Maria Jose Bravo

Introduction: In this study we aimed to determine the maximal isometric muscle strength of a healthy, normal‐weight, pediatric population between 6 and 15 years of age using hand‐held dynamometry to establish strength reference values. The secondary objective was determining the relationship between strength and anthropometric parameters. Methods: Four hundred normal‐weight Chilean children, split into 10 age groups, separated by 1‐year intervals, were evaluated. Each age group included between 35 and 55 children. Results: The strength values increased with increasing age and weight, with a correlation of 0.83 for age and 0.82 for weight. The results were similar to those reported in previous studies regarding the relationships among strength, age, and anthropometric parameters, but the reported strength differed. Conclusions: These results provide normal strength parameters for healthy and normal‐weight Chilean children between 6 and 15 years of age and highlight the relevance of ethnicity in defining reference values for muscle strength in a pediatric population. Muscle Nerve 55: 16–22, 2017

Aims: A systematic review and meta‐analysis were conducted to synthesize results from cohort studies on initiation into drug injection among vulnerable populations, to quantify heterogeneity in the estimated incidence rates of drug injection and to identify potential sources of heterogeneity and bias.Methods: MEDLINE, EMBASE, PsycINFO and LILACS were searched for relevant studies published between 1980 and 2012. Investigators independently reviewed studies for inclusion, retrieved information on baseline population characteristics and follow‐up features and assessed study quality. Study‐specific incidence rates of drug injection were calculated as the number of new injectors divided by the person‐years at risk. The I² statistic was used to quantify heterogeneity in incidence rates across studies, and random‐effects meta‐regression models were used to identify determinants of heterogeneity and bias.Results: Nine cohorts totalling 1843 participants met the inclusion criteria, with individual sample sizes of 70–415 participants and follow‐up lengths of 6 months–3.4 years. The incidence of drug injection varied widely, from 2.1 to 24.2 cases per 100 person‐years. The strong between‐study heterogeneity (I² = 90%, PI² = 17%, P = 0.30), with a 57% (95% confidence interval 46–66%) decrease in the pooled incidence of drug injection per 1‐year increase in average follow‐up.Conclusions: The incidence of drug injection decreases sharply with increasing follow‐up length in cohort studies on drug injection initiation. Low retention rates and potential for downward selection bias in cohort studies on drug injection initiation are caused primarily by greater loss to follow‐up among individuals at higher risk of starting injection, compared with other participants.

Background/Aims: Non-fatal opioid overdose (NFOO) and major depression (MD) are highly prevalent in heroin users. Many risk factors are known for NFOO, but studies in non-clinical samples on its relationship with MD are lacking. We aimed to examine this relationship in a street-recruited sample, controlling for potential well-known confounders. Methods: A cross-sectional study in 452 heroin users street-recruited by chain referral methods in three Spanish cities. Eligibility criteria were: age ≤30 years, heroin use at least 12 days in the last year and at least once in the last 3 months. Depression was assessed using the Composite International Diagnostic Interview. A precise definition of NFOO was used. Adjusted odds ratios (AORs) for the NFOO predictors were obtained by logistic regression. Results: The prevalence of NFOO and MD in the last 12 months was 9.1 and 23.2%, respectively. After adjusting for potential confounders, NFOO and MD were significantly associated (AOR 2.2; 95% CI 1.01-4.74). Other associated factors were imprisonment (AOR 4.1; 95% CI 1.4-12.1), drug injection (AOR 6.7; 95% CI 2.4-18.4) and regular use of tranquillisers/sleeping pills (AOR 2.9; 95% CI 1.16-7). Conclusions: Drug and mental health treatment facilities should consider the relationship between MD and NFOO when contacting and treating heroin users. Imprisonment, drug injection and use of tranquillisers/sleeping pills are also risk factors for NFOO.