To the best of our knowledge, this is the first study to report on the PPV, NNA, and average time requirement using the modified IHI-endorsed ADE NH trigger tool. This research is important because improved surveillance of ADEs is particularly needed in the NH setting. The PPV reported in our study (40.1%) compares well to other screening tests used in clinical practice, such as the fecal occult blood test (PPVs ranging from 2% to 18%) which is recommend for all adults > 50 years of age by the United States Preventative Services Task Force.20
Furthermore, the NNA found in the current study (n=2.5) is less than that reported by previous work in which the NNA ranged from 4 to 25 charts reviewed across four types of ADE triggers among patients at a university-based teaching hospital.19
This may be a direct result of the comprehensive literature review and modified Delphi consensus process that was used to develop the triggers.10
However, we did not assess ADE causality in this study, which may have led to a lower NNA compared to previous work. Finally, the average time to complete resident screens seems reasonable and is consistent with recommendations from the IHI to spend no longer than 20 minutes reviewing each chart as this does not usually yield additional events.21
It is interesting to note the most common ADEs detected using the trigger tool in Veterans residing in NHs. We found that 5 triggers (i.e., AKI, hypokalemia, hypoglycemia, hyperkalemia, and hyponatremia) out of 27 were associated with almost 80% of the total potential ADEs detected. This is similar to a previous study by Singh et al (2009) who found that 9/39 triggers accounted for 94% of ADEs detected in an ambulatory care setting.22
This suggests that abbreviated versions of the trigger tool could potentially be used and still detect the majority of potential ADEs.
There are several potential implications of these findings. First, NH residents should have their medication regimens systematically reviewed in order to prevent and/or minimize ADEs. One suggestion could be that this modified ADE trigger tool be incorporated into the consultant pharmacist federally mandated medication regimen review (MRR) process, which is required to occur on a monthly basis for every U.S. NH resident. The U.S. State Operations Manual provides a definition for MRR (i.e., F428) as a thorough evaluation of the medication regimen of a resident, with the goal of promoting positive outcomes and minimizing adverse consequences.23
Incorporating the NH-specific ADE trigger tool into current practice could improve the quality of patient care in the NH setting without adding a substantial amount of time to complete MRRs. In addition to using trigger tool methods, the IHI and the Institute of Medicine recommend that NHs assess the safety of medication use through active monitoring systems.21,24
The use of active medication monitoring systems will undoubtedly become more feasible over time despite most NHs lagging behind the implementation and use of health information technology.25
Future research is needed to assess the impact of well-developed automated ADE detection systems on patient safety and healthcare spending in the NH setting.
There are several potential limitations that deserve mention. First, the cross-sectional design limits our ability to assess ADEs that may more commonly occur during other times of the year in the NH setting. Moreover, this was a retrospective study, which was a necessary first step to test the utility of the trigger tool. We also did not determine the causality of these potential ADEs, and we did not conduct inter-rater reliability statistics. However, the assessments conducted in this study were objective in nature and all reviewers were equally trained on how to conduct the chart reviews. As with any study conducted in the VA system, there are limitations to generalizability as the residents in this study were predominantly male and white. However, the population was elderly with multiple comorbidities, which is similar to NH residents within and outside of the VA. In addition, the trigger tool does not include all possible ADEs that can occur in the NH setting. For example, we included anemia (as indicated by a low or decreasing hemoglobin concentration) found in an individual taking a drug that may cause or worsen anemia (eg, nonsteroidal anti-inflammatory agents) in the initial set of laboratory/medication combination signals to determine a consensus list of signals that could be used to detect adverse drug events.10
However, this particular signal did not reach consensus agreement by a multidisciplinary panel of pharmacists, physicians, and advanced practitioners and was consequently not included in this study. Furthermore, we recognize that our trigger tool that is solely based on laboratory data will likely miss a significant number of ADEs. However, the current study was guided by the results of a previous study which was used to explicitly develop the triggers included in this and other studies. We intend on expanding the ADE trigger tool to include additional sources of data such as signs, symptoms, and incident/fall reports that could be used to detect such events.
It is important to keep in mind that reducing the number of false-positive triggers that need to be reviewed is particularly important to reduce trigger burden and more efficiently use the scarce resources available for ADE detection and management in the NH setting. One way to improve the efficiency of trigger tools recommended by the IHI is to modify or add/delete triggers based on the trigger-specific PPVs or on the needs of the facility, thus allowing for flexibility in the utility of trigger tools.21
In this study, we applied modifications deemed to enhance the clinical relevance of the laboratory cut-points for some of the triggers. In addition, the IHI recommends using the results of the trigger tool to measure the number of ADEs in a NH over time and to determine whether or not the changes a facility implements result in a reduction of ADEs.21
It is also important to recognize that the trigger tool methodology has been used in other clinical settings as well as in other countries for various other adverse events beyond medications.21
We recommend that a Delphi survey would need to be conducted prior to using the NH Trigger Tool in other countries due to differences in medication ascertainment and practices.
In conclusion, we found that the modified NH Trigger Tool was shown to be an effective and efficient method for detecting potential ADEs in the VA NH setting. Current ADE detection and management remain inadequate in the NH setting, and improved surveillance and novel approaches such as the ADE trigger tool are greatly needed. Future studies should be conducted (in both Veteran and non-Veteran populations) to assess the clinical impact of incorporating the trigger tool method for ADE detection by consultant pharmacists as part of monthly MRRs and through the use of computer decision support systems and active medication monitoring.