Factor structure of the Schalock and Keith Quality of Life Questionnaire (QOL-Q): validation on Mexican and Spanish samples

Background The Quality of Life Questionnaire (QOL-Q) is used widely to evaluate the quality of life of persons with intellectual disability (ID). Its validity for use with Spanish-speaking cultures has been demonstrated for individuals with visual disabilities, but not for those with physical or intellectual disabilities. Such was the purpose of the present study. Method Two samples were administered the QOL-Q under standardized procedures. The first sample was composed of 209 Mexican participants with physical disabilities; the second was composed of 424 Spanish participants with ID. The hypothesis tested was: the applicability (i.e. etic properties) of the measure across countries and respondents would be demonstrated if reliability data and if factor composition were similar to the original measure. Cronbach's alpha was used to test reliability and exploratory factor analyses were used to test validity (i.e. factor structure). Results Data indicated that the reliability and factor structure was similar to that reported in the questionnaire's standardization manual and consistent with that reported in a number of Anglo-Saxon countries. Conclusion The present study offers additional support for the valid use of the QOL-Q with Spanish-speaking populations.     

Quality of life for people with intellectual disabilities in China: a cross-culture perspectives study

Background The concept of quality of life (QOL) is explained on the basis of traditional Chinese culture and contemporary social and cultural trends. Method The importance of internationally recognized QOL domains and indicators was determined for three respondent groups: consumers, parents of the consumers, and teachers and rehabilitation professionals working with the clients. Results Principal component analysis confirmed seven factors influencing QOL for people with intellectual disabilities (ID) in China. These seven components are conceptually equivalent to the eight domains found in the international QOL literature. Conclusion The concept of QOL has become one of the most sensitive issues in present Chinese society and peoples’ lives, and an important theoretical framework for the education and rehabilitation for people with ID in several ways: curriculum development, service delivery models, education and rehabilitation practices, and employment models.     

Spanish adaptation and validation of the Family Quality of Life Survey

Background Assessing the quality of life (QOL) for families that include a person with a disability have recently become a major emphasis in cross-cultural QOL studies. The present study examined the reliability and validity of the Family Quality of Life Survey (FQOL) on a Spanish sample. Method and results The sample comprised 385 families who were administered the FQOL in Cali, Columbia. The FQOL showed adequate temporal stability (r = 0.68 on Importance and r = 0.78 on Satisfaction) and excellent internal consistency: Cronbach's alpha of 0.96 for Importance and 0.95 for Satisfaction. The confirmatory factor analysis yielded high fit indices, thus confirming that the factor structure of the FQOL as adapted for Spanish people fitted the five-factor model proposed by the survey's authors. Conclusions The study provides a valid instrument for the research of the QOL of those families that have a child with a disability within Spanish-speaking community.     

Psychometric properties of the Chinese-version Stroke and Aphasia Quality of Life Scale 39-generic version (SAQOL-39g)

Background and purpose: Aphasia is a common outcome of stroke affecting one-third of the post-stroke population in China. While the quality of life (QOL) may be affected, care is often inadequately guided due to lack of validated measure for Chinese population with stroke-induced aphasia. This study aimed to develop a Chinese-version of the Stroke and Aphasia Quality of Life-39 generic version (SAQOL-39g) and evaluate its feasibility, reliability, and validity in Chinese patients with stroke-induced aphasia.

Methods: The process of translation and adaptation suggested by WHO was used to develop the Chinese-version of SAQOL-39. We evaluated the feasibility, reliability, and validity of the scale in 84 aphasia patients and their proxies by assessing the internal consistency of the test items, test–retest consistency, and the structural validity of data.

Results: The self-report and the proxy-report form were completed within 21.4 and 13.3 min on average, respectively. Physical, communication, and psychological subdomains were extracted as three common factors. The Cronbach’s alpha coefficients of overall domain and subdomains for both forms ranged from 0.879 to 0.950, indicating high internal consistency. The intraclass correlation coefficients ranged from 0.804 to 0.987 for overall domain and subdomains of the forms. No significant difference was found between two forms.

Conclusions: The Chinese-version SAQOL-39g has excellent reliability, validity, and feasibility for measuring the QOL of Chinese post-stroke aphasia patients. The consistency between self-report and proxy-report forms was good, implying that the proxy-report form can be used to assess the QOL of post-stroke aphasia patients.     

The development and validation of the Dementia Quality of Life Scale for Older Family Carers (DQoL-OC)

Purpose: Little is known about how caregiving affects the quality of life (QoL) of older family carers and no dementia and age-specific QoL scale is available for use with this population. This study aimed to develop and validate a unique dementia caregiving- and age-specific tool – the ‘Dementia Quality of Life Scale for Older Family Carers’ (DQoL-OC).

Methods: The scale items were identified in focus groups with older family carers in the UK. Content and face validity were evaluated by a panel of six experts. A set of 100 items assessed on a 5-point Likert scale was tested with 182 older family carers. Test–re-test reliability was conducted with 18 individuals. Exploratory factor analysis was used to identify the QoL model and reduce the number of scale items. Convergent construct validity and internal consistency were also established.

Results: A one-factor solution containing 22 items was obtained. Test–re-test reliability (lower bound r = 0.835; p < 0.001), internal consistency (Cronbach's α = 0.936), and convergent construct validity were established. Significantly lower levels of QoL were found in female older carers; those who perceived their relatives with dementia as being at the earlier stages of the disease and with unstable dementia symptoms; those providing care more hours per day and more days per week; and those in younger-old age.

Conclusions: The DQoL-OC is a valid and reliable scale that will be useful for research and in clinical practice with older family carers of people with dementia. These study results will inform future health and social care aiming to improve life quality for this overlooked population of carers.     

Caregiver's Concerns-Quality of Life Scale (CC-QoLS): Development and evaluation of psychometric properties

We have developed a Caregiver's Concerns-Quality of Life Scale (CC-QoLS) for adults with intellectual disabilities (ID) who exhibit aggressive behaviour. The CC-QoLS is a brief (8 items in each subscale, CC and QoL respectively) proxy measure completed by caregivers. This is a specific health related quality of life instrument (HRQoL) combined with measures of caregiver's concerns for use as an outcome measure to assess clinical and cost effectiveness of interventions for aggression in adults with ID. The CC-QoLS was found to have good face validity and very good test–retest reliability with an ICC of 0.81 for CC (range 0.46–0.83 across items) and 0.80 for QoL (range 0.65–0.81 across items). Similarly, the scale had good inter-rater reliability with an ICC of 0.67 for CC (range 0.31–0.63 across items) and 0.63 for QoL (range 0.31–0.65 across items). Internal consistency for each subscale was also good (Cronbach's alpha was 0.85 for CC and 0.80 for QoL; Split-half Spearman–Brown was 0.81 for CC and 0.70 for QoL). Furthermore, the scale showed good concurrent validity with measures of severity of aggressive behaviour, namely Modified Overt Aggression Scale (MOAS) (CC: r = 0.4; p ≤ 0.01 and QoL: r = −0.2; p ≤ 0.05) and Aberrant Behavior Checklist-Irritability subscale (ABC-I) (CC: r = 0.5; p ≤ 0.01 and QoL: r = −0.02; p ≤ 0.05) as well as Caregiver's Uplift and Burden Scale score (<0.05). We believe that the CC-QoLS is a user friendly, easy to complete, first-ever HRQoL measure for adults with ID and aggressive behaviour with very good psychometric properties.     

The Life Satisfaction Matrix: an instrument and procedure for assessing the subjective quality of life of individuals with profound multiple disabilities

Background Assessing and measuring subjective quality of life (QOL) for individuals with profound multiple disabilities (PMD) remain amongst the most difficult challenges for theorists and practitioners in the field. The usual approaches using proxy reporting by familiar others have been demonstrated to be of questionable reliability and validity for persons with PMD. Method The author's continuing research into understanding the nature of subjective QOL of these individuals has led to the development and evaluating the Life Satisfaction Matrix (LSM), an instrument and procedure for assessing the subjective QOL of these individuals. Results Qualitative research that provides empirical evidence to support the assumptions underpinning, and face validity of, the LSM is described in this article. Conclusion Results of the study described herein demonstrate some potential to meet and overcome the above-mentioned challenges to assess and measure the subjective QOL of individuals with PMD.     

Individual planning: an exploration of the link between quality of plan and quality of life

Individual plans for people with intellectual disabilities were evaluated for quality and effectiveness in improving quality of life. Quality was assessed by rating whether goals were relevant, observable, age appropriate, necessary, timetabled, developmental, measurable, realistic, assigned to staff and improving at least one of O'Brien's five service accomplishments [ O'Brien & Tyne (1981) The principle of normalization: a foundation for effective services. London, Campaign for the Mentally Handicapped]. Effectiveness was assessed by examining quality of life outcomes for participants with and without individual plans rated as higher quality. No significant difference in outcomes associated with having a higher quality individual plan was found. Findings present a challenge to current expectations that presence and quality of individual plan goals are associated with improved outcomes. Written individual plan goals may not be directly correlated with actual practice, and further research is required to examine this.     

Validation of the Individualized Neuromuscular Quality of Life Questionnaire in Korean Patients With Genetic Neuromuscular Diseases

Background and PurposeThe Individualized Neuromuscular Quality of Life questionnaire (INQoL) is a widely used measure of the quality of life in patients with neuromuscular diseases. The purpose of this study was to translate and validate the Korean version of INQoL in Korean patients with neuromuscular diseases.MethodsWe translated the original INQoL version into Korean while applying appropriate language adaptations. The internal consistency, known-group validity, and test-retest reliability were also assessed. Construct validity was measured using the modified Rankin Scale (mRS) score and the manual muscle testing (MMT)-sum score based on the Medical Research Council scale, and concurrent validity was measured using the 36-item Short Form Survey (SF-36) questionnaire.ResultsThis study enrolled 193 patients. The coefficients for internal consistency (Cronbach’s α=0.805 to 0.987) and test-retest reliability (Spearman’s ρ=0.453 to 0.886) were adequately high for all subscales except in the ‘treatment effects’ dimension. INQoL subscales other than those for locking, droopy eyelids, double vision, and swallowing difficulties were significantly associated with their relevant SF-36 domains (Spearman’s ρ=-0.274 to -0.833). Functional status and muscle strength were most strongly associated with independence (Spearman’s ρ=0.753 and p<0.001 for mRS score, Spearman’s ρ=-0.741 and p<0.001 for MMT-sum score).ConclusionsThe Korean INQoL is a reliable and validated measurement tool for Korean patients with neuromuscular diseases.     

Quality of life in adults with an intellectual disability: the Evaluation of Quality of Life Instrument

Background The construct of quality of life (QoL) has been the focus of a great deal of recent research and has been operationalized in the assessment of the effectiveness of biomedical and rehabilitative interventions. Consequently, the effective measurement of QoL has become a relevant issue. QoL assessment should take account of both objective life conditions and reported satisfaction with those conditions, and should recognize that QoL has multiple domains. There is also evidence to suggest that it is useful to supplement such assessments with the evaluations of significant others within a multidimensional assessment perspective. Methods The current study describes a further stage of testing and refinement of the Evaluation of Quality of Life Instrument (EQLI), which was designed to elicit from staff of health and social care services assessments of the level of satisfaction experienced by adults with an intellectual disability. Specifically, the EQLI's internal consistency, and construct, convergent and discriminant validity were analysed. Results The EQLI appears to be a psychometrically valid measure for collecting data on the levels of satisfaction which, according to health and social services staff, might be experienced by individuals with an intellectual disability who attend residential institutions and community‐based day centres. The factor analyses supported a three‐factor structure for the EQLI and reliability estimates of scores on the three factors were in the moderate to high range. The data collected supported convergent and discriminant validity. Conclusions The results indicate that the EQLI is an effective measure for gaining staff perceptions of individuals who may be at risk of dissatisfaction with various QoL domains. The EQLI is as an instrument which, within a multidimensional assessment, could contribute to the identification of areas of user dissatisfaction with services.     

Psychometric evaluation of a questionnaire to measure the quality of life of people with profound multiple disabilities (QOL-PMD)

Because of a shortage of valid instruments to measure the QOL of people with profound multiple disabilities (PMD), the QOL-PMD was developed. In the present study, possibilities for item reduction as well as the psychometric properties of the questionnaire were examined. One hundred and forty-seven informants of people with PMD participated in the study. Fifty items were removed from the questionnaire on the basis of preset criteria. Internal consistency was good for the total questionnaire as well as for the subscales. Evidence of the construct validity of the questionnaire was found. Correspondence between the groups of informants was moderate. The results of this preliminary analysis of the psychometric properties of the QOL-PMD are encouraging, but further validation of the measure is warranted.     

Operationalizing quality of life for people with profound multiple disabilities: a Delphi study

Background In a recent study, we constructed an item pool that contains items on the quality of life (QOL) and related aspects of support of people with profound multiple disabilities (PMD). In the present study, a panel of experts assessed the content and the structure of this item pool in order to enhance its validity and usefulness. Method A two‐round Delphi study was set up. The panel consisted of 45 experts, of whom 12 were theory‐experts, 12 practice‐experts and 12 experience‐experts from Belgium (n = 12), Germany (n = 12), the Netherlands (n = 11) and the UK/Ireland (n = 10). Both quantitative and qualitative methods of analysis were applied to the data. Results The majority of the items were considered relevant for the QOL of people with PMD. In the first round, 91% of the items reached the 80% criterion of consensus. In the second round, 78.7% of the items reached the 85% criterion of consensus. There were no significant differences in opinion neither between types of experts nor between countries. Several items were reported as missing in the item pool and were added. Conclusions The results provide some evidence that the item pool is a valid operationalization of QOL of people with PMD and can be used in an instrument to measure the QOL of this target group.     

Possible error in the Danish version of the WHO Quality of Life (WHOQOL-BREF) Questionnaire

Background: The WHOQOL-BREF is widely used to measure quality of life.

Aims: The goal of the present study was to use the questionnaire in a doctoral study.

Methods: We studied all the instructions provided by the WHO.

Results: In the Danish version of the WHOQOL-BREF there is a discrepancy between the negatively phrased question 9 and both the syntax file and the verbal instructions for coding the data provided by the WHO.

Conclusions: This is a notification of possible error interpretations in projects that use the questionnaire. This could be corrected by manual correction in the coding process or by changing the negatively phrased question 9.     

Validation of the Subjective and Objective Family Burden Interview (SOFBI/ECFOS) in primary caregivers to adults with intellectual disabilities living in the community

Background There is little information on the psychometric properties of instruments for assessing family care burden in adults with intellectual disabilities (ID). The aim of this study is therefore to analyse the usefulness of the ‘Subjective and Objective Family Burden Interview’ (SOFBI) in the assessment of principal caregivers in Spain. Methods The SOFBI was administered to 166 principal caregivers of adults with ID in a vocational centre. The psychometric analysis included: internal consistency, inter‐rater and test–retest reliability, construct validity, convergent validity with the World Health Organization's Disability Assessment Schedule II, and feasibility. Results The Cronbach's alpha was 0.88 for the overall interview and always above 0.7 in the quantitative subdomains. The Kappa coefficients for test–retest were between 0.5 and 0.8, whereas inter‐rater agreement was nearly perfect. Maximum‐likelihood factor analysis showed four well‐defined factors, which fitted the previously designed domains. Feasibility was also good. Conclusions The SOFBI is a multi‐domain, modular instrument which is feasible, reliable and valid for measuring the burden of family caregivers to adults with ID living in the community.     

Quality of life in schizophrenia measured by the MOS SF-36 and the Lancashire Quality of Life Profile: a comparison

OBJECTIVE: To compare two Quality of Life (QoL) instruments on reliability, feasibility and conceptual overlap in a group of schizophrenic out-patients. METHOD: The Lancashire Quality of Life Profile (LQoLP) and the MOS SF-36 were used to assess the QoL of 143 schizophrenic out-patients. RESULTS: Feasibility and reliability for both instruments were satisfying. Second order factor analysis on 10 LQoLP and eight MOS SF-36 scales resulted in three factors: one health related QoL factor and two general QoL factors; an internal and an external factor. CONCLUSION: QoL measures in schizophrenia studies are not exchangeable. Validity of a specific QoL instrument depends upon the purpose of the study. The LQoLP allows suggestions for specific improvements in mental health care for long-term psychiatric patients. The SF-36 is a good choice when comparison with other patient groups on health related QoL is relevant.