Top 10 causal factors and associated root causes of included pADEs
| Causal factor due to associated root cause | Example of type of pADE | % of all root causes | % of patients impacted by root cause |
| Patient had not understood information (possibly) previously provided due to provider not confirming patient understanding | Many different pADEs (except antibiotic related) | 35/281 (12.4) | 35/120 (29.2) |
| Unable to recognise medication side effect due to providers not confirming ability to do this | Bleeding, orthostatic hypotension, constipation | 28/281 (10.0) | 28/120 (23.3) |
| Prescribing (and not identified or managed at dispensing) antibiotics for CAP 25% of pADEs due to lack of referral to guideline | Unresolved pneumonia | 24/281 (8.5) | 24/120 (20) |
| Intentional non-adherence due to mainly not understanding purpose/benefit of medication±having concerns about taking it; provider not confirming that patient understands benefits/not identifying or addressing concern | Stroke, MI, aortic dissection, COPD, asthma, heart failure exacerbations | 20/281 (7.1) | 20/120 (16.7) |
| Medication monitoring provider (no actionable root cause identified: lack of system reminder, healthcare provider lapse, community pharmacy not routinely asking patient about bloodwork, except for lack of reminder on laboratory report to calculate phenytoin for low albumin n,1) | Acute kidney injury, hypothyroidism, phenytoin toxicity (n,1) | 18/281 (6.4) | 18/120 (15.0) |
| Could not identify if medication was working due to provider not confirming that patient can identify how medication is working and providing specific parameters (daily weighing, measuring BP) | Heart failure exacerbations, intracranial haemorrhage, hypertensive urgency | 17/281 (6.0) | 17/120 (14.1) |
| Patient did not have a sick day medication plan; due to lack of locally available resource in use, incorporation into routine practice; recognition of this as root cause in affected pADEs | Hypotension, acute kidney injury, elevated INR, bleeding, hypoglycaemia | 15/281 (5.3) | 15/120 (12.5) |
| Lack of provision of action plans for COPD, asthma or heart failure | COPD, asthma, heart failure | 13/281 (4.6) | 13/120 (10.8) |
| Provider not assessing medication use competency (ability to safely and reliably take medications) | Bleeding, drug toxicity, stroke | 12/281 (4.3) | 12/120 (10) |
| Provider had not adjusted medication based on laboratory parameters (actionable root cause not identified, presumed lapse by providers, laboratory results not available to community pharmacists) | Acute kidney injury, bleeding, stroke (due to hyperthyroidism) | 11/281 (3.9) | 11/120 (9.2) |
| Provider not assessing medication monitoring competency (ability to monitor for side effects or lack of effectiveness) | Bleeding, weakness, hypotension, heart failure, myxoedema | 11/281 (3.9) | 11/120 (9.2) |
BP, blood pressure; CAP, community-acquired pneumonia; COPD, chronic obstructive pulmonary disease; INR, international normalised ratio; MI, myocardial infarction; pADE, preventable adverse drug event.