Relationship Between (8 or 12-hour Shifts) and Medication Errors

“How long and how much are nurses now working?” is the question asked by Trinkoff, Geiger-Brown, Brady, Lipscomb, & Muntaner (2006). The answer of “too long, too much” causes concern given that the Institute of Medicine (IOM)

recommends nurses work no more than twelve hours in a 24-hour period (Trinkoff et al., 2006). Trinkoff et al. (2006) defined an extended work schedule as, “a schedule that varies from the standard one of eight hours per day, 35 to 40 hours per week”. Trinkoff studied 2,273 randomly selected nurses residing in two American states. The researchers found that more than a quarter of the sample reported that they are

typically working more than twelve hours per day, which goes against the recommendations of the IOM.

Do 12-hour shifts affect patient safety? Two separate studies, Rogers, Hwang, Scott, Aiken, & Dinges (2004), and Scott, Rogers, Hwang, & Zhang, (2006) used logbooks to collect error data associated with nurses. Both studies examined the logbooks to consider if work hours influenced the safety of the patient. In the first study, Rogers et al. (2004) used a broad sample of 393 full-time hospital staff nurses, who were

working over 40 hours a week. Log books were used to collect information including the number of hours worked and questions regarding medication errors by each nurse. The researchers stated that log books were used rather than incident reports to collect medication errors, for logbooks had been used in earlier field studies to collect data. Of the 30% of nurses that were scheduled to work a 12-hour shift, 39% of the shifts were over 12.5 hours long. It was found that of all the errors recorded in the log book, 58% were directly related to medication errors. Additionally, the results revealed that

1.6 % of the nurses working 8.5 hours or less had reported making one or more error, whereas 5% of nurses who worked 12.5 or more hours had one or more reported medication errors. When a nurse worked 12.5 hours or more in a shift, the risk of making a medication error significantly increased.

In the second study conducted by Scott et al. (2006), the random sample consisted of critical care nurses who were members of the American Association of Critical Care Nurses. The logbooks of 502 full-time CCU nurses were used to collect information regarding hours worked. Of the 44 % of nurses scheduled 12.5 hours, 62 % of the shifts were actually 12.5 hours or more. The authors reported that for nurses working eight and half hours or less; 2 % reported making at least one medication error. Whereas, for nurses working 12.5 hours or more per shift; 4 % reported making at least one medication error. It was evident that working longer hours increased the chances of making errors. When nurses worked 12.5 hours or more, the risk of making a medication error almost doubled. It is safe to conclude that long work hours pose serious threats to patient safety. Both studies above revealed that a nurse who worked 12.5 hours or more a day was at increased risk of making a medication error. This supports the IOM recommendations of nurses limiting work hours to no more than twelve hours in a 24-hour time period.

In the study conducted by Rogers et al. (2006), for the 393 hospital nurses that logged their errors, the occurrence of medication errors did not increase until the shifts exceeded 8.5 hours per day. The logbooks revealed that nurses working 8.5 hours or less consisted of 543 shifts (9%). Of these 543 only 11 (2 %) reported making at least one medication error, but it seems no matter the length of the shift, nurses are still at

risk of making a medication error. However, Rogers found no significant relationship between the nurses who worked 8.5 hours a day and medication errors. A limitation of this study, as reported by the researchers, was the inability to detect the effects of work hours on medication errors for nurses that were scheduled to work less than 12.5 hours a day.

In comparison, another study on staff nurse fatigue and patient safety reported that of 11,387 shifts examined, only 15.7 % of the nurses left at the end of their scheduled shift. Working only 8-hour shifts significantly decreased the risk of making errors. There was no differentiation in the risk of errors if they worked hours that were scheduled hours, mandatory overtime, or voluntary overtime (Rogers, 2008).

Mark & Belyea conducted a study in 2009 to examine the relationship between nurse staffing hours and medication errors. The sample for this study included data collected from 284 medical-surgical nursing wards in 145 hospitals. The data was collected from 911 RN’s working eight-hour shifts. This was a longitudinal study to examine the effects of nurse staffing hours on patient safety by the number of medication errors documented in incident reports. Mark & Belyea (2009) defined medication errors as an error in medication administration for wrong patient, drug, dose, time, or route. The data obtained by this study indicates there was only weak evidence to indicate a

relationship between work hours and medication errors. One of the limitations the authors stated in this study was that the data concerning medication errors were obtained from incident report data which was likely to underreport errors (Mark & Belyea, 2009).

Researchers have made important discoveries regarding the relationship between the long hours worked by nurses and medication errors. Many early studies show that long work hours pose serious threats to patient safety, however, it is not obvious so far that there is a relationship between twelve-hour shifts and the incidence of medication errors. Finally, a 12 European Countries study by Griffiths et al., 2014 concluded that RNs who worked 12 hours or more report lower quality and safety and more

unfinished care.

This study was conducted in Western Australia where the longest shift nursing staff work was typically the 10-hours night shift, a time where more errors were expected as the staff began to tire, but more likely to be discovered and reported in the morning shift following a night shift.