Prescribing Errors:Causes-and a Plan to “Do No Harm”

July 2, 2002

Because of the potential harm they pose to patients, prescribing errors continue to be a focus of attention in the medical literature.1-4 Indeed, the primary impetus for the creation of this column was to help prevent these errors.

 

Because of the potential harm they pose to patients, prescribing errors continue to be a focus of attention in the medical literature.1-4 Indeed, the primary impetus for the creation of this column was to help prevent these errors.

Recently, a prospective study examined the causes of prescribing mistakes. Dean and colleagues5 used theories of human error6 to gain an understanding of the underlying reasons for these errors (Table 1).

   
 Table 1 - Classification of error-producing conditions
  
 Work environment 
 Physical environment 
 Staffing (eg, inadequate staffing, new staff members or students, caring for other physicians' patients) 

 Individual factors 
 Physical health (eg, fatigue, hunger, illness) 
 Mental health (eg, low morale) 
 Skills and knowledge (eg, training, experience, calculations) 

 Team factors 
 Communication 
 Supervision 
 Responsibility 

 Task-related factors 
 Absence of protocols 
 Tasks that are not routine 

 Patient-related factors 
 Unhelpful patient 
 Complex disease 
 Language and communication problems 

 Adapted from Dean B et al. Lancet. 2002.

The study was conducted in a 550-bed teaching hospital in the United Kingdom. Because of the sensitive nature of this subject, prescribers were assured of the confidentiality of the results and of the nondisciplinary hospi- tal policy on errors. All prescribers were aware of the study, and any member of the medical staff was eligible for inclusion.

Pharmacists prospectively identified 88 potentially serious prescribing errors during the period from mid October to mid December 1999.1 The 41 prescribers who made 44 of the mistakes were interviewed, and the findings were analyzed using human error theory.

COMMON CAUSES OF ERRORS
Most of the prescribing errors resulted from "slips in attention" or the failure to apply relevant rules (Table 2). Certain conditions related to the work environment and to both the team and individual providers also led to prescribing errors (Table 3).

     
 Table 2 - Examples of active failures that can lead to prescribing errors 
     
 Type of active failure Example 

 Errors   
 Slips Two drugs were acceptable in a given setting: one was prescribed, but the dose for the alternative drug was mistakenly written. The prescriber had been distracted by interruptions. 

 Lapses A patient was switched from an immediate-release product to a sustained-release product on the discharge prescription; however, the prescriber forgot to delete the immediate-release product on the chart. 

 Mistakes The prescriber did not know that the dosage of ciprofloxacin must be decreased in a patient with renal failure. 

 Violations An attending physician checked the drug names a medical student had written and told the student to fill in the dosages; the attending physician failed to review the dosages later. 

 Adapted from Dean B et al. Lancet. 2002.



     
 Table 3 - Examples of conditions that can produce prescribing errors 
     
 Type of error-producing condition Examples 

 Related to work environment   
     Workload The prescriber has an excessive number of patients to cover or is on call 24 hours one day and has 12-hour shifts the rest of the time 

     Caring for other physicians' patients The physician who takes over the care of a patient finds no reason given in the chart for a drug to be started 

     Hurried prescribing The physician rushes to get the prescription to the pharmacy because of the delay in sending medications to the floor; prescriptions are written while the physician is on rounds 

 Related to the team An attending physician checked the drug names a medical student had written and told the student to fill in the dosages; the attending physician failed to review the dosages later. 
     Written communication Allergies are not documented in charts; messy charts 

     Verbal communication House officers simply “do as they are told” and thus fail to ask the attending physician or consultant about highly important drug interactions 

 Related to the individual   
     Hunger The prescriber has not eaten all night and hurries to finish 

     Tiredness Multiple medications need to be rewritten in a patient's chart in the middle of the night 

     Knowledge The prescriber is not familiar with the correct dosage of a drug 
     

 Adapted from Dean B et al. Lancet. 2002.

Latent conditions that were associated with errors included:

  • Lack of training about dose forms; dosing adjustments for decreased renal function; and the frequency, route, and duration of therapy.
  • Failure to transcribe orders with the same care used when prescribing a new drug.

Examples of defenses included reliance on the pharmacy to verify dosages-sometimes to the extent that the prescriber failed to look up the correct dosage.

RISK FACTORS FOR ERRORS
Physicians in the study identified the following risk factors for prescribing errors:

  • Uncomfortable physical work environment.
  • Inadequate staffing or new or student staff.
  • Heavy workload.
  • Prescribing for another physician's patient.
  • Lack of communication within the team.
  • Impaired physical and mental wellbeing.
  • Lack of knowledge.

Organizational factors that were identified included:

  • Inadequate training.
  • Low perceived importance of prescribing.
  • Hierarchical medical team.
  • Lack of awareness of errors

References:

REFERENCES:1. Lesar TS, Briceland L, Stein DS. Factors related to errors in medication prescribing. JAMA. 1997;277: 312-317.
2. Bond CA, Raehl CL, Franke T. Medication errors in United States hospitals. Pharmacotherapy. 2001;21: 1023-1036.
3. Ferner RE, Aronson JK. Medication errors, worse than a crime. Lancet. 2000;355:947-948.
4. Finch CK, Self TH. 10 Common prescribing errors: how to avoid them. Consultant. 2001;41:766-771.
5. Dean B, Schachter M, Vincent C, Barber N. Causes of prescribing errors in hospital inpatients: a prospective study. Lancet. 2002;359:1373-1378.
6. Reason J. Human Error. Cambridge, England: University of Cambridge Press; 1990.
7. Department of Health and Social Services. Central Health Services Council Report of the Joint Subcommittee on Measures for Controlling Drugs on Wards (The Gillie Report). HM(70)36. London: DHSS; 1970.

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