Polypharmacy among older Brazilians: prevalence, factors associated, and sociodemographic disparities (ELSI-Brazil)

Background:

Polypharmacy has become an increasingly public health issue as population age and novel drugs are developed. Yet, evidence on low- and middle-income countries (LMIC) is still scarce.

Objective:

This work aims to estimate the prevalence of polypharmacy among Brazilians aged 50 and over, and investigate associated factors.

Methods:

A cross-sectional study was conducted using data from the baseline assessment of the Brazilian Longitudinal Study of Aging (ELSI-Brazil), a nationally representative study of persons aged 50 years and older (n=9,412). Univariate and bivariate analyses described the sample. Robust Poisson regression was used to estimate prevalence ratios and predict probabilities of polypharmacy.

Results:

Prevalence of polypharmacy was estimated at 13.5% among older adults in Brazil. Important disparities were observed in regard to gender (16.1% among women and 10.5% among men), race (16.0% among whites and 10.1% among blacks) and geographic region (ranging from 5.1% in the North to 18.7% in the South). The multivariate analysis showed that polypharmacy is associated with various sociodemographic/individual factors (age, gender, race, education, region, health status, body mass index) as well as with several variables of healthcare access/utilization (number of visits, same physician, provider’s knowledge of patient’s medications, gate-keeper, and difficulty managing own medication). Overall, the more utilization of health services, the higher the probability of polypharmacy, after adjusting for all other model covariates.

Conclusions:

Polypharmacy prevalence is relatively low in Brazil, compared to European countries. After controlling for variables of healthcare need and demographic characteristics, there is still substantial residual variance in polypharmacy prevalence. Policies to identify inappropriate prescribing and reduce regional discrepancies are necessary.

Abstract 5: CT Perfusion is Not a Treatment Effect Modifier for Mechanical Thrombectomy in the 0-8-Hour-Window: A Pre-Planned Analysis of the RESILIENT Trial

Background: CT perfusion has been increasingly used as a selection tool in acute reperfusion therapies. However, it remains unknown whether its use is associated with a higher treatment benefit in patients undergoing thrombectomy. We sought to evaluate the interaction between imaging selection modalities and treatment effect in the RESILIENT Trial.

Methods: RESILIENT was a randomized, prospective, multicenter, controlled trial evaluating the safety, efficacy, and cost-effectiveness of thrombectomy versus medical treatment alone in Brazil. A total of 221 patient were enrolled. The trial showed a strong benefit of thrombectomy (90-day mRS ordinal shift, OR 2.28 95%CI [1.41-3.70]; p=0.001). Key imaging selection criteria included ASPECTS ≥6 on non-contrast CT (NCCT) and the exclusion of malignant collateral profile on CT angiography. The use of automated CT perfusion software (RAPID, IschemaView) was optional but was made available in some centers with the pre-specified plan to compare imaging selection modalities. The primary end-point was the common odds ratio (cOR) of mRs at 90 days (shift analysis) and the main secondary endpoint was the rate of functional independence (mRS 0-2) at 90 days. Ordinal logistic and binary regression analyses with imaging selection modality (NCCT versus CTP) as an interaction term were performed with adjustments for potential confounders including age, baseline NIHSS score, occlusion site, IV tPA use and ASPECTS. A p value < 0.05 was considered statistically significant.

Results: CTP was performed in 41% of the thrombectomy group and 45% in the control group. There was no significant difference in the treatment effect size for patients selected on the basis of NCCT and CTA only versus those submitted to CTP in terms of overall functional disability (ordinal mRS shift: aOR: 2.87, 95%CI [1.47-5.61] vs. 2.10, 95%CI [1.01-4.36]; p=0.390) or functional independence (mRS 0-2: aOR: 3.16, 95%CI [1.32-7.57] vs. 2.54 95%CI [0.86-7.49], p=0.40) at 90 days.

Conclusion: In a randomized clinical trial of thrombectomy within 8 hours of stroke onset, there was no evidence of difference in the treatment effect size across patients selected with NCCT and CTA alone versus automated CT perfusion software.

Postural Muscle Unit Plasticity in Stroke Survivors: Altered Distribution of Gastrocnemius' Action Potentials

Neuromuscular adaptations are well-reported in stroke survivors. The death of motor neurons and the reinnervation of residual muscle fibers by surviving motor neurons, for example, seem to explain the increased density of muscle units after stroke. It is, however, unknown whether reinnervation takes place locally or extensively within the muscle. Here we combine intramuscular and surface electromyograms (EMGs) to address this issue for medial gastrocnemius (MG); a key postural muscle. While seven stroke survivors stood upright, two intramuscular and 15 surface EMGs were recorded from the paretic and non-paretic gastrocnemius. Surface EMGs were triggered with the firing instants of motor units identified through the decomposition of both intramuscular and surface EMGs. The standard deviation of Gaussian curves fitting the root mean square amplitude distribution of surface potentials was considered to assess differences in the spatial distribution of motor unit action potentials and, thus, in the distribution of muscle units between limbs. The median number of motor units identified per subject in the paretic and non-paretic sides was, respectively, 2 (range: 1–3) and 3 (1–4). Action potentials in the paretic gastrocnemius were represented at a 33% wider skin region when compared to the non-paretic muscle (Mann-Whitney; P = 0.014). Side differences in the representation of motor unit were not associated with differences in subcutaneous thickness (skipped-Spearman r = −0.53; confidence interval for r: −1.00 to 0.63). Current results suggest stroke may lead to the enlargement of the gastrocnemius muscle units recruited during standing. The enlargement of muscle units, as assessed from the skin surface, may constitute a new marker of neuromuscular plasticity following stroke.

Abstract TP230: The Development of a Stroke System of Care in Brazil: Where Are We Now?

Introduction: The organization of the stroke care in Brazil started in 2002 after the tPA approval. In 2008, was started a task force of stroke neurologists together with the Ministry of Health (MOH) with the objective of supporting the establishment of a nationwide network. Since then, the hospitals have progressively improved their structure. In 2012, was launched the National Stroke Policy, by the MOH, with creation of stroke centers in public health system, reimbursement of tPA, implementation of telemedicine and creation of the Line of Care integrating all stroke assistance. The aim of this study is to compare the structure of stroke care in 2008 and 2017.

Method: This cross-sectional study compared the structure of stroke centers in 2008 and 2017. The information was collected through online questionnaires sent to the stroke centers and to the vascular neurologists.

Results: In 2008, 35 stroke centers were active (40% assisting public health patients), only 14% with stroke units and no hospital had telemedicine. The National Emergency Medical Service (EMS) was trained in 4 cities, covering 23% of stroke centers. In 2017, there are 139 stroke centers registered in Brazil. We had answers from 110 hospitals (79%) in 15 out of 26 states (9 states do not have stroke centers). The EMS covers 96% of the stroke centers but only 63% is linked with the local network. The centers are 34% public, 42% private and 24% assist both public and private patients (58% assist public health system). The stroke units are present in 49% of hospitals. Neurologists are available 24h /7 days a week in 82% of the hospitals (33% on duty, 44% on call and 23% by telemedicine). In total, 41% of hospitals are comprehensive stroke centers. As the thrombectomy devices are not paid in the public hospitals, only 2 are comprehensive stroke centers, 8 had structure but not devices and are participating in a clinical trial to approve thrombectomy in public hospitals in Brazil.

Conclusion: The organization of stroke care in Brazil has improved a lot in recent years. Despite this, we have a lot to improve, since it’s still a small number of hospitals for a huge country, with large part of its population without access to the best treatments.