BackgroundAlthough several face-to-face programs are dedicated to informal caregivers of persons with dementia, they are not always accessible to overburdened or isolated caregivers. Based on a face-to-face intervention program, we adapted and designed a Web-based fully automated psychoeducational program (called Diapason) inspired by a cognitive approach.ObjectiveThis study aimed to evaluate through a pilot unblinded randomized controlled trial the efficacy and acceptability of a Web-based psychoeducational program for informal caregivers of persons with Alzheimer’s disease (PWAD) based on a mixed methods research design.MethodsWe recruited and randomized offline 49 informal caregivers of a PWAD in a day care center in Paris, France. They either received the Web-based intervention and usual care for 3 months (experimental group, n=25) or only usual care (control group, n=24). Caregivers’ perceived stress (PSS-14, primary outcome), self-efficacy, burden, perceived health status, and depression (secondary outcomes) were measured during 3 face-to-face on-site visits: at baseline, at the end of the program (month 3), and after follow-up (month 6). Additionally, semistructured interviews were conducted with experimental group caregivers at month 6 and examined with thematic analysis.ResultsIntention-to-treat analysis did not show significant differences in self-perceived stress between the experimental and control groups (P=.98). The experimental group significantly improved their knowledge of the illness (d=.79, P=.008) from baseline to month 3. Of the 25 participants allocated to the experimental group, 17 (71%) finished the protocol and entirely viewed at least 10 of 12 online sessions. On average, participants used the website 19.72 times (SD 12.88) and were connected for 262.20 minutes (SD 270.74). The results of the satisfaction questionnaire showed that most participants considered the program to be useful (95%, 19/20), clear (100%, 20/20), and comprehensive (85%, 17/20). Significant correlations were found between relationship and caregivers’ program opinion (P=.01). Thus, positive opinions were provided by husbands and sons (3/3), whereas qualified opinions were primarily reported by daughters (8/11). Female spouses expressed negative (2/3) or neutral opinions (1/3). Caregivers expected more dynamic content and further interaction with staff and peers.ConclusionsIn this study, quantitative results were inconclusive owing to small sample size. Qualitative results indicated/showed little acceptance of the program and high expectations from caregivers. Caregivers did not rule out their interest in this kind of intervention provided that it met their needs. More dynamic, personalized, and social interventions are desirable. Our recruitment issues pointed out the necessity of in-depth studies about caregivers’ help-seeking behaviors and readiness factors.Trial RegistrationClinicaltrials.gov NCT01430286; http://clinicaltrials.gov/ct2/show/NCT01430286 (Archived by WebCite at http://www.webcitation/6KxHaRspL).

To cite this version:Alexandra Rouquette, Bruno Falissard. Sample size requirements for the internal validation of psychiatric scales.. International Journal of Methods in Psychiatric Research, Wiley, 2011, 20 (4) Abstract:The ratio of subjects to variables (N/p), as a rule to calculate the sample size required in internal validity studies on measurement scales, has been recommended without any strict theoretical or empirical basis being provided. The purpose of the present study was to develop a tool to determine sample size for these studies in the field of psychiatry. First, a literature review was carried out to identify the distinctive features of psychiatric scales. Then, two simulation methods were developed to generate data according to: 1/ the model for factor structure derived from the literature review and 2/ a real dataset. This enabled the study of the quality of solutions obtained from principal component analysis or Exploratory Factor Analysis (EFA) on various sample sizes. Lastly, the influence of sample size on the precision of Cronbach"s alpha coefficient was examined. The N/p ratio rule is not upheld by this study: short scales do not allow smaller sample size. As a rule of thumb, if one"s aim is to reveal the factor structure, a minimum of 300 subjects is generally acceptable but should be increased when the number of factors within the scale is large, when EFA is used and when the number of items is small.

Several groups have published flow cytometry scores useful for the diagnosis or prognosis of myelodysplastic syndromes (MDS), mainly based on the detection of immunophenotypic abnormalities in the maturation of granulocytic/monocytic and lymphoid lineages. As anemia is the most frequent symptom of early MDS, the aim of this study was to identify markers of dyserythropoiesis relevant for the diagnosis of MDS analyzed by selecting erythroblasts in a whole no-lysis bone marrow strategy by using a nuclear dye. This prospective study included 163 patients, including 126 with cytopenias leading to MDS suspicion and 46 controls without MDS. In a learning cohort of 53 unequivocal MDS with specific markers, there was a significant difference between the coefficients of variation of mean fluorescence intensities of CD71 and CD36 in MDS patients compared with controls. These two parameters and the hemoglobin level were used to build a RED-score strongly suggestive of MDS if ≥ 3. Using the RED-score in the whole cohort, 80% of MDS or non-MDS patients were correctly classified. When combined with the flow score described by Ogata et al., this strategy allowed to reach a very high sensitivity of 88% of patients correctly classified.