Table 1.

Hazards for adverse drug events following hospital discharge, in six groups in the domains of home work system, hospital work system, collaborative work, and external environment.

Hazards	Examples
Home work system - medication task related
Complex dosing	Titrating, tapering, loading and maintenance doses Different doses of the same medication on different days Strict timing or conditions (e.g., every 6 hours, empty stomach) With instructions difficult to follow (e.g., “continue home regimen of insulin, 20 units of Lantus twice a day and your NovoLog insulin as needed three times a day”)
High risk medications	Narrow therapeutic index High potentials for drug-drug or drug-food interactions Potential for misuse or addiction
High burdens associated with medication use	Frequent follow-up care (e.g., clinic visits for monitoring and lab testing) Self-monitoring (e.g., blood glucose or monitoring for bruises) Difficult administration methods (e.g., injection or via special devices)
Lifestyle burdens associated with medication use	Side effects making compliance difficult Restrictions on diet or daily activities Interfering with daily, sleeping or social activities (e.g., void more frequently or to be taken at set time of the day)
Home work system – patient and caregiver related
Unsafe practices at home	Unwilling to accept increased lifestyle burden to take the medication Self-medicating for symptoms relief outside medical advice (e.g., taking multiple inhaler doses for COPD treatment) Work-arounds to reduce medication burdens (e.g., combining multiple doses in a day into a single dose) Under or improper use of safety tools (e.g., using pill boxes only as storage) Risky medication handling practices (e.g., multiple bottles of same medications in different doses, different medications in a single bottle)
Knowledge gaps	Not aware of taking duplicate or multiple similar action medications Confusion of brand versus generic names Not aware of importance of adherence or not fully understanding the risks of stopping a prescribed medication, often due to cost to medication side effects or improved symptoms Unaware of taking medications incorrectly Misbeliefs about medications Not aware of major risks or not aware of ways to reduce major risks Unable to provide accurate information on medications taken at home
At-risk behaviors in coping with cost	Holding on to expired or not current medications Reliance on coupons and free samples resulting gaps in therapies Stretching doses Patient’s reluctance to communicate about affordability Perception of unjustifiable high cost and/or low no benefits (e.g., not filling antibiotics when symptoms had resolved)
Gaps in knowledge and skills in managing regimen changes	Not understanding discharge medications as short-term bridging medications before seeing primary care physicians Not aware of temporary nature of regimen changes that require followup with primary care physicians who knew the patient
Home work system – resource related
Unaffordable cost	Medications with non-sustainable long-term cost No or inadequate insurance, or coverage gap Medications with high copay Medications requiring prior authorization
Deficiency in home support	Inadequate or no help needed at home (e.g., to administer discharge medications) Transportation barriers for followup visits or picking up medications Loss of prescriptions No system to ensure refill
Hospital work system
Errors in discharge medications	Unintentional duplications (same or medications with similar actions) Omissions or dose errors recorded in home medications Discontinued home medications listed as active Not resuming home medications upon discharge medications Inaccurate or missing allergy information in inpatient charts Unnecessary prescription of opioids or not using less risky alternatives
Communication barriers	Variations in discharge and communication processes over shifts or weekends resulting in gaps and confusions Difficulty adding instructions in EHR on discharge medications Inability to alert patients to dose changes Time pressure preventing thorough review and communication with patients on discharge medications No reliable process to review potential side effects and ways to manage side effects
Technology and policy barriers in helping patients manage cost	Difficulties in determining out-of-pocket cost to patients No process for engaging patients and families on cost and access issues Burdens in working on insurance coverage Cost issues induced from inpatient and outpatient formulary differences Hospital staff not having time or not aware of the need to address cost
Collaborative work between hospital and home work systems
Inadequate hand-offs for patients and caregivers to manage changes	Patients not aware, not educated on, or not prepared to manage new medications Mistaking dose changes as new medications or failure to adjust Lack of clear instructions and ability to resume or stop home medication
Inadequate understanding about changes	Switching from branded medication names to generic Switching within the same medication class due to formulary differences Changing chronic home medications
External environment
Medications unavailable after discharge	Pharmacies unable to dispense same medications with only dose changes due to insurance coverage restrictions Discharge medications not available at local pharmacies or requiring special orders
Gaps in access to care or in sharing medication information	Barriers to follow up visits with primary care provider (e.g., scheduling and insurance issues) Confusion over whom to reach out about refilling discharged medications Conflicting information to patients from different providers Medication information not shared across settings
Difficulties in obtaining medications after discharge	High burdens in meeting regulatory requirement to obtain medications Medications difficult to obtain outside hospital