What’s New in the Patient Safety World

August 2011

The “July Effect” Resurfaces



Our June 2010 What’s New in the Patient Safety World column “The July Effect: Myth or Reality?” discussed the July effect” in which less than optimal care is suspected to occur in academic hospitals when housestaff turn over. For years many have warned that the most dangerous time to be admitted to hospitals in the US was in July when new housestaff come on board. However, numerous studies in the past have been unable to corroborate that with good evidence.


A new systematic review (Young 2011) concludes that the “July effect” does exist. The authors reviewed 39 studies, spanning several decades, and noted that the studies are very heterogeneous and have conflicting conclusions. However, the studies of higher quality and larger sample sizes did show that mortality rates are higher and measures of efficiency lower during this period of year-end changeovers. They also note that there is almost no data regarding outcomes in ambulatory settings.


But the contributing factors are less clearcut, as pointed out by Young and colleagues and the accompanying editorial (Barach 2011). While the most obvious factor is new, relatively inexperienced housestaff coming on board, most studies lack details about the levels of supervision. But Young et al. are quick to point out that it is not just medical knowledge inexperience but also lack of familiarity with the new surroundings that may be important. You have to learn to navigate your way through the new system. In that regard, it might be useful to compare outcomes between those systems where residents are in only one hospital vs. those multi-hospital systems where residents rotate through a different hospital each month.


In our prior column we noted a study (Phillips and Barker 2010) that demonstrated a consistent July spike in deaths inside medical institutions coded as being due to fatal medication errors but only within counties having teaching hospitals. Moreover, the July spike was greater in those counties having a greater concentration of teaching hospitals. They found no similar spike for deaths of all causes or for deaths due to adverse medication effects (i.e. those medication-related deaths felt not to be preventable). Though the authors did consider potential alternative explanations (eg. more vacations in July, summer spikes in alcohol use and trauma, etc.) they conclude the most likely explanation for the “July effect” is the influx of new housestaff in teaching institutions. They also did not find evidence of a change in the July spike as new residency work hour rules came into effect.


Remember, everyone is changing over in July. You now have physicians who were interns yesterday becoming the supervisors of new interns today. And most teaching hospitals also have an influx of new nurses and maybe pharmacists around the same time. Some teaching hospitals also have new attendings starting and they often draw the summer months for their service commitments. The impact of vacations for healthcare personnel at all levels is another factor (remember that even vacations by clerical staff may put an additional burden on clinical staff). And summer vacation for school-agers also leads to more trauma and injuries related to outdoor activities and alcohol.


And before you blame the new first year housestaff, keep in mind our December 8, 2009 Patient Safety Tip of the Week “Prescribing Errors” which mentioned the EQUIP study (Dornan 2009) done in the UK on prescribing errors. Though originally established to look at prescribing errors made by first year residents, that study demonstrated that prescribing errors were both common and made by physicians at all levels. Looking at over 100,000 medication orders across 20 hospital sites, they found an average error rate of 8.9 errors per 100 medication orders. The error rate for first year residents, responsible for about half the orders, was 8.4% - actually lower than that for the entire group. All physician levels, including attendings, made prescribing errors. The highest rate (10.3%) was actually seen for second year residents. So perhaps some of the “July effect” might be due to staff at more advanced levels.


Young et al. do have some suggestions for possible interventions, including using more experienced (“our best attendings”) physicians as supervisors during July, minimizing housestaff fatigue, reducing the trainee workloads, making better use of physician extenders and better use of multidisciplinary teams, and even possibly staggering scheduled starts for new trainees.


Clearly, more research needs to be done to identify all the factors that may play a role in the “July effect” and more scientifically evaluate various interventions aimed at avoiding it.






Young JQ, Ranji SR, Wachter RM, et al. “July Effect”: Impact of the Academic Year-End Changeover on Patient Outcomes. A Systematic Review. Ann Intern Med 2011; 154: 000-000 published ahead of print July 11, 2011




Barach P, Philibert I. Editorial: The July Effect: Fertile Ground for Systems Improvement. Ann Intern Med July 11, 2011 E-352; published ahead of print July 11, 2011




Phillips DP, Barker  GEC. A July Spike in Fatal Medication Errors: A Possible Effect of New Medical Residents. J Gen Intern Med 2010; published online first June 2010




Dornan T, Ashcroft D, Heathfield H et al. An in depth investigation into causes of prescribing errors by foundation trainees in relation to their medical education. EQUIP study. December 2009















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