Jesús de Pedro Cuesta

Global versus factor-related impression of severity in Parkinson's disease : A new clinimetric index (CISI-PD)

In Parkinsons disease (PD), the Clinical Global Impression of Severity (CGIS) is often used as an additional outcome in clinical trials. It is hypothesized that this measure summarizes clinical assessment and is mainly influenced by the rating of four domains, namely, motor signs, disability, motor complications, and cognitive impairment. Ratings of these four factors were combined to form a new Clinical Impression of Severity Index for Parkinsons Disease (CISI‐PD). A sample of 150 PD patients was evaluated using the following scales: Hoehn and Yahr staging, Schwab and England scale, Unified Parkinsons Disease Rating Scale, Scales for Outcomes in Parkinsons Disease–Motor Scale, CGIS, and CISI‐PD. The results show that the CGIS is closely related to the above‐mentioned measures (r = 0.49–0.89). CISI‐PD correlation with these scales was very similar (r = 0.55–0.91), to the extent that the difference between corresponding coefficients was systematically less than 0.10. A multiple regression model showed that 92% of the CIGS variance was explained by the four CISI‐PD items. Finally, the CISI‐PD displayed adequate psychometric properties, with satisfactory internal consistency (α = 0.90) and convergent (r > 0.75) and known‐groups validity. The CISI‐PD is a valid and reliable measure that expands the information obtained via the CGIS.

Burden of disease related to Parkinson's disease in Spain in the year 2000

We measured the burden caused by Parkinsons disease (PD) in Spain during the year 2000 and compared it against PD burden worldwide and in the European A subregion. Burden of disease (BoD) is an important factor in health policy. Disability‐adjusted life years (DALY) as a measure of BoD is the result of adding years of life lost (YLL) and years lived with disability (YLD). The burden of PD (BPD) has not been studied in Spain. YLL were obtained from the Spanish death certificates and YLD from the estimated number of incident PD cases and the average PD duration. PD disability was calculated, using the Disability Weights for Diseases in the Netherlands. Prior PD DALY data for Europe and the world were obtained from the 2001 World Health Organization World Health Report. A discount rate of 3% and age‐weighting modulation factor with K = 1 were used. In Spain, PD generated 67,582 DALY, comprising 6,351 (9.4%) YLL and 61,231 (90.6%) YLD. Most PD DALY (57.5%) occurred in the population 60 to 74 years of age. When PD DALY estimates were adjusted using the world population in 2000, Spain registered a PD DALY rate of 84 per 100,000 population, higher than both the world and European A subregion rates (24 and 35 per 100,000 population, respectively). PD burden in Spain in 2000 was high, with disability being the major contributing factor. Although BPD in Spain was greater than both world and European A subregion BPD, these differences should nevertheless be interpreted with caution.

Validation of the Functional Independence Scale

OBJECTIVE To assess the psychometric quality of an instrument designed to measure functional independence (Functional Independence Scale [FIS]) in several activities of daily living domains and to be applied by trained non-health-related interviewers. The study was carried out in the autonomous region of Madrid in community-dwelling elders. METHODS We performed a cross-sectional validation study. In addition to the FIS, Pfeiffers questionnaire, the Depression Subscale of the Hospital Anxiety and Depression Scale, the Comorbidity Index, the Barthel Index, and EQ-5D were used. These measures were cross-sectionally applied to community-dwelling elders (n=500) and outpatients in a general hospital (n=100) aged 65 years. The following FIS psychometric attributes were analyzed: acceptability, scaling assumptions, internal consistency, construct validity, and precision. RESULTS A fully computable FIS total score was obtained in 94.3% of the subjects. A ceiling effect (60.65%), but no floor effect (0.22%) was evident in the community-dwelling elders. No floor or ceiling effects were detected in the hospital sample. Scaling assumptions and internal consistency were satisfactory (item-total correlations: 0.57-0.91; Cronbachs alpha: 0.94). Factor analysis identified three factors that explained 74.3% of the variance. Indexes of convergent, internal, and known-groups validity were satisfactory. The scales precision, determined by the standard error of measurement (2.49; 95%CI=4.88), was also satisfactory. CONCLUSION The FIS is an easy-to-use instrument with appropriate metric attributes. This scale can be usefully applied in broad samples of non-institutionalized elders by non-health related personnel.

Sensitivity to Biases of Case-Control Studies on Medical Procedures, Particularly Surgery and Blood Transfusion, and Risk of Creutzfeldt-Jakob Disease

Background: Evidence of risk of Creutzfeldt-Jakob disease (CJD) associated with medical procedures, including surgery and blood transfusion, is limited by susceptibility to bias in epidemiological studies. Methods: Sensitivity to bias was explored using a central-birth-cohort model using data from 18 case-control studies obtained after a review of 494 reports on medical procedures and risk of CJD, systematic for the period January 1, 1989 to December 31, 2011. Results: The validity of the findings in these studies may have been undermined by: recall; control selection; exposure assessment in life-time periods of different duration, out of time-at-risk of effect, or asymmetry in case/control data; and confounding by concomitant blood transfusion at the time of surgery. For sporadic CJD (sCJD), a history of surgery or blood transfusion was associated with risk in some, but not all, recent studies at a ≥10 year lag time, when controls were longitudinally sampled. Space-time aggregation of surgical events was not seen. Surgery at early clinical onset might be overrepresented among cases. Neither surgical history nor blood transfusion unlabelled for donor status, dental treatments or endoscopic examinations were linked to variant CJD (vCJD). Conclusions: These results indicate the need for further research. Common challenges within these studies include access to and content of past medical/dental treatment records for diseases with long incubation periods.