Despite the possibility of some selection bias they conclude that high doses of methylprednisolone are associated with worse outcomes and more frequent adverse effects (like prolonged hospital and ICU length of stay, higher hospital costs, increased length of invasive ventilation, increased need for insulin therapy and higher rate of fungal infections). Mortality itself did not significantly differ.
It is remarkable to note that in this study doses below 240mg of methylprednisolone are considered low-dose. This is equivalent to 300mg of prednisolone and is relatively high for exacerbations of COPD. As we mentioned in a post in November 2013 the REDUCE trial in JAMA compared 5 days to 14 days of steroids in exacerbated COPD. The dosage used there was 40mg of prednisone. The results showed that a 5-day treatment was non-inferior to a 14-day treatment with regard to re-exacerbation within 6 months but significantly reduced glucocorticoid exposure.
In summary it seems to be advisable to use lower doses and short treatment periods in acute exacerbated COPD.