Thomas M. English

Comparison of the Modification of Diet in Renal Disease and Cockcroft-Gault Equations for Antimicrobial Dosage Adjustments

Background: Direct measurement of glomerular filtration rate (GFR) is considered to be the most accurate method of assessing kidney function, albeit difficult and costly. With the derivation of the Modification of Diet in Renal Disease (MDRD) equation to estimate GFR in patients with chronic kidney disease, questions exist as to whether this method should be preferred over the Cockcroft–Gault (CG) equation when making dosage adjustments for renally eliminated antimicrobials. Objective: To determine whether a difference exists when making antimicrobial dosage adjustments in patients with chronic kidney disease based on estimation of GFR using the MDRD and CG equations. Methods: We conducted an observational analysis of 409 patients with chronic kidney disease who were admitted to a tertiary care facility with an inpatient dialysis center and nephrology unit. GFR was calculated using both the 4- or 6-variable MDRD equation and the CG equation and compared using correlation and Bland–Altman methodology. Dosage discordance rates of the selected antimicrobials were determined on the basis of manufacturer renal dose recommendations. Results: Average ± SD GFR for all patients using the CG equation was 34.8 ± 12 mL/min and, using the MDRD equation, was 40.2 ± 12 mL/min (absolute mean difference 5.40; 95% CI 4.66 to 6.15; p < 0.001). The correlation coefficient between the 2 estimations, among all patients, was excellent (r=0.80). The Bland–Altman plot yielded limits of agreement of -9.8 and 20.6; thus, the MDRD estimation may range from 9.8 mL/min below to 20.6 mL/min above the CG estimation for 95% of the cases. A discordance rate of 21–37% (p < 0.001) existed among the recommended dosing adjustments of the selected antimicrobials. Conclusions: This analysis demonstrated statistically significant differences between the CG and MDRD equations, resulting in different dosing recommendations in 21–37% of patients. The clinical significance of these differences is uncertain in the absence of data regarding clinical outcomes that would result from the use of the discordant doses.

Access to Care and Use of the Internet to Search for Health Information: Results From the US National Health Interview Survey

Background The insurance mandate of the Affordable Care Act has increased the number of people with health coverage in the United States. There is speculation that this increase in the number of insured could make accessing health care services more difficult. Those who are unable to access care in a timely manner may use the Internet to search for information needed to answer their health questions. Objective The aim was to determine whether difficulty accessing health care services for reasons unrelated to insurance coverage is associated with increased use of the Internet to obtain health information. Methods Survey data from 32,139 adults in the 2011 National Health Interview Study (NHIS) were used in this study. The exposure for this analysis was reporting difficulty accessing health care services or delaying getting care for a reason unrelated to insurance status. To define this exposure, we examined 8 questions that asked whether different access problems occurred during the previous 12 months. The outcome for this analysis, health information technology (HIT) use, was captured by examining 2 questions that asked survey respondents if they used an online health chat room or searched the Internet to obtain health information in the previous 12 months. Several multinomial logistic regressions estimating the odds of using HIT for each reported access difficulty were conducted to accomplish the study objective. Results Of a survey population of 32,139 adults, more than 15.90% (n=5109) reported experiencing at least one access to care barrier, whereas 3.63% (1168/32,139) reported using online health chat rooms and 43.55% (13,997/32,139) reported searching the Internet for health information. Adults who reported difficulty accessing health care services for reasons unrelated to their health insurance coverage had greater odds of using the Internet to obtain health information. Those who reported delaying getting care because they could not get an appointment soon enough (OR 2.2, 95% CI 1.9-2.5), were told the doctor would not accept them as a new patient or accept their insurance (OR 2.1, 95% CI 1.7-2.5 and OR 2.1, 95% CI 1.7-2.5, respectively), or because the doctor’s office was not open when they could go (OR 2.2, 95% CI 1.9-2.7) had more than twice the odds of using the Internet to obtain health information compared to those who did not report such access difficulties. Conclusions People experiencing trouble accessing health care services for reasons unrelated to their insurance status are more likely to report using the Internet to obtain health information. Improving the accuracy and reliability of health information resources that are publicly available online could help those who are searching for information due to trouble accessing health care services.

Assessment of Vancomycin Dosing and Subsequent Serum Concentrations in Pediatric Patients

Background Because of concerns regarding increasing microbial resistance to vancomycin, adult treatment guidelines recommend higher trough concentrations based on the type of infectious process. Although these recommendations are not specific to pediatrics, the principles can be extrapolated. Desired higher trough serum concentrations will require escalated dosages of vancomycin in children. Objective: To evaluate current dosing regimens and subsequent trough serum concentrations of vancomycin in children, compare these to reference recommended dosages and guidelines, and predict a dosing equation to achieve desired serum concentrations. Methods: Pharmacokinetic parameters of children in a community teaching hospital who were prescribed vancomycin from January 2005 to May 2010 were evaluated in this retrospective chart review. Vancomycin dosing and subsequent serum concentrations were analyzed. Therapeutic serum concentrations were evaluated and compared to vancomycin prescribing and monitoring guidelines by year. Results: Four hundred thirty-five trough serum concentrations determined in 295 patients were analyzed. The average dosages, when evaluated by year, were 48 mg/kg/day (2005-2008) and 59 mg/kg/day (2009-2010). Using trough concentration recommendations of 5-15 mg/L, vancomycin regimens provided therapeutic trough concentrations 78% of the time from 2005 to 2008. Using 10-20 mg/L as the trough recommendations in 2009-2010, only 49% of serum concentrations reached a therapeutic level. Based on our predictive equation for children aged 1 month-18 years with normal renal function, a vancomycin dosage of 70 mg/kg/day is required to provide trough serum concentrations of 10 mg/L; a dosage of 85 mg/kg/day is required to provide trough serum concentrations of 15 mg/L. Conclusions: Our institution was primarily using vancomycin dosing regimens that were recommended in pediatric references (40-60 mg/kg/day), which resulted in subtherapeutic serum concentrations in our population based on new monitoring recommendations. Considering that the currently desired therapeutic trough concentrations of vancomycin are 10-20 mg/L, the total daily dosage should be increased.

A Systematic Review of Electronic Portal Usage Among Patients with Diabetes

The objectives of this review were (1) to examine characteristics associated with enrollment and utilization of portals among patients with diabetes and (2) to identify barriers and facilitators of electronic patient portal enrollment and utilization. PubMed and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) were systematically searched for papers reporting original research using quantitative or qualitative methods on characteristics, barriers, and facilitators associated with portal enrollment and utilization among patients with diabetes in the United States. The search was limited to articles published between February 1, 2005 (the date of the national symposium on personal health records) and January 1, 2014. Sixteen articles were identified. Of these, nine were quantitative, three were qualitative, and four used mixed-methods. Several demographic characteristics, having better-controlled diabetes, and providers who engaged in and encouraged portal use were associated with increased portal enrollment and utilization. Barriers to portal enrollment included a lack of patient (1) capacity, (2) desire, and (3) awareness of portal/portal functions. Barriers to portal utilization included (1) patient capacity, (2) lack of provider and patient buy-in to portal benefits, and (3) negative patient experiences using portals. Facilitators of portal enrollment and utilization were providers and family members recommending and engaging in portal use. Improved usability, increased access, educating patients how to use and benefit from portals, and greater endorsement by providers and family members might increase portal enrollment and utilization. As more providers and hospitals offer portals, addressing barriers and leveraging facilitators may help patients with diabetes achieve potential benefits.

Evaluation of the Chronic Kidney Disease Epidemiology Collaboration Equation for Dosing Antimicrobials

Background: Since the derivation of the Modification of Diet in Renal Disease (MORD) equation for estimating glomerular filtration rate (GFR), investigators determined that it cannot be used for drug dosing. In 2009, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) derived an equation that was more accurate than the MORD estimation of GFR. Therefore, questions exist about which method should be preferred in making dosage adjustments for renally eliminated antimicrobials. Objective: To determine whether a difference exists when making antimicrobial dosage adjustments in patients with CKD based on estimation of GFR using the CKD-EPI and Cockcroft-Gault equations. Methods: A database of 409 patients with CKD admitted to a tertiary care facility was used. GFR was calculated using both the CKD-EPI equation(s) and the Cockcroft-Gault equation and compared using correlation and Bland-Altman methodology. Dosage discordance rates of antimicrobials were determined. Results: Average GFRs for all patients using the Cockcroft-Gault and CKD-EPI equations were 34.8 ± 12 mL/rnin and 39.9 ± 13 mL/min, respectively (5.09 [95% CI 4.60 to 5.59]; p < 0.001). The correlation coefficient between the 2 estimations was high (r = 0.91). The Bland-Altman plot yielded limits of agreement of 15.3 and -5.1; thus, the CKD-EPI estimation may range from 5.1 mL/min below to 15.3 mL/min above the Cockcroft-Gault estimation for 95% of the cases. A discordance rate of 15–25% existed among the recommended dosing adjustments of the selected antimicrobials when comparing the Ccckcroft-Gault and CKD-EPI estimations. Conclusions: Though this study did not determine which equation should be selected to dose adjust antimicrobials, it demonstrated statistically significant differences between the Cockcroft-Gault and CKD-EPI equations. The clinical significance of these differences is uncertain in the absence of data assessing clinical outcomes that result from the use of the discordant doses. Clinical judgment should be employed when making renal dosage adjustments of antimicrobials.

Closing the Feedback Loop: An Interactive Voice Response System to Provide Follow-up and Feedback in Primary Care Settings

In primary care settings, follow-up regarding the outcome of acute outpatient visits is largely absent. We sought to develop an automated interactive voice response system (IVRS) for patient follow-up with feedback to providers capable of interfacing with multiple pre-existing electronic medical records (EMRs). A system was designed to extract data from EMRs, integrate with the IVRS, call patients for follow-up, and provide a feedback report to providers. Challenges during the development process were analyzed and summarized. The components of the technological solution and details of its implementation are reported. Lessons learned include: (1) Modular utilization of system components is often needed to adapt to specific clinic workflow and patient population needs (2) Understanding the local telephony environment greatly impacts development and is critical to success, and (3) Ample time for development of the IVRS questionnaire (mapping all branching paths) and speech recognition tuning (sensitivity, use of barge-in tuning, use of “known voice”) is needed. With proper attention to design and development, modular follow-up and feedback systems can be integrated into existing EMR systems providing the benefits of IVRS follow-up to patients and providers across diverse practice settings.

Caregivers’ Baseline Understanding and Expectations of Antibiotic Use for Their Children

Although there is evidence that oral antibiotic prescriptions for children have decreased since the 1990s, antibiotic resistance continues to be a problem. This study evaluated the caregivers’ understanding of antibiotic use for their children and identified demographic characteristics that may contribute to inappropriate antibiotic-seeking behavior. Caregivers were asked how often the child should receive antibiotics for common medical conditions and about factors to improve patient compliance. This study found that caregivers overexpected antibiotic use with upper respiratory infection, ear infection, and pneumonia. Caretakers with lower incomes and on Medicaid comprised the higher percentage of overusers. The most important factors to improve patient compliance were explanation of the name and indication for antibiotic use. This study showed that demographic variables play a role in caregivers’ expectations of antibiotic use. Effective communication of physicians with caregivers on antibiotic use can be an important strategy to improve patient compliance.

Crave-Out: A Distraction/Motivation Mobile Game to Assist in Smoking Cessation

Background Smoking is still the number one preventable cause of death. Cravings—an intense desire or longing for a cigarette—are a major contributor to quit attempt failure. New tools to help smokers’ manage their cravings are needed. Objective To present a case study of the development process and testing of a distraction/motivation game (Crave-Out) to help manage cravings. Methods We used a phased approach: in Phase 1 (alpha testing), we tested and refined the game concept, using a Web-based prototype. In Phase 2 (beta testing), we evaluated the distraction/motivation potential of the mobile game prototype, using a prepost design. After varying duration of abstinence, smokers completed the Questionnaire of Smoking Urge-Brief (QSU-Brief) measurement before and after playing Crave-Out. Paired t tests were used to compare pregame and postgame QSU-Brief levels. To test dissemination potential, we released the game on the Apple iTunes App Store and tracked downloads between December 22, 2011, and May 5, 2014. Results Our concept refinement resulted in a multilevel, pattern memory challenge game, with each level increasing in difficulty. Smokers could play the game as long as they wanted. At the end of each level, smokers were provided clear goals for the next level and rewards (positive reinforcement using motivational tokens that represented a benefit of quitting smoking). Negative reinforcement was removed in alpha testing as smokers felt it reminded them of smoking. Measurement of QSU-Brief (N=30) resulted in a pregame mean of 3.24 (SD 1.65) and postgame mean of 2.99 (SD 1.40) with an overall decrease of 0.25 in cravings (not statistically significant). In a subset analysis, the QSU-Brief decrease was significant for smokers abstinent for more than 48 hours (N=5) with a pregame mean of 2.84 (SD 1.16) and a postgame mean of 2.0 (SD 0.94; change=0.84; P =.03). Between December 22, 2011, and May 29, 2014, the game was downloaded 3372 times from the App-Store, with 1526 smokers visiting the online resource www.decide2quit.org linked to the game. Conclusions Overall, playing the game resulted in small, but nonsignificant decreases in cravings, with changes greater for those had already quit for more than 48 hours. Lessons learned can inform further development. Future research could incorporate mHealth games in multicomponent cessation interventions. Trial Registration Clinicaltrials.gov NCT00797628; https://clinicaltrials.gov/ct2/show/NCT00797628 (Archived by WebCite at http://www.webcitation.org/6hbJr6LWG)

Vancomycin Combined With Clindamycin for the Treatment of Acute Bacterial Skin and Skin-Structure Infections

BACKGROUND Acute bacterial skin and skin-structure infections (ABSSSIs) are common causes of hospital admissions. These infections are often caused by methicillin-resistant Staphylococcus aureus; therefore, vancomycin remains a commonly used therapy. The purpose of this study was to compare hospital length of stay (LOS) in patients treated with vancomycin monotherapy vs combination therapy with clindamycin for ABSSSIs. METHODS This was a retrospective analysis of 269 patients admitted with ABSSSIs to a 941-bed hospital in northern Alabama. Patients who received either vancomycin monotherapy or vancomycin in combination with clindamycin were included. The primary outcome was hospital LOS; secondary outcomes included 90-day readmission rate and the impact of the following on the primary outcome: organisms cultured, presence of abscess, incision and debridement (I&D), failure of a trial of outpatient antibiotics, and presence of diabetes. RESULTS Hospital LOS was similar between groups when evaluating all ABSSSIs (3.7 ± 1.5 days vs 4.0 ± 2.0 days, P = .192, combination and monotherapy, respectively). In patients with abscesses, combination therapy was significantly associated with decreased LOS by 18.2% compared with monotherapy (95% confidence interval [CI], 0.818 [.679 to .985]; P = .034). Among the entire population, significantly fewer patients in the combination group were readmitted within 90 days (5.3% vs 15.3%; P = .006; odds ratio [OR], 3.2; 95% CI [1.35 to 7.66]). The 90-day readmission rates were significantly lower among patients with abscesses as well (2.0% vs 24.3%; P = .0001; OR, 14.6; 95% CI [2.98 to 71.37]). CONCLUSIONS Combination therapy with vancomycin and clindamycin was associated with decreased hospital LOS for patients with an abscess. The 90-day hospital readmission rates for those with ABSSSIs may be reduced when combination therapy is utilized. A larger, prospective, multicentered study is needed to validate these findings.

Federated Aggregate Cohort Estimator (FACE)

Cross-institutional data sharing for cohort discovery is critical to enabling future research. While particularly useful in rare diseases, the ability to target enrollment and to determine if an institution has a sufficient number of patients is valuable in all research, particularly in the initiation of projects and collaborations. An optimal technology solution would work with any source database with minimal resource investment for deployment and would meet all necessary security and confidentiality requirements of participating organizations. We describe a platform-neutral reference implementation to meet these requirements: the Federated Aggregate Cohort Estimator (FACE). FACE was developed and implemented through a collaboration of The University of Alabama at Birmingham (UAB), The Ohio State University (OSU), the University of Massachusetts Medical School (UMMS), and the Denver Health and Hospital Authority (DHHA) a clinical affiliate of the Colorado Clinical and Translational Sciences Institute. The reference implementation of FACE federated diverse SQL data sources and an i2b2 instance to estimate combined research subject availability from three institutions. It used easily-deployed virtual machines and addressed privacy and security concerns for data sharing.