Prior studies have demonstrated overutilization of PPI in the non-ICU inpatient setting 3–5
, as well as on medical subspecialty services 18,19
and in long-term nursing facilities 20
. This study demonstrates that PPI use is prevalent among non-ICU medical inpatients at a tertiary teaching hospital, nearly half of all medical inpatients over the course of the two-month study period received PPI during their inpatient stay, and that implementation of standardized guidelines may have a measurable impact on PPI utilization rates.
In the overall cohort, rates of inpatient PPI use and PPI prescriptions at discharge did not diminish following implementation of guidelines – suggesting, at face value, a negligible impact of the intervention. However, the impact of the intervention may be masked by the high rate of outpatient PPI use, and the fact that a higher percentage of patients reported outpatient PPI use at admission in post-guidelines compared with pre-guidelines study period (39% vs 34%). Among the cohort of patients not taking PPI at the time of admission, the rate of inpatient PPI use declined from 27% to 16% following implementation of guidelines (P=0.001), and the percentage of these patients receiving PPI prescriptions at discharge declined from 16% at baseline to 10% following implementation of guidelines (P=0.03). While this resulted in only 38 fewer inpatient PPI prescriptions and 21 fewer outpatient prescriptions over the course of a one month trial period on a selected inpatient population, the volume and impact of such a decline would be substantial when considered for hospital-wide implementation.
The strongest predictor of inpatient PPI use in our cohort was whether an individual patient reported PPI use at the time of admission. More than one third of patients (36%) reported PPI use at the time of admission. This is consistent with a prior study from an academic teaching hospital medical service, in which 29% of patients reported taking acid suppression medication prior to admission 5
. It is uncertain whether the strong impact of outpatient PPI use on inpatient PPI use represents continuation of appropriate outpatient PPI therapy for an accepted indication, continuation of outpatient PPI therapy (irrespective of indication) for inpatient prophylactic purposes, or rote continuation of an outpatient regimen without re-evaluation at the time of admission. Our study was not specifically designed to assess whether PPI therapy was appropriate on a patient-by-patient basis, and in our protocol providers were not asked to specify indications for PPI therapy. However, the study intervention (implementation of PPI guidelines) was designed to discourage use of PPI for prophylaxis of nosocomial UGIB in patients without clear risk factors for nosocomial UGIB.
Length of stay also predicted inpatient PPI therapy in our cohort, a finding consistent with prior published data 6
. It is uncertain whether this is a function of increased inpatient exposure providing increased opportunity for initiation of inpatient PPI therapy, development of an appropriate indication for PPI therapy, or a nonspecific marker of severity of illness.
The goal of the study was to assess PPI use for prophylactic purposes in a non-ICU setting. By design, therefore, the study cohort excluded patients with an alternative indication for PPI therapy, specifically patients with an admitting diagnosis of gastrointestinal bleeding. In addition, the cohort excluded patients admitted to the general medical ward from the ICU or medical step-down unit, as PPI therapy in these patients might reflect inadvertent continuation of stress ulcer prophylaxis initiated in the ICU in at-risk patients, rather than de novo PPI prophylaxis in average risk inpatients. While these exclusion criteria eliminate some potential confounders from our cohort, they may also limit the external validity of the study.
The study design posed several additional limitations. Much of the data were retrieved from chart review. Patient recall bias may have resulted in under- or over-reporting of outpatient medication use, including use of prescription or non-prescription PPI, and prescription or non-prescription aspirin or NSAIDs. Additional factors not included in the univariate or logistic regression analyses may have influenced inpatient PPI use. For instance, our analysis does not include measures of severity of illness or specific admitting diagnoses, which may be predictive of inpatient PPI therapy. In addition, we did not measure initiation of new inpatient antiplatelet or anticoagulant therapy, and are therefore unable to assess the influence of these medications on inpatient PPI use. We also did not measure rates of inpatient or outpatient use of histamine (H2)-receptor antagonists, and therefore cannot assess whether prescribers simply substituted these medications for PPIs following implementation of guidelines. Finally, this study was not designed to assess whether PPI utilization rates translate into any, either beneficial or adverse, meaningful clinical outcomes.
The developed set of guidelines are designed as a general framework for prescribing practices, do not address every clinical circumstance in which prophylactic PPI therapy might be considered, and are therefore subject to individual interpretation which may vary by provider. This reflects in part the relative lack of controlled, published data demonstrating specific risk factors for nosocomial UGIB in a non-ICU population, and also our desire to implement practical, easy-to-use guidelines which posed neither excessive restrictions nor a cumbersome algorithm. One can therefore argue that the introduction of guidelines and the subsequent measured decline in PPI utilization do not represent a true cause-and-effect relationship. There may be some natural variability in PPI utilization rates on a month-by-month basis, depending on the prescribing practices of individual providers rotating through the inpatient medical service. It is also conceivable that mere awareness that PPI utilization rates were being measured as part of this study, rather than an understanding of the guidelines, may have influenced provider prescribing practices. Therefore, while the results of this study should be considered hypothesis-generating, the potential financial and health-related impact of such an intervention may be significant, and our results should provide impetus for a more comprehensive, longer study to determine the impact of PPI guidelines on inpatient and outpatient PPI prescribing practices, rate of inpatient UGIB, and cost.
An important question is whether the observed decline in PPI utilization rates among a subset of inpatients will be durable and sustained following completion of this study. Our study was not designed to answer this question. Prior data have questioned both the sustained effectiveness and cost-effectiveness of interventions aimed at reducing prescriptions of acid suppressive drugs in the outpatient/general practitioner setting 21
. One option available in the inpatient setting, and which we are considering, is embedding a clinical decision support module in provider order entry (POE): when a health care provider attempts to order an inpatient PPI, the provider is prompted with a review of guidelines for appropriate PPI use, and is then offered the option to either continue with or abandon the PPI prescription. Data suggest that such prescribing computerized decision support systems do have the potential to alter provider behavior 22
, and might significantly enhance the impact of PPI prescribing guidelines among housestaff.
In summary, inpatient PPI therapy was prevalent in our cohort, with nearly half of all medical inpatients receiving an inpatient PPI, and more than 40% of patients prescribed PPI at hospital discharge. These figures appear to be driven by high outpatient rates of PPI use. Factors associated with inpatient PPI therapy include outpatient PPI use and length of stay. Implementation of standardized guidelines regarding appropriateness of inpatient PPI use results in a decrease in both inpatient and discharge PPI therapy among patients not receiving outpatient PPI therapy at the time of admission.