Biomedical subjects

Mounir Mesbah

Publications and source records attributed to Mounir Mesbah.

6 recordsLinked to original sources

PubMed2006

Prevalence of visual impairment in relation to the number of ophthalmologists in a given area: a nationwide approach.

BACKGROUND: Sociological and economic risk factors of visual impairment have never been described in France at a national level as the association between the number of ophthalmologists per inhabitant and visual impairment prevalence. METHODS: Two national surveys were pooled. First, 2075 institutions were selected at random from the French Health Ministry files. Second, a random, stratified sample of 356,208 citizens living in the community was selected. Blindness and low vision (LV) prevalence rates were estimated by age and gender. Geographical equities were estimated by logistic regression adjusted on age and occupational category. The association between ophthalmologist density and visual impairment prevalence rate was estimated per region. Interviews were completed with 14,603 (94.9%) of 15,403 randomly selected subjects in institutions, and 16,945 (77.8%) of 21,760 randomly selected subjects in the community. Three groups were defined from the interviews: low vision, blind, and control. RESULTS: Prevalence rates were LV 2.08% and blindness 0.12%. Both rates increased exponentially with age. No major difference was found with gender. Injury was the declared reason for both LV (12%) and blindness (12%). Large regional differences in prevalence persisted for LV after adjustment on age and occupation (ORs: 0.35 to 2.10), but not for blindness. Regions with ophthalmologists below the national per capita average were usually those with higher LV prevalence. CONCLUSION: An inverse correlation was found between ophthalmologist number and LV prevalence rates for subjects of similar age and socio-professional category. This denoted possible inequity in the provision of healthcare.

Activities of Daily Living↗

PubMed2006

Nonmedical economic consequences attributable to visual impairment: a nation-wide approach in France.

The nonmedical costs of visual impairment are crucial when allocating resources for prevention or treatment programs. Were analyzed the data from two representative nationwide French surveys aimed at documenting impairments that included 14,603 subjects living in institutions and 16,945 in the community. Three groups were identified: blind (light perception), low vision (loss of shape perception, LV), and controls. Item consumption was standardized on confounding factors using logistic regression. Costs attributable to visual impairment were estimated from control subjects. National nonmedical costs due to visual impairment were euro 9,806 million, arising mostly from LV (euro 8,735 million). The annual average cost/subject was euro 7,242 for LV and euro 15,679 for blindness. Loss of family income was euro 4,552 million, the burden on the caregiver euro 2,525 million, paid assistance euro 2,025 million, social allowances euro 0,942 million, and unmet needs euro 5,553 million. Resource allocation strategies aimed at controlling visual impairment should cover all relevant economic dimensions, including nonmedical items.

Activities of Daily Living↗

PubMed2005

Prevalence and burden of self-reported blindness and low vision for individuals living in institutions: a nationwide survey.

BACKGROUND: The prevalence of self-reported low vision (LV) and blindness, and their associated disabilities, handicaps and socio-economic consequences for individuals living in institutions are poorly documented. METHODS: 2,075 institutions were selected at random and eight individuals were picked at random from the list of residents. Three groups of individuals were defined: blind, LV, and a control group (CG). These were compared after adjustment for age and co-morbidities. Of the 15,403 individuals, 14,603 interviews (94.9%) were completed. RESULTS: The prevalence of blindness was 1.6% and the LV 13.4%. Blind individuals needed assistance more often (OR: 2.65 to 11.35) than CG members while the assistance required by LV individuals was similar to that for the CG. Blind individuals required institution adaptation (building and furniture changes) more often than the CG. Blind (57.9%) and LV individuals (35.4%) were more often registered for social allowances. Monthly social allowances were EUR 86 higher for blind than LV individuals. Monthly family incomes were found to be similar between the three groups (from EUR 782 to 797). Social and demographic data, institution description, income, handicaps, disabilities, social allowances and details of daily activities were collected interviews. CONCLUSION: The results demonstrate the impact of self-reported blindness and LV on daily life for patients living in institutions.

Activities of Daily Living↗

PubMed2005

Prevalence and burden of self-reported blindness, low vision, and visual impairment in the French community: a nationwide survey.

OBJECTIVE: To estimate the prevalence of self-reported visual impairment and its association with disabilities, handicaps, and socioeconomic consequences. METHODS: A national survey was conducted on a random stratified sample of 359 010 French citizens living in the community; 21 760 subjects were selected at random and 16 945 persons (78%) agreed to further questioning. Four thousand ninety-one randomly selected caregivers were interviewed. Four subgroups of subjects were defined (blind or light perception only, low vision or still have form perception, other visual problems, and no visual problems). These were compared after adjustment for age, comorbidity, and household size differences. RESULTS: The prevalence of blindness was 0.10% and of low vision, 1.94%. Subjects with blindness needed assistance with daily activities more often than subjects with no visual problems; they also needed more house modifications. Many subjects with blindness (46.8%) and subjects with low vision (29.0%) were registered for social allowances. Subjects with blindness had fewer paid activities (4.5%) than subjects with no visual problems (20.7%). Social allowances increased considerably (by 277) between those with low vision and those with blindness. Monthly household incomes were lower (P<.001) for subjects with low vision (1255) and blindness (1587) than for subjects with no visual problems (1851). MAIN OUTCOME MEASURES: Collected data included social demography, home description, household income, handicaps, disabilities, social allowances, and daily activities. CONCLUSION: The results demonstrate associations between self-reported visual impairment and daily living.

Activities of Daily Living↗

PubMed2005

Scoring of visual field measured through Humphrey perimetry: principal component varimax rotation followed by validated cluster analysis.

PURPOSE: To extract unidimensional, well-separated latent scores that are anatomically and clinically valid from 52 standardized variables collected by Humphrey visual field (VF) perimetry (Carl Zeiss Meditec, Dublin, CA). METHODS: Visual field data of 437 patients were collected and classified by a glaucoma specialist into seven clinical groups: irregularities of VF (IVF), nasal step (NaS), arcuate scotoma (AC), paracentral scotoma (PCS), blind-spot enlargement (BSE), diffuse deficit (DD), and advanced deficit (AD). The number and content of constituent variable scores were identified by principal components analysis followed by Varimax Rotation and simple clustering, taking spatial distribution homogeneity and visual system anatomy into account. Unidimensionality was checked by a stepwise Cronbach alpha curve. Clinical predictability of the derived scores was checked by comparing clinical groups (ANOVA). RESULTS: Patients older than 60 years comprised 53.3% of the sample. The average mean deviation was -9.2 dB and pattern standard deviation was 6.5 dB. Six scores were identified: four peripheral scores (nasal superior, NS; nasal inferior, NI; temporal superior, TS; and temporal inferior, TI) and two paracentral scores (PCSs; superior, PCSS; and inferior, PCSI). Cronbach alpha was always >0.90. The six scores decreased sequentially from IVF to DD to AD. Scores of AC were lower in NS, NI, and TS; PCSS was less in PCS; BSE scores were less in TS and TI; NaS scores were less in NS and NI. CONCLUSIONS: Six well-separated, optimal scores were obtained from the Humphrey perimetry matrix. Internal reliability was good. It was possible to discriminate between clinical subgroups. Further analyses, based on longitudinal data, must be performed to confirm these findings.

Cluster Analysis↗

PubMed2002

Joint modeling of event time and nonignorable missing longitudinal data.

Survival studies usually collect on each participant, both duration until some terminal event and repeated measures of a time-dependent covariate. Such a covariate is referred to as an internal time-dependent covariate. Usually, some subjects drop out of the study before occurrence of the terminal event of interest. One may then wish to evaluate the relationship between time to dropout and the internal covariate. The Cox model is a standard framework for that purpose. Here, we address this problem in situations where the value of the covariate at dropout is unobserved. We suggest a joint model which combines a first-order Markov model for the longitudinally measured covariate with a time-dependent Cox model for the dropout process. We consider maximum likelihood estimation in this model and show how estimation can be carried out via the EM-algorithm. We state that the suggested joint model may have applications in the context of longitudinal data with nonignorable dropout. Indeed, it can be viewed as generalizing Diggle and Kenward's model (1994) to situations where dropout may occur at any point in time and may be censored. Hence we apply both models and compare their results on a data set concerning longitudinal measurements among patients in a cancer clinical trial.

Algorithms↗