Online appendix 1: Preventability criteria (Schumoch & Thornton, 1992)

“Answering yes to one or more of the questions suggests that the DRP in question may indeed have been preventable”;
1. Was the drug involved in the ADR not considered appropriate for the patient’s clinical condition?
2. Was the dose, route, or frequency of administration inappropriate for the patient`s age, weight, or disease state?
3. Was the required therapeutic drug monitoring or other necessary laboratory test not performed?
4. Was there a history of allergy or previous reactions to the drug?
5. Was a drug interaction involved in the reaction?
6. Was a toxic serum drug level (or laboratory monitoring test) documented?
7. Was poor compliance involved in the reaction?

Online appendix2: Ten most frequent diagnoses using WHO-ICD10 classification

Diagnosis (ICD 10) / Cohort
n=737 (%) / KSA
n=364(%) / UK
n=373(%)
Symptoms, signs and abnormal clinical and laboratory findings (NOS)* / 113 (15.6) / 17 (4.7) / 96 (25.7)
Diseases of the respiratory system / 53 (7.2) / 20 (5.5) / 33 (8.8)
Neoplasms / 47 (6.4) / 31 (8.5) / 16 (4.3)
Injury, poisoning and certain other consequences of external causes / 35 (4.7) / 20 (5.5) / 15 (4.0)
Factors influencing health status and contact with health services / 66 (9.0) / 46 (12.6) / 20 (5.4)
Congenital malformations, deformations / 61 (8.3) / 32 (8.8) / 29 (7.8)
Certain conditions originating in the perinatal period / 64 (8.7) / 34 (9.3) / 30 (8.0)
Diseases of the digestive system / 51 (6.9) / 42 (11.5) / 10 (2.7)
Certain infectious and parasitic diseases / 37 (5.0) / 15 (4.1) / 22 (5.9)
Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism / 38 (5.2) / 14 (3.8) / 24 (6.4)
*NOS: not elsewhere classified

Online appendix 3: Details of the severe cases*

Patient age / Description of DRP / DRP category
14 months / Fentanyl infusion prescribed as 1mcg/kg/min instead of 1mcg/kg/hr. The order was prepared and sent to the ward with the wrong rate. But the problem was discovered by the consultant before starting administering the drug to the patient. / Dosing problem
1 year / Morphine infusion was prescribed as 40mcg/kg/min instead of 40mcg/kg/hr. Pharmacist contacted the prescriber to change the order. The prescriber agreed and wrote a new prescription with the correct infusion rate.
1 year / Epinephrine was prescribed as 4mg IM† instead of 0.04mg. Pharmacist contacted the prescriber to change the order. The prescriber agreed and wrote a new prescription.
1 day / Midazolam infusion prepared for wrong patient. Problem discovered at the stage of checking the prepared infusion against patient’s prescription,by the pharmacist, before sending the drug to the responsible nurse for that patient. / Others
*For the four cases: Preventability: Yes, Outcome of intervention: resolved.†IM: Intramascular