Applying multidimensional computerized adaptive testing to the MSQOL-54: a simulation study.

BACKGROUND: The Multiple Sclerosis Quality of Life-54 (MSQOL-54) is one of the most commonly-used MS-specific health-related quality of life (HRQOL) measures. It is a multidimensional, MS-specific HRQOL inventory, which includes the generic SF-36 core items, supplemented with 18 MS-targeted items. Availability of an adaptive short version providing immediate item scoring may improve instrument usability and validity. However, multidimensional computerized adaptive testing (MCAT) has not been previously applied to MSQOL-54 items. We thus aimed to apply MCAT to the MSQOL-54 and assess its performance. METHODS: Responses from a large international sample of 3669 MS patients were assessed. We calibrated 52 (of the 54) items using bifactor graded response model (10 group factors and one general HRQOL factor). Then, eight simulations were run with different termination criteria: standard errors (SE) for the general factor and group factors set to different values, and change in factor estimates from one item to the next set at < 0.01 for both the general and the group factors. Performance of the MCAT was assessed by the number of administered items, root mean square difference (RMSD), and correlation. RESULTS: Eight items were removed due to local dependency. The simulation with SE set to 0.32 (general factor), and no SE thresholds (group factors) provided satisfactory performance: the median number of administered items was 24, RMSD was 0.32, and correlation was 0.94. CONCLUSIONS: Compared to the full-length MSQOL-54, the simulated MCAT required fewer items without losing precision for the general HRQOL factor. Further work is needed to add/integrate/revise MSQOL-54 items in order to make the calibration and MCAT performance efficient also on group factors, so that the MCAT version may be used in clinical practice and research.

Dementia-related genetic variants in an Italian population of early-onset Alzheimer's disease.

Early-onset Alzheimer's disease (EOAD) is the most common form of early-onset dementia. Although three major genes have been identified as causative, the genetic contribution to the disease remains unsolved in many patients. Recent studies have identified pathogenic variants in genes representing a risk factor for developing Alzheimer's disease (AD) and in causative genes for other degenerative dementias as responsible for EOAD. To study them further, we investigated a panel of candidate genes in 102 Italian EOAD patients, 45.10% of whom had a positive family history and 21.74% with a strong family history of dementia. We found that 10.78% of patients carried pathogenic or likely pathogenic variants, including a novel variant, in PSEN1, PSEN2, or APP, and 7.84% showed homozygosity for the ε4 APOE allele. Additionally, 7.84% of patients had a moderate risk allele in PSEN1, PSEN2, or TREM2 genes. Besides, we observed that 12.75% of our patients carried only a variant in genes associated with other neurodegenerative diseases. The combination of these variants contributes to explain 46% of cases with a definite familiarity and 32% of sporadic forms. Our results confirm the importance of extensive genetic screening in EOAD for clinical purposes, to select patients for future treatments and to contribute to the definition of overlapping pathogenic mechanisms between AD and other forms of dementia.

Family experience of young-onset dementia: the perspectives of spouses and children.

OBJECTIVES: Although young-onset dementia (YOD) affects the whole family system, this population is still under-represented in literature, and no progress in care provision has been made. Hence, additional evidence is necessary to understand how family and social relationships are affected by YOD and care challenges, as to provide recommendations for clinical practice and service improvement from a family perspective. METHOD: Family carers were recruited via one memory clinic and the local Alzheimer's Associations in Italy. Semi-structured interviews explored their experiences with YOD, the impact of the condition on their lives, family and social relationships, and the support and care they received. Transcripts were coded by three researchers and analysed using inductive thematic analysis. RESULTS: Thirty-eight interviews were conducted with 26 spouses and 12 adult children. Three themes emerged: 1) Problems around diagnosis, 2) Lack of post-diagnostic support, and 3) Living with YOD as a family. Overall, problems occurred across the dementia pathway. Without appropriate support, it was difficult for families to adjust to living with YOD and to the associated changes in family roles and relationships. CONCLUSIONS: Since optimal care depends on good family relationships, better support for families in the adaptation to condition would likely benefit patient care while ensuring social inclusion and health equity for vulnerable groups.

Viability of a MSQOL-54 general health-related quality of life score using bifactor model.

BACKGROUND: MSQOL-54 is a multidimensional, widely-used, health-related quality of life (HRQOL) instrument specific for multiple sclerosis (MS). Findings from the validation study suggested that the two MSQOL-54 composite scores are correlated. Given this correlation, it could be assumed that a unique total score of HRQOL may be calculated, with the advantage to provide key stakeholders with a single overall HRQOL score. We aimed to assess how well the bifactor model could account for the MSQOL-54 structure, in order to verify whether a total HRQOL score can be calculated. METHODS: A large international database (3669 MS patients) was used. By means of confirmatory factor analysis, we estimated a bifactor model in which every item loads onto both a general factor and a group factor. Fit of the bifactor model was compared to that of single and two second-order factor models by means of Akaike information and Bayesian information criteria reduction. Reliability of the total and subscale scores was evaluated with Mc Donald's coefficients (omega, and omega hierarchical). RESULTS: The bifactor model outperformed the two second-order factor models in all the statistics. All items loaded satisfactorily (≥ 0.40) on the general HRQOL factor, except the sexual function items. Omega coefficients for total score were very satisfactory (0.98 and 0.87). Omega hierarchical for subscales ranged between 0.22 to 0.57, except for the sexual function (0.70). CONCLUSIONS: The bifactor model is particularly useful when it is intended to acknowledge multidimensionality and at the same time take account of a single general construct, as the HRQOL related to MS. The total raw score can be used as an estimate of the general HRQOL latent score.

Assessing measurement invariance of MSQOL-54 across Italian and English versions.

PURPOSE: The Multiple Sclerosis Quality of Life-54 (MSQOL-54) is a specific multiple sclerosis (MS) health-related quality of life inventory consisting of 52 items organized into 12 subscales plus two single items. No study was found in literature assessing its measurement invariance across language versions. We investigated whether MSQOL-54 items provide unbiased measurements of underlying constructs across Italian and English versions. METHODS: Three constrained levels of measurement invariance were evaluated: configural invariance where equivalent numbers of factors/factor patterns were required; metric invariance where equivalent factor loadings were required; and scalar invariance where equivalent item intercepts between groups were required. Comparative fit index (CFI), root mean square error of approximation (RMSEA), and standardized root mean square residual (SRMR) fit indices and their changes between nested models were used to assess tenability of invariance constraints. RESULTS: Overall, the dataset included 3669 MS patients: 1605 (44%) Italian, mean age 41 years, 62% women, 69% with mild level of disability; 2064 (56%) English-speaking (840 [41%] from North America, 797 [39%] from Australasia, 427 [20%] from UK and Ireland), mean age 46 years, 83% women, 54% with mild level of disability. The configural invariance model showed acceptable fit (RMSEA = 0.052, CFI = 0.904, SRMR = 0.046); imposing loadings and intercepts equality constraints produced negligible worsening of fit (ΔRMSEA < 0.001, ΔCFI = - 0.002, ΔSRMR = 0.002 for metric invariance; ΔRMSEA = 0.003, ΔCFI = - 0.013, ΔSRMR = 0.003 for scalar invariance). CONCLUSIONS: These findings support measurement invariance of the MSQOL-54 across the two language versions, suggesting that the questionnaire has the same meaning and the same measurement paramaters in the Italian and English versions.

Characteristics of homicide perpetrators among Italian forensic hospital inmates.

OBJECTIVE: To identify distinctive clinical and social features of the psychiatric patients who committed homicide among inmates of Italian forensic hospitals. METHOD: Clinical and social characteristics of four cohorts of patients were compared: 64 inmates who committed or attempted homicide (Hs), their 64 matched controls from community services caseloads, 54 inmates who committed other crimes and their 54 matched controls from community services caseload. RESULTS: When compared with other inmates, patients who committed or attempted homicide showed less severe psychopathology (later onset of mental disorders, later contact with mental health services, lower disability scores) except for higher scores at BPRS "hostility" and "suspiciousness" factors; they also showed better premorbid adjustment (socioeconomic status, employment), and surprisingly better behavioural profile (fewer compulsory admissions, fewer previous criminal records, less substance abuse, less frequently in caseloads of community services). When compared with their matched controls, Hs had lower psychopathology, better adjustment, and a similar behavioural profile. CONCLUSIONS: Italian inmates of forensic hospitals who committed or attempted homicide have clinical features and personal histories which are far from the stereotype of the violent and dangerous psychiatric patients. The risk assessment procedures routinely performed in several countries may detect violent, but not homicidal behaviour.