Community exacerbations confirmed to 16/03/2021
* Hospital exacerbations confirmed to 31/08/2021
* How to use community events data post 16/03/2021
    * Option 1: Use them
    * Option 2: Don't use them and discard patient data for approx. 1 month around that event
    * Option 3: Attempt to verify them in a more automated way (looking at prescribing data etc)


* Rescue meds bnf codes
 steroid_codes = ['0603020T0AAACAC','0603020T0AABKBK', '0603020T0AAAXAX',
    '0603020T0AAAGAG','0603020T0AABHBH','0603020T0AAACAC','0603020T0AABKBK',
    '0603020T0AABNBN', '0603020T0AAAGAG', '0603020T0AABHBH']

    antib_codes = ['0501013B0AAAAAA', '0501013B0AAABAB', '0501030I0AAABAB',
    '0501030I0AAAAAA', '0501050B0AAAAAA', '0501050B0AAADAD', '0501013K0AAAJAJ']