Table 3.

Factors associated with incidence of DDIs

Factors		Description
Physician	Gender	The DDI incidence was significantly higher among male doctors [33,46].
	Age	Older physicians prescribed medications with more major DDIs than younger physicians (Not statistically significant) [46].
	Specialty	Major DDIs were higher in the prescriptions of specialist practitioners in comparison to general practitioners (cardiologists and internists ranked top on the list, while dermatologists ranked the lowest) [50].
		General practitioners had more prescriptions with major DDIs than specialists (statistically significant) [33].
		Significant level 1 DDIs1 were higher in prescriptions of internal specialists and cardiologists than other practitioners [31].
		Significant level 2 DDIs1 were higher in prescriptions of obstetrician and gynecologist than other practitioners [31].
		Significant level 3 DDIs1 were higher in prescriptions of general physicians than specialists [31].
		General physicians prescribed more medications with major DDIs than specialists (Not statistically significant) [46].
	Number of Prescriptions	Physicians with 150 or more prescriptions in one month had more DDIs than the others (statistically significant) [33].
Patient	Gender	DDIs were significantly higher in female patients [53].
		DDIs were significantly higher in male patients [42].
	Age	Clinically relevant DDIs were more common for patients 75 years or above than other patients [51].
		DDIs were significantly higher in patients aged over 60 years than other patients [42,53,57].
	Disease	DDIs were significantly higher in cardiology patients than other patients [53].
		DDIs were higher in Hematologic cancer patients than patients suffer from other diseases [57].
		DDIs were higher in patients whose source of cancer was in different specific organs than other cancer patients [57].
	Length of Hospital Stay	DDIs were higher in patients with longer hospital stay than other patients [42,57].
	Department	DDIs occurred in surgery department more than the other departments [36].
	Drug	DDIs was significantly higher in patients who have been prescribed digoxin than other patients [53].

¹Significance rating is based on Drug Interactions Facts™. The factors are related to physicians and patients’ characteristics.