Vast empirical evidence underscores that exporting firms are more productive than non-exporters. As governments accordingly pursue export-promoting policies we are interested in the firmness of these conclusions with respect to African small and medium sized enterprises (SMEs) and the influence of the destination of export trade. Using a micro-panel dataset from five African countries we confirm the self-selection. We apply propensity scores to match exporters and use a difference-in-difference methodology to test if African SMEs experience productivity gains because of export participation. Results indicate that African firms significantly learn-by-exporting. Manufacturers obtain significant performance improvements due to internationalization although this effect is moderated by export destination. Firms that export outside Africa become more capital intensive and at the same time hire more workers. In contrast we find evidence that exporters within the African region significantly downsize in capital intensity. Results regarding skill-bias of internationally active firms are mixed, where exporters within the region expand in size and hire more relatively unskilled workers.
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We describe the incidence, practice and associations with outcomes of awake prone positioning in patients with acute hypoxemic respiratory failure due to coronavirus disease 2019 (COVID-19) in a national multicenter observational cohort study performed in 16 intensive care units in the Netherlands (PRoAcT−COVID-study). Patients were categorized in two groups, based on received treatment of awake prone positioning. The primary endpoint was practice of prone positioning. Secondary endpoint was ‘treatment failure’, a composite of intubation for invasive ventilation and death before day 28. We used propensity matching to control for observed confounding factors. In 546 patients, awake prone positioning was used in 88 (16.1%) patients. Prone positioning started within median 1 (0 to 2) days after ICU admission, sessions summed up to median 12.0 (8.4−14.5) hours for median 1.0 day. In the unmatched analysis (HR, 1.80 (1.41−2.31); p < 0.001), but not in the matched analysis (HR, 1.17 (0.87−1.59); p = 0.30), treatment failure occurred more often in patients that received prone positioning. The findings of this study are that awake prone positioning was used in one in six COVID-19 patients. Prone positioning started early, and sessions lasted long but were often discontinued because of need for intubation.
The aim of this analysis was to compare ventilation management and outcomes in invasively ventilated patients with acute hypoxemic respiratory failure due to coronavirus disease 2019 (COVID-19) between the first and second wave in the Netherlands. This is a post hoc analysis of two nationwide observational COVID-19 studies conducted in quick succession. The primary endpoint was ventilation management. Secondary endpoints were tracheostomy use, duration of ventilation, intensive care unit (ICU) and hospital length of stay (LOS), and mortality. We used propensity score matching to control for observed confounding factors. This analysis included 1122 patients from the first and 568 patients from the second wave. Patients in the second wave were sicker, had more comorbidities, and had worse oxygenation parameters. They were ventilated with lower positive end-expiratory pressure and higher fraction inspired oxygen, had a lower oxygen saturation, received neuromuscular blockade more often, and were less often tracheostomized. Duration of ventilation was shorter, but mortality rates were similar. After matching, the fraction of inspired oxygen was lower in the second wave. In patients with acute hypoxemic respiratory failure due to COVID-19, aspects of respiratory care and outcomes rapidly changed over the successive waves.
