Aims: To summarize evidence on the frequency and predictors of health‐care utilization among people who use illicit drugs.Design: Systematic search of MEDLINE, EMBASE and PsychINFO for observational studies reporting health‐care utilization published between 1 January 2000 and 3 December 2018. We conducted narrative synthesis and meta‐analysis following a registered protocol (identifier: CRD42017076525).Setting and participants: People who use heroin, powder cocaine, crack cocaine, methamphetamine, amphetamine, ecstasy/3,4‐methyl​enedioxy​methamphetamine (MDMA), cannabis, hallucinogens or novel psychoactive substances; have a diagnosis of ‘substance use disorder’; or use drug treatment services.Measurements: Primary outcomes were the cumulative incidence (risk) and rate of care episodes in three settings: primary care, hospital admissions (in‐patient) and emergency department (ED).Findings: Ninety‐two studies were included, 84% from North America and Australia. Most studies focused on people using heroin, methamphetamine or crack cocaine, or who had a diagnosis of drug dependence. We were able to conduct a meta‐analysis of rates across 25 studies reporting ED episodes and 25 reporting hospital admissions, finding pooled rates of 151 [95% confidence interval (CI) = 114–201] and 41 (95% CI = 30–57) per 100 person‐years, respectively; on average 4.8 and 7.1 times more often than the general population. Heterogeneity was very high and was not explained by drugs used, country of study, recruitment setting or demographic characteristics. Predictors of health‐care utilization were consistent across studies and included unstable housing, drug injection and mental health problems. Opioid substitution therapy was consistently associated with reduced ED presentation and hospital admission. There was minimal research on health‐care utilization by people using ecstasy/MDMA, powder cocaine, hallucinogens or novel psychoactive substances.Conclusions: People who use illicit drugs are admitted to emergency department or hospital several times more often than the general population.

Objective To determine the rate and appropriateness of antibiotic prescribing for acutely ill children in ambulatory care in high-income countries. Design On 10 February 2021, we systematically searched articles published since 2000 in MEDLINE, Embase, CENTRAL, Web Of Science and grey literature databases. We included cross-sectional and longitudinal studies, time-series analyses, randomised controlled trials and non-randomised studies of interventions with acutely ill children up to and including 12 years of age in ambulatory care settings in high-income countries. Pooled antibiotic prescribing and appropriateness rates were calculated using random-effects models. Meta-regression was performed to describe the relationship between the antibiotic prescribing rate and study-level covariates. Results We included 86 studies comprising 11 114 863 children. We found a pooled antibiotic prescribing rate of 45.4% (95% CI 38.2% to 52.8%) for all acutely ill children, and 85.6% (95% CI 73.3% to 92.9%) for acute otitis media, 37.4% (95% CI 30.9% to 44.3%) for respiratory tract infections, and 40.4% (95% CI 29.9% to 51.9%) for other diagnoses. Considerable heterogeneity can only partly be explained by differences in diagnoses. The overall pooled appropriateness rate is 68.5% (95% CI 55.8% to 78.9%, I²=99.8%; 19 studies, 119 995 participants). 38.3% of all prescribed antibiotics were aminopenicillins. Conclusions Antibiotic prescribing rates for acutely ill children in ambulatory care in high-income countries remain high. Large differences in prescription rates between studies can only partly be explained by differences in diagnoses. Better registration and further research are needed to investigate patient-level data on diagnosis and appropriateness.

Sutherland, Angus, Joseph Freer, Laura Evans, Alberto Dolci, Matteo Crotti, and Jamie Hugo Macdonald. MEDEX 2015: Heart rate variability predicts development of acute mountain sickness. High Alt Med Biol 00:000–000, 2017. Aims: Acute mountain sickness (AMS) develops when the body fails to acclimatize to atmospheric changes at altitude. Preascent prediction of susceptibility to AMS would be a useful tool to prevent subsequent harm. Changes to peripheral oxygen saturation (SpO₂) on hypoxic exposure have previously been shown to be of poor predictive value. Heart rate variability (HRV) has shown promise in the early prediction of AMS, but its use pre-expedition has not previously been investigated. We aimed to determine whether pre- and intraexpedition HRV assessment could predict susceptibility to AMS at high altitude with better diagnostic accuracy than SpO₂. Methods: Forty-four healthy volunteers undertook an expedition in the Nepali Himalaya to >5000 m. SpO₂ and HRV parameters were recorded at rest in normoxia and in a normobaric hypoxic chamber before the expedition. On the expedition HRV parameters and SpO₂ were collected again at 3841 m. A daily Lake Louise Score was obtained to assess AMS symptomology. Results: Low frequency/high frequency (LF/HF) ratio in normoxia (cutpoint ≤2.28 a.u.) and LF following 15 minutes of exposure to normobaric hypoxia had moderate (area under the curve ≥0.8) diagnostic accuracy. LF/HF ratio in normoxia had the highest sensitivity (85%) and specificity (88%) for predicting AMS on subsequent ascent to altitude. In contrast, pre-expedition SpO₂ measurements had poor (area under the curve <0.7) diagnostic accuracy and inferior sensitivity and specificity. Conclusions: Pre-ascent measurement of HRV in normoxia was found to be of better diagnostic accuracy for AMS prediction than all measures of HRV in hypoxia, and better than peripheral oxygen saturation monitoring.

Achieving universal health coverage by 2030 requires that lessons from the Millennium Development Goals must be heeded. The most important lesson is that the workforce underpins every function of the health system, and is the rate-limiting step. The three dimensions that continue to limit the success of the development agenda are availability, distribution and performance of health workers – and the Sustainable Development Goals cannot be achieved without addressing all three. Hence, the traditional response of scaling up supply is inadequate: a paradigm shift is required in the design of systems that can properly identify, train, allocate and retain health workers.