Proton pump inhibitors and risk of Clostridium difficile infection: a multi-country study using sequence symmetry analysis

Innovations in pharmacovigilance studies of medicines in older people

Pharmacovigilance is defined by the World Health Organization as "the science and activities relating to the detection, assessment, understanding and prevention of adverse effects or any other medicine/vaccine related problem". Pharmacovigilance studies are critical for detecting and assessing adverse events of medicines that may not have been observed in clinical trials. This activity is especially important in older people who are often excluded from clinical trials as they have multiple chronic conditions and use multiple medicines for longer durations than the clinical trials. In this narrative review we describe innovative methods in pharmacovigilance studies of medicines in older people that leverage the increasing availability of digital health technologies, electronic health records and real-world health data to identify and quantify medication related harms in older people.

Chronic Obstructive Pulmonary Disease Adverse Event Signals Associated with Potential Inhibitors of Glutathione Peroxidase 1: A Sequence Symmetry Analysis

BACKGROUND AND OBJECTIVE

Prior molecular modelling analysis identified several medicines as potential inhibitors of glutathione peroxidase 1 (GPx1) which may contribute to development or progression of chronic obstructive pulmonary disease (COPD). This study investigates 40 medicines (index medicines) for signals of COPD development or progression in a real-world dataset.

METHODS

Sequence symmetry analysis (SSA) was conducted using a 10% extract of Australian Pharmaceutical Benefits Scheme (PBS) claims data between January 2013 and September 2019. Patients must have been initiated on an index medicine and a medicine for COPD development or progression within 12 months of each other. Sequence ratios were calculated as the number of patients who initiated an index medicine followed by a medicine for COPD development or progression divided by the number who initiated the index medicine second. An adjusted sequence ratio (aSR) was calculated which accounted for changes in prescribing trends. Adverse drug event signals (ADEs) were identified where the aSR lower 95% confidence interval (CI) was greater than 1.

RESULTS

Twenty-one of 40 (53%) index medicines had at least one ADE signal of COPD development or progression. Signals of COPD development, as identified using initiation of tiotropium, were observed for atenolol (aSR 1.32, 95% CI 1.23-1.42) and naproxen (aSR 1.14, 95% CI 1.06-1.23). Several signals of COPD progression were observed, including initiation of fluticasone propionate/salmeterol following initiation of atenolol (aSR 1.44, 95% CI 1.30-1.60) and initiation of aclidinium/formoterol following initiation of naproxen (aSR 2.21, 95% CI 1.34-3.65).

CONCLUSION

ADE signals were generated for several potential GPx1 inhibitors; however, further validation of signals is required in large well-controlled observational studies.

Prescribing Cascades with Recommendations to Prevent or Reverse Them: A Systematic Review

BACKGROUND

To reduce prescribing cascades occurring in clinical practice, healthcare providers require information on the prescribing cascades they can recognize and prevent.

OBJECTIVE

This systematic review aims to provide an overview of prescribing cascades, including dose-dependency information and recommendations that healthcare providers can use to prevent or reverse them.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was followed. Relevant literature was identified through searches in OVID MEDLINE, OVID Embase, OVID CINAHL, and Cochrane. Additionally, Web of Science and Scopus were consulted to analyze reference lists and citations. Publications in English were included if they analyzed the occurrence of prescribing cascades. Prescribing cascades were included if at least one study demonstrated a significant association and were excluded when the adverse drug reaction could not be confirmed in the Summary of Product Characteristics. Two reviewers independently extracted and grouped similar prescribing cascades. Descriptive summaries were provided regarding dose-dependency analyses and recommendations to prevent or reverse these prescribing cascades.

RESULTS

A total of 95 publications were included, resulting in 115 prescribing cascades with confirmed adverse drug reactions for which at least one significant association was found. For 52 of these prescribing cascades, information regarding dose dependency or recommendations to prevent or reverse prescribing cascades was found. Dose dependency was analyzed and confirmed for 12 prescribing cascades. For example, antipsychotics that may cause extrapyramidal syndrome followed by anti-parkinson drugs. Recommendations focused on dosage lowering, discontinuing medication, and medication switching. Explicit recommendations regarding alternative options were given for three prescribing cascades. One example was switching to ondansetron or granisetron when extrapyramidal syndrome is experienced using metoclopramide.

CONCLUSIONS

In total, 115 prescribing cascades were identified and an overview of 52 of them was generated for which recommendations to prevent or reverse them were provided. Nonetheless, information regarding alternative options for managing prescribing cascades was scarce.

Overview of current detection methods and microRNA potential in Clostridioides difficile infection screening

Clostridioides difficile (formerly called Clostridium difficile, C. difficile) infection (CDI) is listed as an urgent threat on the 2019 antibiotic resistance threats report in the United States by the Centers for Disease Control and Prevention. Early detection and appropriate disease management appear to be essential. Meanwhile, although the majority of cases are hospital-acquired CDI, community-acquired CDI cases are also on the rise, and this vulnerability is not limited to immunocompromised patients. Gastrointestinal treatments and/or gastrointestinal tract surgeries may be required for patients diagnosed with digestive diseases. Such treatments could suppress or interfere with the patient’s immune system and disrupt gut flora homeostasis, creating a suitable microecosystem for C. difficile overgrowth. Currently, stool-based non-invasive screening is the first-line approach to CDI diagnosis, but the accuracy is varied due to different clinical microbiology detection methods; therefore, improving reliability is clearly required. In this review, we briefly summarised the life cycle and toxicity of C. difficile, and we examined existing diagnostic approaches with an emphasis on novel biomarkers such as microRNAs. These biomarkers can be easily detected through non-invasive liquid biopsy and can yield crucial information about ongoing pathological phenomena, particularly in CDI.

Vonoprazan poses no additional risk of developing Clostridioides difficile infection compared to proton pump inhibitors

BACKGROUND AND AIM

The use of proton pump inhibitors (PPIs) has been repeatedly reported as a trigger of Clostridioides difficile infection (CDI), a leading cause of nosocomial diarrhea. However, only a few studies have reported on the association between vonoprazan, a novel potassium-competitive acid blocker providing potent acid suppression, and CDI, with no studies having been conducted in a clinical setting. We therefore evaluated the association between various classes of acid suppressants and CDI with special attention paid to differences in the magnitudes of association between PPIs and vonoprazan.

METHODS

A retrospective hospital-based cohort from a secondary-care hospital in Japan (n = 25 821) was collected, wherein eligible CDI cases were defined as hospital-onset cases (n = 91). A multivariable adjusted logistic regression analysis for the entire cohort and propensity analyses for subgroups consisting of PPI and/or vonoprazan users at various doses (n = 10 306) were performed.

RESULTS

The overall CDI incidence rate was 1.42/10 000 patient-days, which was comparable with previous reports. A multivariable analysis showed that both PPIs and vonoprazan were positively associated with CDI (odds ratios [95% confidence intervals]: 3.15 [1.67-5.96] and 2.63 [1.01-6.88], respectively). In addition, matched subgroup analyses showed that PPIs and vonoprazan had equivalent magnitudes of association with CDI.

CONCLUSIONS

We found that both PPIs and vonoprazan were associated with CDI, and the magnitude of the association was comparable. Because vonoprazan is widely available in Asian countries, further studies on the association of its usage with CDI are warranted.

Prescribing Cascades: How to Detect Them, Prevent Them, and Use Them Appropriately

BACKGROUND

A prescribing cascade is the treatment of an adverse drug reaction (ADR) with another drug. In this review, we discuss (a) the different types of prescribing cascade and (b) the measures that can be taken so that they will be recognized and dealt with appropriately, both in the hospital and in the outpatient setting.

METHODS

This review is based on pertinent publications retrieved by a selective literature search.

RESULTS

The literature distinguishes intentional from unintentional prescribing cascades, and appropriate from inappropriate ones. We further distinguish prophylactic from therapeutic prescribing cascades and draw a line between those that are necessary and those that are merely appropriate. The following main questions are essential for dealing with prescribing cascades appropriately: (1) Did the precipitating drug cause a clinically relevant ADR or risk of an ADR? (2) Is the precipitating drug still indicated? (3) Can an ADR be avoided by altering the treatment with the precipitating drug, or by (4) switching to another drug instead? (5) Can the drug used to treat the ADR actually affect it beneficially? (6) Do the benefits of the prescribing cascade outweigh its risks?

CONCLUSION

Prescribing cascades are not problematic in themselves; on the contrary, they are sometimes a necessary part of good prescribing practice. There is still a lack of practically implementable instruments to help physicians detect prescribing cascades reliably, assess them properly, and put them to appropriate use.

Prescribing cascades in community-dwelling adults: A systematic review

The misattribution of an adverse drug reaction (ADR) as a symptom or illness can lead to the prescribing of additional medication, referred to as a prescribing cascade. The aim of this systematic review is to identify published prescribing cascades in community-dwelling adults. A systematic review was reported in line with the PRISMA guidelines and pre-registered with PROSPERO. Electronic databases (Medline [Ovid], EMBASE, PsycINFO, CINAHL, Cochrane Library) and grey literature sources were searched. Inclusion criteria: community-dwelling adults; risk-prescription medication; outcomes-initiation of new medicine to "treat" or reduce ADR risk; study type-cohort, cross-sectional, case-control, and case-series studies. Title/abstract screening, full-text screening, data extraction, and methodological quality assessment were conducted independently in duplicate. A narrative synthesis was conducted. A total of 101 studies (reported in 103 publications) were included. Study sample sizes ranged from 126 to 11 593 989 participants and 15 studies examined older adults specifically (≥60 years). Seventy-eight of 101 studies reported a potential prescribing cascade including calcium channel blockers to loop diuretic (n = 5), amiodarone to levothyroxine (n = 5), inhaled corticosteroid to topical antifungal (n = 4), antipsychotic to anti-Parkinson drug (n = 4), and acetylcholinesterase inhibitor to urinary incontinence drugs (n = 4). Identified prescribing cascades occurred within three months to one year following initial medication. Methodological quality varied across included studies. Prescribing cascades occur for a broad range of medications. ADRs should be included in the differential diagnosis for patients presenting with new symptoms, particularly older adults and those who started a new medication in the preceding 12 months.

Generating Real-World Evidence on the Quality Use, Benefits and Safety of Medicines in Australia: History, Challenges and a Roadmap for the Future

Australia spends more than $20 billion annually on medicines, delivering significant health benefits for the population. However, inappropriate prescribing and medicine use also result in harm to individuals and populations, and waste of precious health resources. Medication data linked with other routine collections enable evidence generation in pharmacoepidemiology; the science of quantifying the use, effectiveness and safety of medicines in real-world clinical practice. This review details the history of medicines policy and data access in Australia, the strengths of existing data sources, and the infrastructure and governance enabling and impeding evidence generation in the field. Currently, substantial gaps persist with respect to cohesive, contemporary linked data sources supporting quality use of medicines, effectiveness and safety research; exemplified by Australia's limited capacity to contribute to the global effort in real-world studies of vaccine and disease-modifying treatments for COVID-19. We propose a roadmap to bolster the discipline, and population health more broadly, underpinned by a distinct capability governing and streamlining access to linked data assets for accredited researchers. Robust real-world evidence generation requires current data roadblocks to be remedied as a matter of urgency to deliver efficient and equitable health care and improve the health and well-being of all Australians.

Proton pump inhibitors may contribute to progression or development of chronic obstructive pulmonary disease-A sequence symmetry analysis approach

WHAT IS KNOWN AND OBJECTIVE

Proton pump inhibitors (PPIs), used to treat and prevent gastro-oesophageal conditions, are well-tolerated but have been associated with risk including pneumonia. The extent to which initiation of PPIs can contribute to other respiratory conditions such as chronic obstructive pulmonary disease (COPD) is largely unknown.

METHODS

A sequence symmetry analysis (SSA) approach was applied to the Australian Department of Human Services, Pharmaceutical Benefits Scheme 10% extract. Participants were aged 45 years and older and were dispensed PPIs (ATC Codes A02BC01, A02BC02, A02BC03, A02BC04 and A02BC05) and long-acting bronchodilators (LABDs) for COPD (ATC Codes R03BB04 (PBS Item Code 10509D and 08626B), R03BB05, R03BB06, R03BB07 and R03AC18 (PBS Item Code 05137J and 05134F)) between 2013 and 2019. The analysis included patients initiated on an LABD within 12 months before or after their first prescription of a PPI. The crude sequence ratio (cSR) was calculated as the number of patients prescribed their first LABD after starting a PPI divided by the number of patients prescribed their first LABD before starting a PPI. Calculation of the adjusted sequence ratio (aSR) accounted for prescribing trends over time in initiation of each of the medicines. A signal was identified where the aSR lower 95% confidence interval (CI) was greater than one.

RESULTS AND DISCUSSION

Initiation of omeprazole was associated with a 29% increased risk of initiating a LABD (ASR = 1.29 95% CI 1.22-1.36). Initiation of esomeprazole, rabeprazole, pantoprazole or lansoprazole was associated with 25%, 15%, 8% and 8% increased risk, respectively.

WHAT IS NEW AND CONCLUSION

There is an established association between gastro-oesophageal reflux disease and COPD which has been confirmed by implementation of a sequence symmetry-based approach which demonstrated that PPI initiation is potentially associated with progression or exacerbation of COPD. The impact PPI use has directly on this association requires further investigation.

Evaluating the use of prescription sequence symmetry analysis as a pharmacovigilance tool: A scoping review

BACKGROUND

The (prescription) sequence symmetry analysis (PSSA) design has been used to identify potential prescribing cascade signals by assessing the prescribing sequence of an index drug relative to a marker drug presumed to treat an adverse drug event provoked by the index drug.

OBJECTIVES

This review aimed to explore the use of the PSSA design as a pharmacovigilance tool with a particular focus on the breadth of identified signals and advances in PSSA methodology.

METHODS

We searched Embase, PubMed/Medline, Google Scholar, Web of Science and grey literature to identify studies that used the PSSA methodology. Two reviewers independently extracted relevant data for each included article. Study characteristics including signals identified, exposure time window, stratified analyses, and use of controls were extracted.

RESULTS

We identified 53 studies which reported original results obtained using PSSA methodology or quantified the validity of components of the PSSA design. Of those, nine studies provided validation metrics showing reasonable sensitivity and high specificity of PSSA to identify prescribing cascade signals. We identified 340 unique index drug - marker drug signals published in the PSSA literature, representing 281 unique index - marker pharmacological class dyads (i.e., unique fourth-level Anatomical Therapeutic Chemical [ATC] classification dyads). Commonly observed signals were identified for index drugs acting upon the nervous system (34%), cardiovascular system (21%), and blood and blood-forming organs (15%), and many marker drugs were related to the nervous system (25%), alimentary tract and metabolism (23%), cardiovascular system (17%), and genitourinary system and sex hormones (14%). Negative controls and positive controls were utilized in 21% and 13% of studies, respectively.

CONCLUSIONS

The PSSA methodology has been used in 53 studies worldwide to detect and evaluate over 300 unique prescribing cascades signals. Researchers should consider sensitivity analyses incorporating negative and/or positive controls and additional time windows to evaluate time-varying biases when designing PSSA studies.

Potent Acid Suppression With Vonoprazan vs Proton Pump Inhibitors Does Not Have Higher Association With Clostridioides difficile Infection

INTRODUCTION

Proton pump inhibitors (PPIs) are associated with the onset of Clostridioides difficile infection (CDI). Although a new potassium-competitive acid blocker, vonoprazan, consistently shows a more potent acid inhibitory effect in comparison to PPIs, the risk of CDI in vonoprazan-treated patients relative to those treated with PPIs is unknown. In this retrospective case-control study, using a nationwide hospital-based administrative database in Japan, we investigated the association of the onset of CDI in patients treated with vonoprazan.

METHODS

A CDI case was defined as a case in which a patient was diagnosed and treated for CDI. For each CDI case, 3 non-CDI patients were extracted as controls. Information on the usage of acid suppressants in the 2 months before the onset of CDI and other confounding factors was collected. Relative associations of gastric acid suppressants with the onset of CDI were estimated.

RESULTS

A total of 4,466 CDI cases and 13,220 of non-CDI controls were extracted. A multivariate conditional regression analysis revealed that PPI or vonoprazan use was modestly, but significantly associated with CDI (odds ratio [95% confidence interval]: PPI, 1.3 [1.2-1.4]; vonoprazan, 1.4 [1.2-1.7]). With PPI users as a reference, vonoprazan did not show a stronger association with CDI (odds ratio [95% confidence interval]: 1.07 [0.91-1.26]).

DISCUSSION

We found a significant positive association between vonoprazan use and CDI; however, the magnitude of the association was not beyond that in PPI users. This is the first report on any potential adverse effects of vonoprazan.

Real-world evidence of population differences in allopurinol-related severe cutaneous adverse reactions in East Asians: A population-based cohort study

Abstract

Allopurinol‐related severe cutaneous adverse reactions (SCARs) are strongly associated with HLA‐B*58:01, the allele frequency (AF) of which is largely different among East Asians. However, evidence of population differences in SCAR development and relevance of genetic and/or other risk factors in the real‐world remain unelucidated. This study aimed to evaluate population differences in allopurinol‐related SCAR incidence related to genetic and/or other risk factors among East Asians in the real‐world. A population‐based cohort study was conducted using claims databases from Taiwan, Korea, and Japan. New users of allopurinol (311,846; 868,221; and 18,052 in Taiwan, Korea, and Japan, respectively) were followed up to 1 year. As control drugs, phenytoin and carbamazepine were used. The crude incidence rate ratios (IRRs) of SCARs for allopurinol against phenytoin or carbamazepine were the highest in Taiwan (IRR, 0.62 and 1.22; 95% confidence interval [CI], 0.54–0.72 and 1.01–1.47, respectively), followed by Korea (IRR, 0.34 and 0.82; 95% CI, 0.29–0.40 and 0.77–0.87), and the lowest in Japan (IRR, 0.04 and 0.16; 95% CI, 0.02–0.08 and 0.09–0.29). This order was accordant with that of AF ratios (AFRs) reported of HLA‐B*58:01 against alleles responsible for phenytoin‐ or carbamazepine‐related SCARs. The IRRs were higher in patients with chronic kidney disease, females, and elderly. This study demonstrated population differences in the risk of allopurinol‐related SCAR development among East Asians based on genetic and other common risk factors. This finding will help to promote appropriate risk management for allopurinol‐related SCARs based on ethnic origins.

Impact of NPS MedicineWise general practitioner education programs and Choosing Wisely Australia recommendations on prescribing of proton pump inhibitors in Australia

Background

This study evaluated the impact of multifaceted NPS MedicineWise programs that targeted all general practitioners (GPs) in Australia in 2009 and 2015 with the aim of reducing unnecessary prescribing of proton pump inhibitors (PPIs) and encouraged stepping down to a lower strength PPI or to discontinue treatment. The 2015 intervention coincided with the release of Choosing Wisely Australia recommendations from the Royal Australian College of General Practitioners (RACGP).

Methods

Outcome measures included monthly dispensing rates of different strength PPIs prescribed by GPs to concessional patients in Australia. All PPIs were categorized according to the May 2019 revised classifications for standard and low strength PPIs except for esomeprazole 40 mg which was classified as a standard strength and esomeprazole 20 mg as low strength for this analysis. Time series analyses was conducted of the dispensing rates of PPI prescriptions for concessional patients between January 2006 and June 2016 using the Pharmaceutical Benefits Scheme (PBS) and Medicare Benefits Schedule (MBS) databases in Australia. Participants were GPs with dispensed PPI prescriptions to concessional patients between January 2006 and June 2016.

Results

Following the 2009 NPS MedicineWise program we observed a 6.7% reduction in the expected dispensing rate of standard strength PPIs for concessional patients between April 2006 and March 2015, and an 8.6% reduction between April 2009 and June 2016 following the 2015 program launch. We observed a significant increase of 5.6% in the dispensing rate of low strength PPIs for concessional patients between April 2009 and March 2015, and no significant change in trend following the 2015 program.

Conclusions

The NPS MedicineWise programs were associated with reductions in the dispensing rate of standard strength PPIs by June 2016 and an increase in the dispensing rate of low-strength PPIs by March 2015 although this trend did not continue following the 2015 program. This suggests that GPs are stepping down patients to lower strength PPIs following the educational programs. However, lower strength PPIs are still not the majority of PPIs dispensed in Australian and regular interventions to sustain and improve PPI management by GPs may be warranted.

Recommendations and guidelines for the treatment of Clostridioides difficile infection in Taiwan

Clostridioides difficile infection (CDI) is a major enteric disease associated with antibiotic use and a leading cause of hospital-acquired infections worldwide. This is the first guideline for treatment of CDI in Taiwan, aiming to optimize medical care for patients with CDI. The target audience of this document includes all healthcare personnel who are involved in the medical care of patients with CDI. The 2018 Guidelines Recommendations for Evidence-based Antimicrobial agents use in Taiwan (GREAT) working group was formed, comprising of infectious disease specialists from 13 medical centers in Taiwan, to review the evidence and draft recommendations using the grading of recommendations assessment, development, and evaluation (GRADE) methodology. A nationwide expert panel reviewed the recommendations during a consensus meeting in March 2019. The recommendation is endorsed by the Infectious Diseases Society of Taiwan (IDST). This guideline describes the epidemiology and risk factors of CDI, and provides recommendations for treatment of CDI in both adults and children. Recommendations for treatment of the first episode of CDI, first recurrence, second and subsequent recurrences of CDI, severe CDI, fulminant CDI, and pediatric CDI are provided.

The Impact of Bariatric Surgery on Short Term Risk of Clostridium Difficile Admissions

BACKGROUND AND AIMS

Clostridium difficile infection (CDI) is major health care concern with reports linking it to obesity. Our aim was to investigate the little known impact of the two most common bariatric surgeries, Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG), on risk of CDI admissions.

METHODS

This is a retrospective cohort study using the 2013 Nationwide Readmission Database. We examined inpatient CDI rates within 120 days after RYGB (n = 40,059) and VSG (n = 45,394). In a time to event analysis we also evaluated inpatient CDI rates up to 11 months post-surgery. We chose morbidly obese patients that underwent non-emergent ventral hernia repair (VHR) as additional surgical controls (n = 9673).

RESULT

CDI rates were higher after RYGB than VSG in the first 30 days (odds ratio [OR] = 2.10; 95% confidence interval [CI], 1.05-4.20) with a similar but nonsignificant trend within 31-120 days. CDI rates were also higher after RYGB compared to VHR controls within 31-120 days after surgery (OR = 3.22, 95%CI: 1.31, 7.88, p = 0.01). In a time to event analysis with up to 11 months follow up, RYGB led to higher CDI compared to VSG (hazard ratio [HR] = 1.87; 95% CI, 1.12-3.13) with a trend towards higher CDI compared to VHR (HR = 1.95; 95% CI, 0.94-4.06). Similar CDI rates occurred after VSG vs VHR.

CONCLUSIONS

RYGB may increase the risk of CDI hospitalization when compared to VSG and VHR controls. This data suggest VSG may be a better bariatric choice when post-surgical CDI risk is a concern.

Proton pump inhibitors and 180-day mortality in the elderly after Clostridium difficile treatment

Background

There is a reported association between proton pump inhibitor (PPI) exposure and increased risk of Clostridium difficile infection (CDI), but less is known about how this class of medications taken during treatment might influence mortality after CDI. Here we examine 180-day mortality rates in a cohort of CDI elders and its association with exposure to PPIs. We conducted a retrospective cohort study of elderly patients (> 65 years of age) diagnosed and treated for CDI in the years 2014–2016 (n = 874) in the Umass Memorial Health Care system, which represents both academic and community healthcare. Patient characteristics and medication use was extracted from the electronic medical record (EMR) and 6 month mortality data was obtained via the Center for Disease Control National Death Index. A Cox proportional hazards model was used to estimate hazard ratios associated with medication exposures and other relevant variables.

Results

Of the 874 elderly adults treated for CDI, 180-day all-cause mortality was 12.4%. Exposure to a PPI was associated with a 55% reduced risk of mortality (adjusted hazard ratio (aHR) 0.45; 95% confidence interval (CI) 0.28–0.72). In our Cox model, increasing age (aHR 1.45; 95% CI 1.14–1.84), those with severe CDI infections (aHR 1.87; 95% CI 1.22–2.88), and those with hospital acquired CDI (aHR 3.01; 95% CI 1.81–4.99) also had increased 180 day mortality risk. There were similar associations noted with both 90 day and 1-year mortality.

Conclusion

Use of PPIs during CDI treatment in elderly patients is associated with decreased 180-day mortality. Although use of PPIs has been associated with an increased risk of CDI, it appears to be protective against mortality when used during the treatment phase.

Taiwan's National Health Insurance Research Database: past and future

Taiwan's National Health Insurance Research Database (NHIRD) exemplifies a population-level data source for generating real-world evidence to support clinical decisions and health care policy-making. Like with all claims databases, there have been some validity concerns of studies using the NHIRD, such as the accuracy of diagnosis codes and issues around unmeasured confounders. Endeavors to validate diagnosed codes or to develop methodologic approaches to address unmeasured confounders have largely increased the reliability of NHIRD studies. Recently, Taiwan's Ministry of Health and Welfare (MOHW) established a Health and Welfare Data Center (HWDC), a data repository site that centralizes the NHIRD and about 70 other health-related databases for data management and analyses. To strengthen the protection of data privacy, investigators are required to conduct on-site analysis at an HWDC through remote connection to MOHW servers. Although the tight regulation of this on-site analysis has led to inconvenience for analysts and has increased time and costs required for research, the HWDC has created opportunities for enriched dimensions of study by linking across the NHIRD and other databases. In the near future, researchers will have greater opportunity to distill knowledge from the NHIRD linked to hospital-based electronic medical records databases containing unstructured patient-level information by using artificial intelligence techniques, including machine learning and natural language processes. We believe that NHIRD with multiple data sources could represent a powerful research engine with enriched dimensions and could serve as a guiding light for real-world evidence-based medicine in Taiwan.

Taiwan's National Health Insurance Research Database: past and future

Taiwan’s National Health Insurance Research Database (NHIRD) exemplifies a population-level data source for generating real-world evidence to support clinical decisions and health care policy-making. Like with all claims databases, there have been some validity concerns of studies using the NHIRD, such as the accuracy of diagnosis codes and issues around unmeasured confounders. Endeavors to validate diagnosed codes or to develop methodologic approaches to address unmeasured confounders have largely increased the reliability of NHIRD studies. Recently, Taiwan’s Ministry of Health and Welfare (MOHW) established a Health and Welfare Data Center (HWDC), a data repository site that centralizes the NHIRD and about 70 other health-related databases for data management and analyses. To strengthen the protection of data privacy, investigators are required to conduct on-site analysis at an HWDC through remote connection to MOHW servers. Although the tight regulation of this on-site analysis has led to inconvenience for analysts and has increased time and costs required for research, the HWDC has created opportunities for enriched dimensions of study by linking across the NHIRD and other databases. In the near future, researchers will have greater opportunity to distill knowledge from the NHIRD linked to hospital-based electronic medical records databases containing unstructured patient-level information by using artificial intelligence techniques, including machine learning and natural language processes. We believe that NHIRD with multiple data sources could represent a powerful research engine with enriched dimensions and could serve as a guiding light for real-world evidence-based medicine in Taiwan.

Characterization and risk factors for recurrence of Clostridioides (Clostridium) difficile infection in Japan: A nationwide real-world analysis using a large hospital-based administrative dataset

OBJECTIVE

Recurrent Clostridioides (Clostridium) difficile infection (rCDI) is common and increases healthcare resource utilization. In this study, we assessed rCDI risk factors using an up-to-date, Japanese national hospital-based database.

METHODS

C. difficile infection (CDI) episodes, occurring July 2014-June 2017, in patients aged ≥18 years were extracted from the database and a nested case-control analysis was performed. Cases were defined as rCDI episodes which required re-initiation of oral vancomycin or oral/intravenous metronidazole treatment within 8 weeks from the start of initial treatment. Cases were matched to 4 non-rCDI episodes at the timing of rCDI occurrence. Adjusted odds ratios (ORs) were estimated using multivariate conditional logistic regression model.

RESULTS

Of 18,246 initial CDI episodes, 3250 (17.8%) had at least one rCDI. Approximately 90% of episodes occurred in inpatients and 65% were treated with metronidazole. Older age (<75 years vs 75-84 years and vs 85 + years) was associated with higher risk of rCDI (OR = 1.27, 95% confidence interval [1.15, 1.41] and 1.45 [1.30, 1.61], respectively). Use of systemic antibiotics (3.16 [2.90, 3.44]), probiotics (2.53 [2.32, 2.77]), chemotherapy (1.28 [1.08, 1.53]), or proton pump inhibitors (PPIs) (1.17 [1.07, 1.28]), and prior CDI history (1.22 [1.03, 1.43]) were also identified as rCDI risk factors. Vancomycin reduced the risk of rCDI compared with metronidazole treatment (0.83 [0.76, 0.91]).

CONCLUSION

This large, multicenter, nationwide study confirmed that older age, PPIs, antibiotics, probiotics, chemotherapy, and prior CDI history are risk factors for rCDI in Japan. There was a 17% decrease of rCDI risk with vancomycin vs metronidazole treatment.

CLINICAL TRIAL REGISTRATION NUMBER

N/A.

The risks of long-term use of proton pump inhibitors: a critical review

Proton pump inhibitors (PPIs) are among the most frequently prescribed medications. Their use is likely even higher than estimated due to an increase in the number of PPIs available without a prescription. Appropriate indications for PPI use include Helicobacter pylori infection, erosive esophagitis, gastric ulcers, and stress ulcer prevention in high-risk critically ill patients. Unfortunately, PPIs are often used off-label for extended periods of time. This increase in PPI usage over the past two decades has called into question the long-term effects of these medications. The association between PPI use and infection, particularly Clostridium difficile and pneumonia, has been the subject of several studies. It’s proposed that the alteration in gastrointestinal microflora by PPIs produces an environment conducive to development of these types of infections. At least one study has suggested that long-term PPI use increases the risk of dementia. Drug interactions are an important and often overlooked consideration when prescribing any medication. The potential interaction between PPIs and antiplatelet agents has been the subject of multiple studies. One of the more recent concerns with PPI use is their role in the development or progression of chronic kidney disease. There is also some literature suggesting that PPIs contribute to the development of various micronutrient deficiencies. Most of the literature examining the potential adverse effects of PPI use is composed of retrospective, observation studies. There is a need for higher quality studies exploring this relationship.

Assessment of Medication Safety Using Only Dispensing Data

PURPOSE OF REVIEW

The purpose of this review is to provide an overview of the published studies that have been used to generate evidence on the safety of medicine use when only medication dispensing data are available.

RECENT FINDINGS

Medication dispensing databases are increasingly available for research on large populations, particularly in countries that provide universal coverage for medicines. These data are often used for drug utilisation studies to identify inappropriate medicine use at the population level that may be associated with known safety issues. Lack of coded diagnoses, to identify outcomes, and lack of data on confounders can limit use of these data in practice for medication safety assessment. To overcome these issues, studies have exploited the fact that symptoms of adverse effects of medications can be treated with other medications, for example antidepressants to treat depression or oxybutynin to treat urinary incontinence. The challenge of unmeasured confounding has been addressed by implementing self-controlled study designs that use within-person comparisons and provide inherent control for confounding. Prescription sequence symmetry analysis (SSA) is a within-person study design that has been demonstrated as a useful tool for safety signal generation in dispensing data.

SUMMARY

Using medicine initiation as a proxy for the development of adverse events can help to generate evidence of the safety of medicines when only medication dispensing data are available. Careful consideration, however, should be given to the sensitivity and specificity of the proxy medicine for the adverse event and potential for time-varying confounding due to trends in medicine utilisation. Data-mining approaches using dispensing data have the potential to improve safety assessments; however, the challenge of unmeasured confounding with these methods remains to be investigated.

Gastroesophageal Reflux Characteristics and Patterns in Patients with Idiopathic Subglottic Stenosis

Introduction

Idiopathic subglottic stenosis represents a spectrum of subglottic disease without a clear underlying cause. Prior studies have implicated a pathogenic role of gastroesophageal reflux disease in idiopathic subglottic stenosis. The aim of this study was to examine the presence and pattern of gastroesophageal reflux in a large cohort of patients with idiopathic subglottic stenosis at a tertiary referral center.

Methods

We performed a retrospective review of patients with idiopathic subglottic stenosis from January 2010 to December 2016 who had undergone combined pH impedance testing. Patients with prior gastric or esophageal surgery were excluded. Data obtained included esophageal acid exposure times, number of reflux events, patient position during reflux events (defined as upright, supine, or mixed), body mass index, and the presence of proton pump inhibitor therapy.

Results

159 patients with the idiopathic subglottic stenosis were identified, of whom 41 had undergone esophageal pH impedance testing. 40 (97.6%) were women, with a mean age of 54.8 (range 31-79) years and BMI of 31.0 (range 17-55). Overall, 19 (46.3%) patients were found to reflux as confirmed by abnormal esophageal acid exposure or abnormal number of reflux events. 15 of the 19 patients with reflux had predominantly upright gastroesophageal reflux disease, whereas 2 had supine and 2 mixed reflux.

Discussion

In patients with idiopathic subglottic stenosis who underwent evaluation by combined pH impedance, close to half were found to have gastroesophageal reflux disease. The majority of gastroesophageal reflux occurred while the patients were in the upright position.

The Epidemiology of Clostridium difficile Infection in Japan: A Systematic Review

Abstract

To increase understanding of the epidemiology, risks, consequences and resource utilization of Clostridium difficile infection (CDI) in Japan, a systematic literature review was undertaken of relevant publications from January 2006 to November 2017. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and methods, 55 articles met the criteria for full review. The majority (58%) of studies were from a single site, with the most recent data from 2015. The incidence, reported prevalence and recurrence rate of CDI in Japan were 0.8–4.71/10,000 patient-days, 0.3–5.5/1000 patients and 3.3–27.3%, respectively, and varied according to setting, population, CDI definition and detection method. Most C. difficile isolates associated with CDI in Japan were toxin A+B+, with a low level of C. difficile binary toxin-positive (CDT+) strains (0–6.8% reported across studies). The most common C. difficile PCR ribotypes associated with infection in Japan were smz/018, 002, 052 and 369. Data regarding the impact of CDI on length of hospital stay were limited. Reported all-cause mortality in patients with CDI ranged from 3.4 to 15.1% between 2007 and 2013. Two studies assessed risk factors for CDI recurrence, identifying malignant disease, intensive care unit hospitalization and use of proton pump inhibitors as factors increasing the risk of initial and/or recurrent CDI. No study analyzed initial CDI treatment in relation to recurrence. More comprehensive surveillance and coordinated studies are needed to map trends, understand risk factors, and recognize the extent and impact of CDI in Japanese patients.

Funding

Astellas Pharma, Inc.

Plain Language Summary

Plain language summary available for this article.

Electronic supplementary material

The online version of this article (10.1007/s40121-018-0186-1) contains supplementary material, which is available to authorized users.

Proton pump inhibitors and risk of Clostridium difficile infection: association or causation?

PURPOSE OF REVIEW

The rising burden of Clostridium difficile infection (CDI) requires urgent identification of preventable risk factors. Observational studies suggest an association between proton-pump inhibitor (PPI) use and CDI risk.

RECENT FINDINGS

Key historical literature on PPI and CDI associations is reviewed as a prelude to evaluating the plausibility of a causative association. Impactful literature from the past 18 months is examined in detail and critically appraised through the lens of the Bradford Hill Criteria for determination of causality. The PPI and CDI association has been studied extensively and is valid. Nonetheless, causality is not proven due to extensive and difficult to control confounding in observational studies of CDI patient populations with complex comorbidities.

SUMMARY

In the authors' opinion, systematic discontinuation of PPIs in patients at risk for CDI is not warranted based on current evidence. Well controlled prospective human studies are needed. Careful and repeated consideration should be given to all PPI prescriptions to avoid potential adverse effects.

[Proton pump inhibitors and kidney]

Assumed for a long time to be very well tolerated, proton pump inhibitors (PPIs) are widely prescribed for inpatients and outpatients; often beyond their validated indications. Nevertheless, many very varied side effects (pneumopathy, ischemic heart disease, dementia) have been associated with the PPIs during the last decade. Renal toxicity is mainly the occurrence of acute interstitial nephritis (AIN), related to a drug-class effect, involving cellular immunity. AINs, which occur especially in elderly patients, can be difficult to diagnose, with frequently isolated acute kidney injury, appearing with variable delay after the introduction of PPIs. Although sensitive to steroid therapy, patients frequently have an incomplete recovery of the kidney function. Very recently, the risk of chronic kidney disease (CKD) and the risk of progression of CKD among PPIs users have been well demonstrated in several large independent epidemiological studies. It is a low, but a significant side effect because of the millions of PPI prescriptions. Although further studies are needed to investigate the pathophysiological mechanisms leading the use of PPI to CKD, it is appropriate for the physicians to limit PPIs to their correct indications and to monitor renal function during these treatments.

Evidence-Based Practice in the Treatment for Antibiotic-Associated Diarrhea in the Intensive Care Unit

Unit nurses provide care to patients with serious health conditions. Often antibiotics are recommended to fight infections. Sometimes patients are on proton pump inhibitors (PPI). Antibiotics and PPIs may lead to diarrhea, causing the patient more discomfort, and possibly leading to a more serious infection. One serious infection is caused by Clostridium difficile, which causes death in some cases. About 75% of patients on antibiotics may not need antibiotics. Several studies showed less diarrhea in patients on probiotics. However, probiotics cause harm to some patients, which needs to be considered. Nurses need to ensure that antibiotic stewardship is followed.

Proton pump inhibitors therapy and risk of Clostridium difficile infection: Systematic review and meta-analysis

AIM

To perform a systematic review and meta-analysis on proton pump inhibitors (PPIs) therapy and the risk of Clostridium difficile infection (CDI).

METHODS

We conducted a systematic search of MEDLINE/PubMed and seven other databases through January 1990 to March 2017 for published studies that evaluated the association between PPIs and CDI. Adult case-control and cohort studies providing information on the association between PPI therapy and the development of CDI were included. Pooled odds ratios (ORs) estimates with 95% confidence intervals (CIs) were calculated using the random effect. Heterogeneity was assessed by I² test and Cochran’s Q statistic. Potential publication bias was evaluated via funnel plot, and quality of studies by the Newcastle-Otawa Quality Assessment Scale (NOS).

RESULTS

Fifty-six studies (40 case-control and 16 cohort) involving 356683 patients met the inclusion criteria and were analyzed. Both the overall pooled estimates and subgroup analyses showed increased risk for CDI despite substantial statistical heterogeneity among studies. Meta-analysis of all studies combined showed a significant association between PPI users and the risk of CDI (pooled OR = 1.99, CI: 1.73-2.30, P < 0.001) as compared with non-users. The association remained significant in subgroup analyses: by design-case-control (OR = 2.00, CI: 1.68-2.38, P < 0.0001), and cohort (OR = 1.98, CI: 1.51-2.59, P < 0.0001); adjusted (OR = 1.95, CI: 1.67-2.27, P < 0.0001) and unadjusted (OR = 2.02, CI: 1.41-2.91, P < 0.0001); unicenter (OR = 2.18, CI: 1.72-2.75, P < 0.0001) and multicenter (OR = 1.82, CI: 1.51-2.19, P < 0.0001); age ≥ 65 years (OR = 1.93, CI: 1.40-2.68, P < 0.0001) and < 65 years (OR = 2.06, CI: 1.11-3.81, P < 0.01). No significant differences were found in subgroup analyses (test for heterogeneity): P = 0.93 for case-control vs cohort, P = 0.85 for adjusted vs unadjusted, P = 0.24 for unicenter vs multicenter, P = 0.86 for age ≥ 65 years and < 65 years. There was significant heterogeneity across studies (I² = 85.4%, P < 0.001) as well as evidence of publication bias (funnel plot asymmetry test, P = 0.002).

CONCLUSION

This meta-analysis provides further evidence that PPI use is associated with an increased risk for development of CDI. Further high-quality, prospective studies are needed to assess whether this association is causal.

Predictors of 30-Day Mortality in Hospitalized Patients with Clostridium difficile Infection

OBJECTIVES

Clostridium difficile infection (CDI) is a significant cause of morbidity and mortality and is the most common nosocomial infection in the United States, with associated annual costs of approximately $3 billion. The epidemiology of CDI has changed with the identification of novel risk factors for incident and recurrent CDI. The aim of this study was to identify the predictors of 30-day mortality in hospitalized patients with CDI.

METHODS

We identified all of the patients diagnosed as having CDI from January 2011 to December 2014 at our university-setting hospital. Data were extracted using electronic medical records and chart review. The data of all of the patients who died within 30 days of incident CDI were compared with those who survived beyond 30 days of incident CDI. A multivariable logistic regression model was created for mortality after finding a subset of significant predictor variables by making bivariate comparisons also using logistic regression.

RESULTS

A total of 893 patients were diagnosed as having CDI during the study period. The mean age was 62 years and 49.5% were women. The mean length of hospital stay was 11.73 days. Of the 893 patients with CDI, 98 (10.97%) died within 30 days of incident CDI. CDI recurrence was noted in 76 patients (8.51%). On multivariate logistic regression analysis, peptic ulcer disease, advanced age, Charlson comorbidity index, and intensive care unit status were found to be significantly associated with 30-day mortality. There was no significant association between acid suppression and CDI mortality.

CONCLUSIONS

Advanced age, Charlson comorbidity index, intensive care unit status, and peptic ulcer disease are predictors of all-cause 30-day mortality in hospitalized patients with CDI.

Association between omeprazole use and Clostridium difficile infection among hospitalized patients: A case-control study of the Saudi population

Background: While few international studies have assessed the association between omeprazole use and the risk of Clostridium difficile infection (CDI), research into this is lacking in Saudi Arabia and the Middle East region. The aim of this study was to determine whether exposure to omeprazole is associated with the risk of Clostridium difficile infection in a sample of hospitalized Saudi patients. Methodology: A retrospective matched case–control study was conducted at the King Abdulaziz Medical City in Riyadh, Saudi Arabia, from 1 August 2010 through 31 July 2015. The analysis included a total of 200 patients: 100 CDI cases and 100 matched controls. Results: The majority (60%, 120 out of 200) of patients had received proton pump inhibitors (PPIs), and a minority (18.5%, 37 out of 200) had received omeprazole. The PPI use was insignificantly higher in CDI cases than in controls. However, the use of omeprazole was significantly higher in CDI cases compared with controls. Specifically, patients receiving omeprazole were two times more likely to develop CDI compared with controls (aOR = 2.1, 95% confidence interval (CI) = (1.007–4.437)). After adjusting for potential predictors of CDI, watery diarrhea (aOR = 59.1, 95% CI = 19.831–175.974) and abdominal pain (aOR = 7.5, 95% CI = 2.184–25.445) were found to be independent predictors of CDI. Conclusions: The data suggests that PPIs were commonly used in patients admitted to King Abdulaziz Medical City in Riyadh: six out of ten patients received PPIs. The findings support a possible association between the use of omeprazole and a high risk of CDI. To confirm causality, the link between omeprazole and CDI should be assessed in a large interventional study.

Inhibiting the proton pump: mechanisms, benefits, harms, and questions

Inhibition of the H⁺/K⁺-adenosine triphosphatase (the proton pump) is the final common mechanistic pathway in reducing gastric acid secretion pharmacologically. Proton pump inhibitors are widely used in upper gastrointestinal diseases, including gastric and duodenal ulcers, eradication of Helicobacter pylori in combination with antibiotics, gastroesophageal reflux disease, Zollinger-Ellison syndrome, eosinophilic esophagitis, and prevention of non-steroidal anti-inflammatory drug-induced peptic ulceration. Reviewing their benefits and harms in BMC Medicine, Scarpignato et al. report effectiveness in these conditions, and harms that are generally mild and uncommon (1-3 %). Serious adverse reactions, such as tubulointerstitial nephritis, are rare. However, the risks of gastric and pancreatic cancer are unclear. Drug-drug interactions can occur through effects on P glycoprotein and cytochrome P450 (CYP) isoenzymes. Several questions remain. Do all proton pump inhibitors carry the same risks of serious adverse reactions? Which individuals are most susceptible? What are the time courses of individual reactions? What monitoring strategies are best? New drugs for the same indications continue to emerge, including potassium-competitive acid blockers, inhibitors of transient lower esophageal sphincter relaxation, serotonergic agents/prokinetics, mucosal protectants, histamine H₃ receptor agonists, anti-gastrin agents, and esophageal pain modulators. Their benefit to harm balance remains to be discovered.Please see related article: https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-016-0718-z.