doctors. Compared with the general Italian population, healthcare workers had higher scores for general health, physical function, role physical, bodily pain and mental health, and lower scores for vitality, social function and role emotional.

CONCLUSIONS

Healthcare workers have different levels of HRQOL related to their professional role. In particular, nurses have lower quality of life. These results may help to identify the main roles and attitudes that could cause frustration, dissatisfaction and emotional stress in healthcare workers.

Measurement equivalence of the SF-36 in the Canadian Multicentre Osteoporosis Study

BACKGROUND

Studies that compare health-related quality of life (HRQOL) and other patient-reported outcomes in different populations rest on the assumption that the measure has equivalent psychometric properties across groups. This study examined the measurement equivalence (ME) of the 36-item Medical Outcomes Study Short Form Survey (SF-36), a widely-used measure of HRQOL, by sex and race in a population-based Canadian sample.

FINDINGS

SF-36 data were from the Canadian Multicentre Osteoporosis Study, a prospective cohort study that randomly sampled adult men and women from nine sites across Canada. Confirmatory factor analysis (CFA) techniques were used to test hypotheses about four forms of ME, which are based on equality of the factor loadings, variances, covariances, and intercepts. Analyses were conducted for Caucasian and non-Caucasian females (n = 6,539) and males (n = 2,884). CFA results revealed that a measurement model with physical and mental health factors provided a good fit to the data. All forms of ME were satisfied for the study groups.

CONCLUSIONS

The results suggest that sex and race do not influence the conceptualization of a general measure of HRQOL in the Canadian population.

The Spanish SF-36 in Peru: factor structure, construct validity, and internal consistency

This study assessed the psychometric properties of the SF-36 questionnaire in a sample of 4344 Peruvian people aged 15 to 64 years. Internal consistency reliability was estimated using Cronbach's α coefficient, construct validity by known-groups comparison defined with respect to key sociodemographic characteristics, and factor structure by confirmatory factor analysis (CFA) at item level. Cronbach's α coefficient for the full questionnaire was 0.82 and ranged between 0.66 and 0.92 by scales. The 8 scales discriminated well between sexes, age, and socioeconomic groups. CFA showed that a model with 8 first-order factors and 2 second-order factors (namely, physical and mental health) was a feasible representation of the SF-36 factor structure and had better fit to data than alternative factor structures. The SF-36 showed appropriate psychometric properties regarding internal consistency, construct validity, and factor structure when tested in Peru. Future studies should focus on testing other psychometric properties of the SF-36, such as convergent and discriminant validity, test-retest reliability, and sensitivity to change.

Measuring disparities: bias in the Short Form-36v2 among Spanish-speaking medical patients

BACKGROUND

Many national surveys have found substantial differences in self-reported overall health between Spanish-speaking Hispanics and other racial/ethnic groups. However, because cultural and language differences may create measurement bias, it is unclear whether observed differences in self-reported overall health reflect true differences in health.

OBJECTIVES

This study uses a cross-sectional survey to investigate psychometric properties of the Short Form-36v2 for subjects across 4 racial/ethnic and language groups. Multigroup latent variable modeling was used to test increasingly stringent criteria for measurement equivalence.

SUBJECTS

Our sample (N=1281) included 383 non-Hispanic whites, 368 non-Hispanic blacks, 206 Hispanics interviewed in English, and 324 Hispanics interviewed in Spanish recruited from outpatient medical clinics in 2 large urban areas.

RESULTS

We found weak factorial invariance across the 4 groups. However, there was no evidence for strong factorial invariance. The overall fit of the model was substantially worse (change in Comparative Fit Index >0.02, root mean square error of approximation change >0.003) after requiring equal intercepts across all groups. Further comparisons established that the equality constraints on the intercepts for Spanish-speaking Hispanics were responsible for the decrement to model fit.

CONCLUSIONS

Observed differences between SF-36v2 scores for Spanish-speaking Hispanics are systematically biased relative to the other 3 groups. The lack of strong invariance suggests the need for caution when comparing SF-36v2 mean scores of Spanish-speaking Hispanics with those of other groups. However, measurement equivalence testing for this study supports correlational or multivariate latent variable analyses of SF-36v2 responses across all the 4 subgroups, as these analyses require only weak factorial invariance.

[Reconstituting evaluation methods based on both qualitative and quantitative paradigms]

Debate about the relationship between quantitative and qualitative paradigms is often muddled and confusing and the clutter of terms and arguments has resulted in the concepts becoming obscure and unrecognizable. In this study we conducted content analysis regarding evaluation methods of qualitative healthcare research. We extracted descriptions on four types of evaluation paradigm (validity/credibility, reliability/credibility, objectivity/confirmability, and generalizability/transferability), and classified them into subcategories. In quantitative research, there has been many evaluation methods based on qualitative paradigms, and vice versa. Thus, it might not be useful to consider evaluation methods of qualitative paradigm are isolated from those of quantitative methods. Choosing practical evaluation methods based on the situation and prior conditions of each study is an important approach for researchers.

A measurement model for general noise reaction in response to aircraft noise

In this paper a measurement model for general noise reaction (GNR) in response to aircraft noise is developed to assess the performance of aircraft noise annoyance and a direct measure of general reaction as indicators of this concept. For this purpose GNR is conceptualized as a superordinate latent construct underlying particular manifestations. This conceptualization is empirically tested through estimation of a second-order factor model. Data from a community survey at Frankfurt Airport are used for this purpose (N=2206). The data fit the hypothesized factor structure well and support the conceptualization of GNR as a superordinate construct. It is concluded that noise annoyance and a direct measure of general reaction to noise capture a large part of the negative feelings and emotions in response to aircraft noise but are unable to capture all relevant variance. The paper concludes with recommendations for the valid measurement of community reaction and several directions for further research.

Assessment of the Chinese-version SF-36 in the Chinese opiate addicts

This study was designed to assess the reliability and validity of the Chinese version of the Medical Outcomes Study Short Form 36 (SF-36) assessed with opiate addicts in China. The sample was composed of 442 questionnaires from three regions in China, in 2004. The reliability of Chinese-version SF-36 was obtained using Cronbach's α and split-half coefficients and the validity was calculated using correlation analysis and confirmatory factor analysis method. The results of reliability and validity provide the first evidence that Chinese-version SF-36 is validated for Chinese addicts. The study's limitations are noted.

Confirmatory factor analysis of the validity of the SF-12 for persons with and without a history of stroke

PURPOSE

To assess the validity of the Physical and Mental Component Summary scores (PCS and MCS) of the 12-item Short-Form Health Survey (SF-12), a measure of health-related quality of life (HRQoL), among persons with a history of stroke.

METHODS

Persons with (n = 2,581) and without (n = 38,066) a reported history of stroke were enrolled in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study. Confirmatory factor analysis methods were used to evaluate the fit of a 2-factor model that underlies the PCS and MCS and to examine the equivalence of the factors across both study groups.

RESULTS

The 2-factor model provided good fit to the data among individuals with and those without a self-reported history of stroke. Item factor loadings were found to be largely invariant across both groups, and correlational analyses confirmed that the two latent factors were highly related to the PCS and MCS scores, calculated by the standard scoring algorithms. The effect of stroke history on physical health was more than twice its effect on mental health.

CONCLUSIONS

The psychometric measurement model that underlies the PCS and MCS summary scores is comparable between persons with and without a history of stroke. This suggests that the SF-12 has adequate validity for measuring HRQoL not only in the general population but also in cohorts following stroke.

Social support and psychological adjustment to SARS: the mediating role of self-care self-efficacy

The study tested the model of perceived support from medical staff and family/friends on severe acute respiratory syndrome (SARS) survivors' mental health as mediated by self-care self-efficacy. One hundred and forty-three SARS survivors recruited from the Hong Kong Hospital Authority following 18 months recovery were surveyed by trained interviewers using structured questionnaires. Based on structural equation modeling, findings showed that self-care self-efficacy completely mediated the effects of perceived medical staff support and perceived family/friends support on mental health status. The model achieved a satisfactory fit, CFI = 0.98, NNFI = 0.98, RMSEA = 0.06, and explained 75.2% of the variance in mental health status. The study is the first attempt in understanding long-term psychological adjustment of SARS survivors. Findings may be applicable to other infectious disease outbreaks in informing psychosocial factors that are important to long-term recovery.

Development of a Web-based concept for patients with ulcerative colitis and 5-aminosalicylic acid treatment

BACKGROUND

Ulcerative colitis (UC) is a lifelong disease with increasing incidence. UC requires frequent outpatient clinic visits and continuous medical treatment. Web-based self-management in other chronic diseases influences disease course, and increases self-adherence, compliance and quality of life (QoL). Lack of easy access to inflammatory bowel disease clinics and patient education, their understanding of the importance of early treatment at relapse, poor compliance and self-adherence can be partly solved by a newly developed Web-based concept.

AIMS

To describe the development and validation of the Web-based 'Constant-Care' concept.

METHODS

A Web-based treatment program (www.constant-care.dk) and a Patient Educational Centre for UC patients were developed. The feasibility and acceptance of the concept was validated before (group A) and 6 months after (group B) the start of a randomized controlled trial. Patients' level of disease-specific knowledge, QoL, anxiety and depression were evaluated.

RESULTS

Ten (group A) and 11 (group B) patients fulfilling the diagnostic criteria of mild-to-moderate UC participated in the study. All patients reported an ability to initiate self-treatment after the educational training (ET). A significant increase in knowledge from 36 to 69% (group A) and 28 to 75% (group B) was obtained. A majority of the patients were satisfied with the ET. Patients' QoL, anxiety, depression and general well-being showed no difference after the ET.

CONCLUSION

Patient education and training through a Web-based program (www.constant-care.dk) seems to be a feasible concept for increasing patients' ability to self-initiate treatment and increase the level of disease-specific knowledge. Relevant adjustment of the concept was implemented. The final outcome of the 'Constant-Care' concept is pending.

Dimensionality and summary measures of the SF-36 v1.6: comparison of scale- and item-based approach across ECRHS II adults population

OBJECTIVES

The objective of this study was twofold: 1) to confirm the hypothetical eight scales and two-component summaries of the questionnaire Short Form 36 Health Survey (SF-36), and 2) to evaluate the performance of two alternative measures to the original physical component summary (PCS) and mental component summary (MCS).

METHODS

We performed principal component analysis (PCA) based on 35 items, after optimal scaling via multiple correspondence analysis (MCA), and subsequently on eight scales, after standard summative scoring. Item-based summary measures were planned. Data from the European Community Respiratory Health Survey II follow-up of 8854 subjects from 25 centers were analyzed to cross-validate the original and the novel PCS and MCS.

RESULTS

Overall, the scale- and item-based comparison indicated that the SF-36 scales and summaries meet the supposed dimensionality. However, vitality, social functioning, and general health items did not fit data optimally. The novel measures, derived a posteriori by unit-rule from an oblique (correlated) MCA/PCA solution, are simple item sums or weighted scale sums where the weights are the raw scale ranges. These item-based scores yielded consistent scale-summary results for outliers profiles, with an expected known-group differences validity.

CONCLUSIONS

We were able to confirm the hypothesized dimensionality of eight scales and two summaries of the SF-36. The alternative scoring reaches at least the same required standards of the original scoring. In addition, it can reduce the item-scale inconsistencies without loss of predictive validity.

Inference from Multiple Imputation for Missing Data Using Mixtures of Normals

We consider two difficulties with standard multiple imputation methods for missing data based on Rubin's t method for confidence intervals: their often excessive width, and their instability. These problems are present most often when the number of copies is small, as is often the case when a data collection organization is making multiple completed datasets available for analysis. We suggest using mixtures of normals as an alternative to Rubin's t. We also examine the performance of improper imputation methods as an alternative to generating copies from the true posterior distribution for the missing observations. We report the results of simulation studies and analyses of data on health-related quality of life in which the methods suggested here gave narrower confidence intervals and more stable inferences, especially with small numbers of copies or non-normal posterior distributions of parameter estimates. A free R software package called MImix that implements our methods is available from CRAN.

Long-term outcome of patients with hereditary hemorrhagic telangiectasia and severe hepatic involvement after orthotopic liver transplantation: a single-center study

Hepatic involvement occurs in up to 74% of patients with hereditary hemorrhagic telangiectasia (HHT) and is characterized by a spectrum of arteriovenous malformations. Three different types of intrahepatic shunting may be present: hepatic artery to hepatic veins, hepatic artery to portal vein, and portal vein to hepatic vein. Hepatic involvement in HHT may lead to biliary ischemia, portal hypertension, or high-output cardiac failure (HOCF). Orthotopic liver transplantation (OLT) has been proposed as the only definitive curative treatment. The aim of this study was to evaluate the long-term outcome of patients with hepatic involvement due to HHT after OLT with respect to mortality, cardiac and hepatic status, epistaxis, and quality of life. Patients with HHT and severe hepatic vascular malformations who underwent OLT in the Lyon Liver Transplant Unit (LLTU) from 1993 to 2007 were followed at the LLTU and the French Reference Center for HHT. Quality of life was evaluated with the Short Form 36 questionnaire. There were 13 patients who fulfilled the entry criteria of the study (12 women and 1 man). The mean age at the time of OLT was 51.8 years (range = 33-65 years). Indications for OLT were cardiac failure (n = 9), biliary necrosis (n = 2), both cardiac failure and biliary necrosis (n = 1), and hemobilia (n = 1). The mean duration of follow-up was 109 months (range = 1-200 months). Twelve patients (92.3%) are still alive. For the 9 patients with HOCF, the mean cardiac index decreased from 5.4 L/minute/m(2) before OLT to 3.0 L/minute/m(2) after OLT. No severe hepatic complications were observed after OLT. Nine of the surviving patients (75%) experienced dramatic improvements in epistaxis and quality of life, including an ability to undertake more physical activity. In conclusion, OLT is an important therapeutic option for patients with HHT who have severe hepatic involvement. In the reported cohort, the mortality after OLT for this indication was low.

The effect of cognitive behavior therapy-based psychotherapy applied in a forest environment on physiological changes and remission of major depressive disorder

OBJECTIVE

Psychotherapeutic intervention combined with pharmacotherapy is helpful for achieving remission of depressive disorder. We developed and tested the effect of cognitive behavior therapy (CBT)-based psychotherapy applied in a forest environment on major depressive disorder.

METHODS

We performed 4 sessions during 4 weeks (3 hours/session) in patients with major depressive disorder during pharmacotherapy. For the forest group, sessions were performed in the forest; for the hospital group, sessions were performed in the hospital. The control group was treated with the usual outpatient management.

RESULTS

A total of 63 patients completed the study: 23 in the forest group, 19 in the hospital group, and 21 in the control group. Hamilton Rating Scales for Depression (HRSD) scores of the forest group were significantly decreased after 4 sessions compared with controls. Montgomery-Asberg Depression Rating Scales (MADRS) scores of the forest group were significantly decreased compared with both the hospital group and the controls. The remission rate (7 and below in HRSD) of the forest group was 61% (14/23), significantly higher than both the hospital group (21%, 4/19) and the controls (5%, 1/21). In heart rate variability (HRV) analysis, some measurements representing HRV and parasympathetic nerve tone were increased in the forest group after 4 sessions. The salivary cortisol levels of the forest group were significantly decreased.

CONCLUSION

CBT-based psychotherapy applied in the forest environment was helpful in the achievement of depression remission, and its effect was superior to that of psychotherapy performed in the hospital and the usual outpatient management. A good environment such as a forest helps improve the effect of psychotherapeutic intervention because it includes various natural instruments and facilitators in the treatment of depression.

Satisfactory cross-cultural validity of the ACTG symptom distress module in HIV-1-infected antiretroviral-naive patients

BACKGROUND

Multinational clinical trials commonly include different language versions of patient-reported outcomes (PRO) instruments without considering the question of their cross-cultural validity. The inclusion of a PRO instrument, the Adult AIDS Clinical Trial Group Symptom Distress Module (SDM), in an multinational clinical trial in HIV-1 antiretroviral-naive patients offered an opportunity to explore the methods to assess cross-cultural validity of PRO instruments in the context of clinical trials.

PURPOSE

To assess the cross-cultural validity of the SDM across seven cultural groups in the setting of a multinational HIV clinical trial.

METHODS

Twenty-five language versions of the SDM were included in a Phase IIb/III trial comparing maraviroc with efavirenz (each in combination with zidovudine/ lamivudine) conducted in 12 countries to assess symptoms perceived by HIV-1-infected antiretroviral-naive patients. Differential item functioning (DIF) detection and the STATIS method were combined in a pragmatic approach to assess the cross-cultural validity of the SDM using pre-antiretroviral treatment data from 759 patients.

RESULTS

Statistically significant DIF between cultural groups was observed for four items: fatigue; fevers; anxiety; and headache. However, examination of these items by linguists did not lead to meaningful explanations for the statistical differences. With the STATIS approach, the Bantu and European Germanic groups were the furthest from the Occidental English group.

LIMITATIONS

The assessment of cross-cultural validity had to be performed on some very small samples and on data aggregated by cultural groups, which suggests the need for a cautious interpretation of the results.

CONCLUSIONS

Given the heterogeneity of cultures considered, the absence of meaningful explanations for statistically significant differences between cultural groups supports the cross-cultural validity of the SDM versions included in this trial. Thus, this study demonstrated that it is feasible to conduct assessment of crosscultural validity of PRO instruments using data collected in the setting of multinational clinical trials.

Factorial structure and cross-cultural invariance of the Oral Impacts on Daily Performances

The issue of cross-cultural construct validation and measurement invariance of the Oral Impacts on Daily Performances (OIDP) questionnaire is important. Using confirmatory factor analysis (CFA), this study evaluated a proposed three-factor structure of the OIDP questionnaire in Tanzanian adolescents and adults and assessed whether this model would be replicated in Ugandan adolescents. Between 2004 and 2007, OIDP data were collected from 1,601 Tanzanian adolescents, 1,031 Tanzanian adults, and 1,146 Ugandan adolescents. Model generation analysis was restricted to Tanzanian adolescents, and the model achieved was tested, without modification, in Tanzanian adults and in Ugandan adolescents. A modified three-factor solution with cross-loadings improved the fit of the OIDP model to the data compared with a one-factor model and the original three-factor model within the Tanzanian [comparative fit index (CFI) = 0.99] and Ugandan (CFI = 0.98) samples. Cross-validation in Tanzanian adults provided a reasonable fit (CFI = 0.98). Multiple-group CFA demonstrated acceptable fit [chi(2) = 140.829, degrees of freedom (d.f.) = 24, CFI = 0.98] for the unconstrained model, whereas unconstrained and constrained models were statistically significantly different. Factorial validity was confirmed for the three-factor OIDP model. The results provide evidence for cross-cultural equivalence of the OIDP, suggesting that this measure is comparable, at least to some extent, across Tanzanian and Ugandan adolescents.

Factors associated with self-assessed oral health in the Japanese independent elderly

OBJECTIVES

The purpose of this research was to analyse the relationship between oral health status, oral motor function, daily life situations and self-assessed oral health.

MATERIALS AND METHODS

A cross-sectional survey was conducted on 190 independent elderly volunteers aged 62-99 years from senior citizen centres in Tokyo, Japan. A questionnaire survey and oral examination were conducted on each participant. For the descriptive analyses, Independent t-test and the chi-squared test were used. Following that, using four latent variables, (oral health, oral function, daily life situations and chronic health condition), a structural equation modelling analysis (SEMA) was undertaken.

RESULTS

In the descriptive analyses, there were no significant differences between self-assessed oral health and oral health status. However, there were significant differences between self-assessed oral health and oral function and daily life situations. Findings from SEMA revealed that daily life situations and oral function have independent effects on self-assessed oral health and that the relationship between self-assessed oral health and oral health status was weak.

CONCLUSIONS

Many factors affect self-assessed oral health status. Dental clinicians and researchers should attempt to understand these factors and incorporate them into effective personal and population-based oral health education and oral health promotion programmes.

The factor structure of the SF-36 in Parkinson's disease

RATIONALE, AIMS AND OBJECTIVES

The concept of quality of life (QoL) has emerged as an important psychological dimension in individuals experiencing Parkinson's disease (PD). The current study sought to determine the factor structure of the Medical Outcomes Study Short-Form 36 (SF-36) version 2 in patients with PD in order to evaluate how this measure might best be used to assess QoL in this clinical population.

METHOD

Confirmatory factor analyses were conducted on self-report SF-36 data from 339 individuals diagnosed with PD. Six structural models of the SF-36 were evaluated against the participants' data.

RESULTS

The underlying factor structure of the SF-36 in PD was observed to be inconsistent with the assumed measurement model of SF-36 but consistent with contemporary theoretical models of the instrument.

CONCLUSIONS

The use of the SF-36 in individuals with PD can be recommended when eight subscales are used and reported. Evidence to support the use of the instrument as a two-subscale measure of physical health and mental health components was not found.

Health effects of ownership of and attachment to companion animals in an older population

BACKGROUND

Two reasons for the inconclusiveness of the literature on the health effects of pet ownership are (1) failure to control for other known influences on health, and (2) inadequate consideration of the nature of the emotional relationship between owners and their companion animals.

PURPOSE

The main aims were to develop a measure of pet attachment that reflects psychologists' use of the attachment concept, and to see if pet ownership or attachment added to the health variance explained by known predictors.

METHOD

Community-living older adults (n = 314) gave information by interview using structured questions and standardized scales. Multiple regressions were then conducted to examine the possible predictive role of health habits, human social supports, pet ownership, and owners' attachment to the pet, on health and well-being.

RESULTS

The pet attachment measure showed good internal reliability. After controlling for other variables, neither pet ownership nor pet attachment added significantly to explained variance in health and well-being.

CONCLUSIONS

The health of elderly people is related to their health habits and social supports but not to their ownership of, or attachment to, a companion animal.

Health-related quality of life in community-dwelling older Whites and African Americans

OBJECTIVE

This study assesses structural and functional characteristics of Short Form-36 Health Survey (SF-36) domains using community-based samples of older Whites and African Americans. Although the eight domains of the SF-36 have by convention been collapsed into two summary categories- physical health and mental health-the authors examine a three-factor model including physical health, mental health, and general well-being. They hypothesized that the general well-being factor would be a mediator between physical and mental health in both groups.

METHOD

Analyses using structural equation modeling provide support for the approach.

RESULTS

In both White and African American samples, the three-factor model demonstrated a better fit than the two-factor model. Also, in both groups, general well-being mediated the relationship between physical health and mental health.

DISCUSSION

Findings suggest that general well-being serves as an intervening step between physical and mental health in both White and African American older adults.

Comparison between exploratory factor-analytic and SEM-based approaches to constructing SF-36 summary scores

OBJECTIVE

To compare the two higher order factor structures of the Short-Form 36 (SF-36) Health Survey, using exploratory factor analytic methods and structural equation modeling (SEM).

METHODS

Two population data sets were used. A stratified representative sample (n = 1,005) of the Greek general population was approached for interview. This survey containing the SF-36 was used to obtain component score coefficients from principal components analysis and orthogonal rotation. These coefficients were then used in the second data set (n = 1,007) of the Greek adult general population to compute scores for the physical component summary and the mental component summary of the SF-36. The second data set was also used to obtain factor scores for physical and mental health measures, applying SEM.

RESULTS

Exploratory factor analysis supported the existence of two principal components that are the basis for summary physical and mental health measures. SEM showed that models assuming that physical and mental health are correlated provided a better fit to the data than models assuming independence between physical and mental health. However, all eight dimensions of SF-36 should be included in the construction of summary scores.

CONCLUSIONS

These results confirm the multidimensional structure of the SF-36, the correlational equivalence between standard summary measures and SEM-based second-order factor scores, and underscore the feasibility of multinational comparisons of health status using this instrument.

Perceived health change in the aftermath of a petrochemical accident: an examination of pre-accident, within-accident, and post-accident variables

BACKGROUND

Little research has been conducted on changes in perceived health after an industrial accident. Using data from an ongoing survey on stress and health in a petrochemical complex in Texas City, Texas, the associations of a petrochemical accident with perceived health changes were examined.

METHODS

The mean changes in perceived mental and physical health across pre-accident, within-accident, and post-accident categories were compared. The association of these categorical variables with the change in perceived mental and physical health using multiple regression was also examined.

RESULTS

Significant declines in both perceived mental and physical health were observed for the sample. Regression analyses showed that middle age, lower education level and reported damage in the neighbourhood were associated with decreases in perceived mental health. Lower education level, explosion impact, and distance from the explosion site were associated with decreases in perceived physical health.

CONCLUSIONS

These results indicate that both pre-accident and within-accident variables, such as education level and explosion impact, are associated with decreases in perceived physical and mental health. Even a modest event within the range of accidents and disasters was shown to be associated with negative health outcomes for a population-based sample.

Evaluating the SF-36 Health Survey (Version 2) in Older Vietnamese Americans

OBJECTIVE

The SF-36((R)) Health Survey (Version 2; SF-36) was evaluated among older Vietnamese Americans to determine whether underlying dimensions of physical and mental health were similar to those of other groups in the United States.

METHOD

Field testing of participants from senior centers.

RESULTS

The study provided support for the reliability and validity of the SF-36. Structural equation modeling provided confirmation of physical and mental health factors. However, the factor loadings for the SF-36 scales were more consistent with previous results from Asian countries than the typical pattern observed in the United States.

DISCUSSION

As the older populations in the United States become more diverse, it is important to have standardized health-related quality of life measures. However, the conceptualization of physical and mental health and associations among different scales may be different for Asian immigrants than for other groups. Thus, the interpretation of the SF-36 scores needs to account for cultural differences.