Diego Giunta

The epidemiology of multiple sclerosis in Latin America and the Caribbean: a systematic review

The incidence and prevalence of multiple sclerosis (MS) varies geographically as shown through extensive epidemiological studies performed mainly in developed countries. Nonetheless, scant data is available in Latin America and the Caribbean (LAC). The objective of this review is to assess epidemiological data of MS in LAC. We conducted a systematic review of published articles and gray literature from January 1995 to May 2011. Twenty-two studies met the inclusion criteria after full-text review. Incidence data were found in only three studies and ranged from 0.3 to 1.9 annual cases per 100,000 person-years. Prevalence was reported in 10 studies and ranged from 0.83 to 21.5 cases per 100,000 inhabitants. The most prevalent subtype of MS was the relapsing–remitting form (48% to 91% of the series). No data about mortality were found. This study showed low frequency for MS in LAC compared with North American and European countries. The role of environmental and genetic factors should be well studied, providing new insights about its etiology.

Factors associated with nonattendance at clinical medicine scheduled outpatient appointments in a university general hospital

Introduction Nonattendance at scheduled outpatient appointments for primary care is a major health care problem worldwide. Our aim was to estimate the prevalence of nonattendance at scheduled appointments for outpatients seeking primary care, to identify associated factors and build a model that predicts nonattendance at scheduled appointments. Methods A cohort study of adult patients, who had a scheduled outpatient appointment for primary care, was conducted between January 2010 and July 2011, at the Italian Hospital of Buenos Aires. We evaluated the history and characteristics of these patients, and their scheduling and attendance at appointments. Patients were divided into two groups: those who attended their scheduled appointments, and those who did not. We estimated the odds ratios (OR) and corresponding 95% confidence intervals (95% CI), and generated a predictive model for nonattendance, with logistic regression, using factors associated with lack of attendance, and those considered clinically relevant. Alternative models were compared using Akaike’s Information Criterion. A generation cohort and a validation cohort were assigned randomly. Results Of 113,716 appointments included in the study, 25,687 were missed (22.7%; 95% CI: 22.34%–22.83%). We found a statistically significant association between nonattendance and age (OR: 0.99; 95% CI: 0.99–0.99), number of issues in the personal health record (OR: 0.98; 95% CI: 0.98–0.99), time between the request for and date of appointment (OR: 1; 95% CI: 1–1), history of nonattendance (OR: 1.07; 95% CI: 1.07–1.07), appointment scheduled later than 4 pm (OR: 1.30; 95% CI: 1.24–1.35), and specific days of the week (OR: 1.00; 95% CI: 1.06–1.1). The predictive model for nonattendance included characteristics of the patient requesting the appointment, the appointment request, and the actual appointment date. The area under the receiver operating characteristic curve of the predictive model in the generation cohort was 0.892 (95% CI: 0.890–0.894). Conclusion Evidence related to patient characteristics, and the identification of appointments with a higher likelihood of nonattendance, should promote guided strategies to reduce the rate of nonattendance, as well as to future research on this topic. The use of predictive models could further guide management strategies to reduce the rate of nonattendance.

Incidence of multiple sclerosis in Buenos Aires: a 16-year health maintenance organization-based study

Objective:  The present study was undertaken to determine the incidence of MS in a health maintenance organization from Buenos Aires, the largest populated area in Argentina.

Incidence and prevalence of Parkinson’s disease in Buenos Aires City, Argentina

Background and purpose:  Epidemiologic studies of incidence and prevalence in Parkinson’s Disease (PD) show highly variable results. Despite the large number of studies performed worldwide during the last decades, little is known about its prevalence in South America and no incidence studies have been performed. The goal of this study is to assess the incidence and prevalence of PD in a health maintenance organization from Buenos Aires City, the capital city of Argentina.

Mild prolonged chronic hyponatremia and risk of hip fracture in the elderly.

BACKGROUND Hip fractures are among the most serious bone fractures in the elderly, producing significant morbidity and mortality. Several observational studies have found that mild hyponatremia can adversely affect bone, with fractures occurring as a potential complication. We examined if there is an independent association between prolonged chronic hyponatremia (>90 days duration) and risk of hip fracture in the elderly. METHODS We performed a retrospective cohort study in adults >60 years of age from a prepaid health maintenance organization who had two or more measurements of plasma sodium between 2005 and 2012. The incidence of hip fractures was assessed in a very restrictive population: subjects with prolonged chronic hyponatremia, defined as plasma sodium values <135 mmol/L, lasting >90 days. Multivariable Cox regression was performed to determine the hazard ratio (HR) for hip fracture risk associated with prolonged chronic hyponatremia after adjustment for the propensity to have hyponatremia, fracture risk factors and relevant baseline characteristics. RESULTS Among 31 527 eligible patients, only 228 (0.9%) had prolonged chronic hyponatremia. Mean plasma sodium was 132 ± 5 mmol/L in hyponatremic patients and 139 ± 3 mmol/L in normonatremic patients (P < 0.001). The absolute risk for hip fracture was 7/282 in patients with prolonged chronic hyponatremia and 411/313 299 in normonatremic patients. Hyponatremic patients had a substantially elevated rate of hip fracture [adjusted HR 4.52 (95% CI 2.14-9.6)], which was even higher in those with moderate hyponatremia (<130 mmol/L) [adjusted HR 7.61 (95% CI 2.8-20.5)]. CONCLUSION Mild prolonged chronic hyponatremia is independently associated with hip fracture risk in the elderly population, although the absolute risk is low. However, proof that correcting hyponatremia will result in a reduction of hip fractures is lacking.

Incidence and prevalence of clinically relevant pituitary adenomas: retrospective cohort study in a Health Management Organization in Buenos Aires, Argentina

Objectives The main purpose of this study was to estimate the incidence rate and prevalence of clinically relevant pituitary adenomas (PAs) within the Hospital Italiano Medical Care Program (HIMCP), a well-defined population of 150,000 members living in the urban and suburban area of the city of Buenos Aires. We defined clinically relevant PAs as those associated with endocrine dysfunction and/or mass effect. Subjects and methods A retrospective open cohort study was conducted, including all members of the HIMCP over 18 years old, with active memberships during the period of the study, from January 1st 2003, to January 1, 2014. The incidence rates (IRs) were standardized (SIR) to the World Health Organization (WHO) 2000 standard population and were expressed per 100,000 members/year. Prevalence was estimated at January 1, 2014, and was expressed per 100,000 persons. The clinical records have been electronically managed since 2001. All lab and imaging studies were done in-house. Results The overall SIR was 7.39/100,000/year (95% CI 4.47-10.31). Female patients had a specific IR significantly higher than male patients (5.85 vs.1.54) and represented 73% of the affected members. Regarding tumor size, 61.4% were microadenomas, and the mean age at diagnosis was 46.4 years. Prolactinomas had the highest SIR (5.41), followed by acromegaly (Acro) and non-functioning adenomas (NFAs) with overlapping 95% CIs (0.44-1.41 and 0.31-0.99, respectively). Microprolactinomas were more frequent in female (72.6%) (p < 0.01) and younger members (38 vs.60 years; p < 0.04). The overall prevalence rate was 97.76/100,000. Prolactinomas had the highest prevalence (56.29), followed by NFAs (21.48), Acro (14.07) and CD (5.93). Conclusion Our results demonstrate that clinically relevant PAs are more common than usually suspected, especially prolactinomas and growth-hormone secreting PAs. These data highlight the need to increase the awareness of PAs, thereby enabling early diagnosis and treatment.

Performance of the Wells score in patients with suspected pulmonary embolism during hospitalization: a delayed-type cross sectional study in a community hospital.

INTRODUCTION The role of the Wells score for patients who develop signs and symptoms of pulmonary embolism (PE) during hospitalization has not been sufficiently validated. The aim of this study is to evaluate the performance of the Wells score for inpatients with suspected PE and to evaluate the prevalence of pulmonary embolism. MATERIALS AND METHODS We conducted a cross sectional study nested in the prospective Institutional Registry of Thromboembolic Disease at Hospital Italiano de Buenos Aires from June 2006 to March 2011. We included patients who developed symptoms of pulmonary embolism during hospitalization. Patients were stratified based on the Wells score as PE likely (>4 points) or PE unlikely (≤4 points). The presence of pulmonary embolism was defined by pre-specified criteria. RESULTS Six hundred and thirteen patients met the inclusion criteria, with an overall prevalence of PE of 36%. Two hundred and nineteen (34%) were classified as PE likely and 394 (66%) as PE unlikely with a prevalence of PE of 66% and 20%, respectively. The Wells score showed a sensitivity of 65 (95% CI 59-72), specificity 81 (95% CI 77-85), positive predictive value 66 (95% CI 60-72) and negative predictive value 80 (95% CI 77-84). CONCLUSIONS The Wells Score is accurate to predict the probability of PE in hospitalized patients and this population had a higher prevalence of PE than other cohorts. However, the score is not sufficiently predictive to rule out a potentially fatal disorder.

Incidence and prevalence of amyotrophic lateral sclerosis in an HMO of Buenos Aires, Argentina

Abstract The incidence of amyotrophic lateral sclerosis (ALS) ranges from 1.7 to 2.3 per 100,000 persons worldwide. Few epidemiological studies have been published in Latin America. The aim of this study was to estimate the incidence and prevalence of ALS in an HMO (Health Maintenance Organization) of Buenos Aires, capital city of Argentina. The population studied was affiliates of the Italian Hospital Medical Care Program, whose distribution across age and gender strata is similar to the population of Buenos Aires. Cases were detected from 1 January 2003 to 31 December 2010. Incidence density (ID) and prevalence for ALS were estimated for the whole period and at 31 December 2010, respectively. During the seven-year study period, the crude ID estimated was 3.17 per 100,000 person-years (95% CI 2.24–4.48) and the age-adjusted ID for the Buenos Aires population was 2.23 per 100,000 person-years (95% CI 1.45–3.01). Point prevalence at 31 December 2010 was 8.86 per 100,000 persons (95% CI 4.05–13.68). Mean age at diagnosis was 72.29 years (SD 8.5). In conclusion, estimated age-adjusted ID and prevalence of ALS were similar to the incidence and prevalence rates found in other geographical areas.

Comparative clinical study of locking screws versus smooth locking pegs in volar plating of distal radius fractures

The present study was performed to test the null hypothesis on no difference in stability of fixation after volar plating of intra-articular distal radius fractures (AO C2-C3) with either locking smooth pegs or locking screws in a clinical setting. A retrospective evaluation included adult patients with C2-C3 AO fractures treated with a volar plate with locking smooth pegs or locking screws. Radiographic assessment was performed to evaluate extra- and intra-articular parameters in the early postoperative period and after bone union. Twenty-seven consecutive patients were included. Thirteen cases had fixation with locking screws and 14 had fixation with locking smooth pegs. Both groups had bone fragment displacement after fixation. However, there were no significant differences between the groups either in extra- or intra-articular parameters defined by Kreder et al. (1996). Our study shows that, in a clinical setting, there is no difference in stability fixation between locking screws or smooth locking pegs in C2-C3 distal radius fractures.

Predictive value of non-invasive hemodynamic measurement by means of impedance cardiography in hypertensive subjects older than 50 years of age

Abstract The prognostic value of impedance cardiography (ICG; cardiac index [CI] and systemic vascular resistance index [SVRI] were measured) was assessed in this retrospective cohort study. A total of 1151 hypertensive outpatients >50 years with a baseline ICG were included. After median follow-up of 3.9 years, for the composite endpoint of cardiovascular events and stroke, adjusted HR for each 500 ml/min/m2 CI increase was 0.85 (CI95% 0.73–0.9, p = 0.039), and for each 500 dynes s cm−5 SVRI increase was 1.11 (CI95% 1.01–1.23, p = 0.046), whereas adjusted HR for all-cause mortality was not significant. ICG adds prognostic value to conventional risk factors in hypertensive patients.