Spatial analysis of factors influencing choice of paediatric practice for mothers from low-income and minority populations.

AIM: Publicly reported quality data theoretically enable parents to choose higher-performing paediatric practices. However, little is known about how parents decide where to seek paediatric care. We explored the relationship between geographic factors, care quality and choice of practice to see if the decision-making process could be described in terms of a 'gravity model' of spatial data. METHODS: In the context of a randomised controlled trial, we used a geographic information system to calculate flow volume between practice locations and participants' homes, to locate subjects within a census tract, to determine distances between points and to perform exploratory mapping. Generalised linear modelling was then used to determine whether the data fit a gravity model, which is a spatial model that evaluates factors impacting travel from one set of locations to another. RESULTS: A total of 662 women and 52 paediatric practices were included in the analysis. Proximity of a practice to home was the most important factor in choosing a practice (Z = -15.01, P < 0.001). Practice size was important to a lesser extent, with larger practices more likely to be chosen (Z = 8.96, P < 0.001). A practice's performance on quality measures was associated with choice only for women who had received an intervention to increase use of quality data (Z = 2.51, P < 0.05). CONCLUSIONS: The gravity model and the concept of flow can help explain the choice of paediatric practice in a predominantly low-income, racially ethnic minority (non-White) urban population. This has important ramifications for the potential impact of publicly reported quality data.

Nephrolithiasis and Nephrocalcinosis From Topiramate Therapy in Children With Epilepsy.

INTRODUCTION: Adults treated with topiramate may develop nephrolithiasis, but its frequency in children on topiramate is unknown. Topiramate inhibits renal carbonic anhydrase, which can lead to renal tubular acidosis and hypercalciuria. We studied 40 consecutive children who initiated topiramate therapy for seizures between January 1997 and February 2003, followed for a mean of 36 months. METHODS: Serum electrolytes, urinary calcium/creatinine ratios, and renal ultrasonography were performed before topiramate and every 6 months thereafter. RESULTS: Four children developed nephrolithiasis and/or nephrocalcinosis, which resolved on discontinuation of topiramate. In 40 patients, the mean urinary calcium/creatinine ratio increased over time (P < 0.001). The mean serum bicarbonate in 40 patients decreased over time (P < 0.01). Twenty-three children had urinary calcium/creatinine ratios before topiramate. Nine children with baseline hypercalciuria (defined as urinary calcium/creatinine >0.21) were compared with the 14 children with baseline normal urinary calcium excretion. A greater increase in urinary calcium/creatinine ratios occurred in hypercalciuric children (P < 0.001) and a greater decrease in serum bicarbonate levels occurred in the hypercalciuric children (P < 0.05) compared with children with baseline normal calcium excretion. Greater urinary calcium excretion was associated with increasing doses of topiramate (P = 0.039). CONCLUSION: Our study shows that long-term therapy with topiramate in children is associated with persistent hypercalciuria and metabolic acidosis, which can lead to nephrocalcinosis and/or nephrolithiasis. All children initiating topiramate therapy should have baseline and follow-up urinary calcium/creatinine studies, serum electrolytes, and periodic renal ultrasonography, if the urinary calcium/creatinine ratio increases to a level above normal for age.

Prevalence of cranial MRI findings in girls with central precocious puberty: a systematic review and meta-analysis.

Background Some pediatric endocrinologists recommend that girls with central precocious puberty (CPP) have cranial magnetic resonance imaging (MRI) performed only if they are younger than 6 years of age. However, no practice guidelines exist. The objective of this review was to assess the frequency of intracranial lesions in girls with CPP. Content We searched six electronic databases (PubMed, Cochrane, Web of Science, SCOPUS, ProQuest, and Dissertation & Theses) from 1990 through December 2015. We included studies on girls with CPP and MRI data. Case reports, case series, studies from the same author/group with the same patient population, and studies with conditions predisposing to CPP were excluded. Two physicians independently reviewed the search results and extracted data. A random-effects model was used to obtain pooled prevalence of positive MRI's across studies. Heterogeneity among studies was evaluated with the Q-statistic. Publication bias was assessed with funnel plots and Egger's test. Pooled prevalence was computed by age group. A linear regression assessed the relationship between intracranial lesion prevalence and healthcare availability. We included 15 studies with a total of 1853 girls <8 year old evaluated for CPP. Summary The pooled prevalence from all studies was 0.09 [95% confidence interval (CI) 0.06-0.12]. There was a significant heterogeneity, indicating the appropriateness of a random effects model in computing pooled prevalence. In the few studies stratified by age group, pooled prevalence was 25% in girls <6 years vs. 3% in girls 6-8 of age. Outlook Our results support that the benefit of routine MRIs in girls with CPP older than 6 years of age without any neurological concerns is not clear-cut.

Type 3 renal tubular acidosis associated with growth hormone deficiency.

BACKGROUND: We identified two boys with type 3 renal tubular acidosis (RTA) and growth hormone deficiency and we sought to differentiate them from children with classic type 1 distal RTA. METHODS: We reviewed all children <6 years of age with RTA referred over a 13-year period and compared the growth response to alkali therapy in these two boys and in 28 children with only type 1 distal RTA. RESULTS: All children with type 1 RTA reached the 5th percentile or higher on CDC growth charts within 2 years of alkali therapy. Their mean height standard deviation score (SDS) improved from -1.4 to -0.6 SDS and their mean mid-parental height (MPH) SDS improved from -0.6 to 0 SDS after 2 years. In contrast, the boys with growth hormone deficiency had a height SDS of -1.4 and -2.4 SDS after 2 years of alkali and the MPH SDS were both -2.6 SDS after 2 years of alkali therapy. Growth hormone therapy accelerated their growth to normal levels and led to long-term correction of RTA. CONCLUSIONS: A child with type 1 RTA whose height response after 2 years of alkali therapy is inadequate should undergo provocative growth hormone testing.

Long-term outcomes of elders discharged on antipsychotics.

BACKGROUND: Despite limited evidence of efficacy, antipsychotics (APs) are commonly used to treat delirium. There has been little research on the long-term outcomes of patients who are started on APs in the hospital. METHODS: Using a previously described retrospective cohort of 300 elders (≥65 years old) who were newly prescribed APs while hospitalized between October 1, 2012 and September 31, 2013, we examined the 1-year outcomes of patients alive at the time of discharge. We examined number of readmissions, reasons for readmission, duration of AP therapy, use of other sedating medications, and incidence of readmission. We used the National Death Index to describe 1-year mortality and then created a multivariable model to identify predictors of 1-year mortality. RESULTS: The 260 patients discharged alive from their index admissions had a 1-year mortality rate of 29% (75/260). Of the 146/260 patients discharged on APs, 60 (41%) patients experienced at least 1 readmission. At the time of first readmission, 65% of patients were still taking the same APs on which they had been discharged. Eighteen patients received new APs during the readmission hospitalizations. Predictors of death at 1 year included discharge to postacute facilities after index admission (odds ratio [OR]: 2.28; 95% confidence interval [CI]: 1.10-4.73, P = 0.03) and QT interval prolongation >500 ms during index admission (OR: 3.41; 95% CI: 1.34-8.67, P = 0.01). CONCLUSIONS: Initiating an AP in the hospital is likely to result in long-term use of these medications. Patients who received an AP during a hospitalization were at high risk of death in the following year. Journal of Hospital Medicine 2016;11:550-555. © 2016 Society of Hospital Medicine.

Validity of STONE scores in younger patients presenting with suspected uncomplicated renal colic.

OBJECTIVES: Recent studies have cast doubt on the routine need for emergent computed tomographic (CT) scan in patients with suspected renal colic. A clinical prediction rule, the STONE score, was recently published with the goal of helping clinicians predict obstructive kidney stones in noninfected flank pain patients before CT scan. We sought to examine the validity of this score in younger, noninfected flank pain patients. METHODS: A secondary analysis of a retrospective cohort study was performed to determine the validity of STONE scores for predicting the outcome of obstructive kidney stone in patients age 18 to 50 years presenting with flank pain suggestive of uncomplicated ureterolithiasis. Validity was measured by calculation of the area under the curve of the receiver operating characteristic curve. Sensitivity, specificity, negative predictive value, positive predictive value, and ±likelihood ratios were calculated for various cutoff values. RESULTS: Of 134 patients who met inclusion criteria, 56.7% were female, average age was 37 years, and 52% had an obstructing kidney stone by CT scan. The receiver operating characteristic curve for the STONE score had an area under the curve of 0.87 (95% confidence interval, 0.80-0.93) and indicated that a cutoff of greater than or equal to 8 would have a sensitivity of 78.6%, specificity of 84.4%, negative predictive value of 78.3%, positive predictive value of 84.6%, and +likelihood ratio of 4.9. CONCLUSIONS: This analysis suggests that the STONE score is valid in younger populations. It can aid in determining pretest probability and help inform conversations about the likelihood of the diagnosis of renal colic before imaging, which may be useful for decision making.

Young patients with suspected uncomplicated renal colic are unlikely to have dangerous alternative diagnoses or need emergent intervention.

INTRODUCTION: In the United States there is debate regarding the appropriate first test for new-onset renal colic, with non-contrast helical computed tomography (CT) receiving the highest ratings from both Agency for Healthcare Research and Quality and the American Urological Association. This is based not only on its accuracy for the diagnosis of renal colic, but also its ability to diagnose other surgical emergencies, which have been thought to occur in 10-15% of patients with suspected renal colic, based on previous studies. In younger patients, it may be reasonable to attempt to avoid immediate CT if concern for dangerous alternative diagnosis is low, based on the risks of radiation from CTs, and particularly in light of evidence that patients with renal colic have a very high likelihood of having multiple CTs in their lifetimes. The objective is to determine the proportion of patients with a dangerous alternative diagnosis in adult patients age 50 and under presenting with uncomplicated (non-infected) suspected renal colic, and also to determine what proportion of these patients undergo emergent urologic intervention. METHODS: Retrospective chart review of 12 months of patients age 18-50 presenting with "flank pain," excluding patients with end stage renal disease, urinary tract infection, pregnancy and trauma. Dangerous alternative diagnosis was determined by CT. RESULTS: Two hundred and ninety-one patients met inclusion criteria. One hundred and fifteen patients had renal protocol CTs, and zero alternative emergent or urgent diagnoses were identified (one-sided 95% CI [0-2.7%]). Of the 291 encounters, there were 7 urologic procedures performed upon first admission (2.4%, 95% CI [1.0-4.9%]). The prevalence of kidney stone by final diagnosis was 58.8%. CONCLUSION: This small sample suggests that in younger patients with uncomplicated renal colic, the benefit of immediate CT for suspected renal colic should be questioned. Further studies are needed to determine which patients benefit from immediate CT for suspected renal colic, and which patients could undergo alternate imaging such as ultrasound.

Improvement in headaches with continuous positive airway pressure for obstructive sleep apnea: a retrospective analysis.

OBJECTIVE: We aimed to identify clinical features in patients with severe headaches that predicted obstructive sleep apnea (OSA) and determine clinical and sleep study characteristics that predicted headache improvement with continuous positive airway pressure (CPAP). BACKGROUND: Many patients with headaches complain of sleep symptoms and have OSA. There is often improvement of headaches with CPAP treatment. METHODS: We conducted a retrospective chart review of all patients referred to adult neurology clinic for headaches and sent for polysomnography between January 2008 and December 2009. Follow-up ranged from 18 to 42 months. RESULTS: Eighty-two headache patients (70 females, 12 males) were studied. Mean age was 45±13 years (females 45±13, males 43±11) and mean body mass index was 32±9. Headache types included 17% chronic migraine without aura, 22% episodic migraine without aura, 32% migraine with aura, 21% tension-type headache, 6% chronic post-traumatic headache, 11% medication overuse headache, and 7% other types. All patients were receiving standard treatment for their headaches by their neurologist. Fifty-two patients (63%) had OSA. Increasing age, female gender, and chronic migraine without aura were predictive of OSA. Of the patients with OSA, 33 (63%) used CPAP and 27 (82%) were adherent to CPAP. Headache improvement was reported by 40 patients (49%) due to either standard medical therapy or CPAP. Patients with OSA who were CPAP adherent (21/27) were more likely to have improvement in headaches than patients intolerant of CPAP (2/6), those that did not try CPAP (8/19), and those who did not have OSA (16/30) (P=.045). Of the 33 patients who used CPAP, 13 reported improvement in headaches specifically due to CPAP therapy and 10 additional patients noted benefit in sleep symptoms. The presence of witnessed apneas (P=.045) and male gender (P=.021) predicted improvement in headaches due to CPAP. CONCLUSIONS: Headache patients should be evaluated for the presence of OSA. Treating OSA improves headaches in some patients.

Profiling of ABC transporters ABCB5, ABCF2 and nestin-positive stem cells in nevi, in situ and invasive melanoma.

Distinct ABCB5 forms and ABCF2, members of the ATP-binding cassette (ABC) superfamily of transporters, are normally expressed in various tissues and cells, and enhanced expression of both has been demonstrated in select cancers. In melanoma cell lines, gene expression profiling of ABC transporters has revealed enhanced expression of melanocyte-specific ABCB5 and ABCF2 proteins. Given this, our primary aim was to ascertain immunohistochemical expression of the ABC transporters ABCB5 and ABCF2 and, the stem cell marker, nestin in a spectrum of benign and malignant nevomelanocytic proliferations, including nevi (n=30), in situ (n=31) and invasive (n=24) primary cutaneous melanomas to assess their role in the stepwise development of malignancy. In addition, their expression was compared with established melanoma prognosticators to ascertain their utility as independent prognosticators. A semiquantitative scoring system was utilized by deriving a cumulative score (based on percentage positivity cells and intensity of expression) and statistical analyses was carried out using analysis of variance with linear contrasts. Mean cumulative score in nevi, in situ and invasive melanoma were as follows: 3.8, 4.4 and 5.3 for ABCB5, respectively (P<0.005 for all), and 4.6, 4.6 and 5.3 for nestin, respectively (P=not significant for all). No appreciable expression of ABCF2 was noted in any of the groups. While ulcerated lesions of melanoma demonstrated lower levels of expression of ABCB5 and nestin than non-ulcerated lesions, and nestin expression was lower in lesions with mitoses >1, after controlling for the presence of ulceration and mitotic activity, the expression of both proteins did not significantly correlate with known melanoma prognosticators. The gradual increase in the expression of ABCB5 from benign nevus to in situ to invasive melanoma suggests that it plays a role in melanomagenesis. On the basis of our findings, a prospective study with follow-up data is required to ascertain the utility of ABCB5 as a therapeutic target.

Improvement in glycemic control following a diabetes education intervention is associated with change in diabetes distress but not change in depressive symptoms.

In diabetes patients, depression is correlated with diabetes-specific emotional distress, and observational studies have suggested that diabetes distress may have a greater impact on diabetes outcomes than depression itself. To examine the relative effects of change in depressive symptoms and change in diabetes distress on change in glycemic control, we conducted a diabetes self-management education intervention in 234 type 2 diabetes (T2DM) patients, and measured glycemic control (HbA1c), depressive symptoms (CES-D), and diabetes distress (PAID) at baseline and 6 months. In multiple linear regression, change in depressive symptoms was not associated with change in HbA1c (P=0.23). Change in diabetes distress was significantly associated with change in HbA1c (P<0.01), such that a 10-point decrease in diabetes distress (which corresponds to the average change in distress in this study population) was associated with a 0.25% reduction in HbA1c. Change in diabetes distress, and not change in depressive symptoms, was associated with both short- and long-term change in glycemic control for patients with poorly controlled T2DM.

Primary hyperparathyroidism in the underinsured: a study of 493 patients.

BACKGROUND: Disparities may exist in the care of patients with primary hyperparathyroidism (HPT). This study examines the presentation and outcomes of underinsured patients undergoing parathyroidectomy. METHODS: We divided 493 HPT patients who underwent initial parathyroidectomy from 2000 to 2008 at a single institution into 2 groups: underinsured patients (group 1; n = 94) evaluated and treated at a county hospital, and patients with insurance (group 2; n = 399). Univariate and multivariate analysis adjusting for race and ethnicity were conducted to determine the association of being underinsured with several clinical variables. RESULTS: More patients in group 1 compared with group 2 were of black or Hispanic background (92% vs. 44%; P < .0001). Group 1 patients had higher mean preoperative serum calcium and PTH levels: 12.1 vs. 11.8 mg/dL (P = .009) and 263 vs. 198 pg/mL (P = .03), respectively. Seven group 1 (7.4%) and 7 group 2 (1.8%) patients presented with hypercalcemic crisis (P = .003). On multivariate analysis, underinsurance was associated with higher serum calcium levels (P = .011) and hypercalcemic crisis at presentation (odds ratio, 5.59; 95% confidence interval, 1.45-21.51; P = .012). Follow-up was shorter in group 1 patients (15 vs. 24 months; P < .001) and postoperative PTH levels were higher (76 vs. 48 pg/mL; P < .001). Other perioperative data were not different between the groups. CONCLUSION: Underinsured patients with HPT may present with higher serum calcium and PTH levels, are more likely to have hypercalcemic crisis, and less likely to return for follow-up. Underfunded health insurance coverage may account for differences seen in this study.

Residents-as-teachers: implementing a toolkit in morning report to redefine resident roles.

BACKGROUND: Morning report was initially created to meet service needs. PURPOSE: The objective was to improve morning report through a toolkit combining principles of learning theory with resident teaching. METHODS: The toolkit consists of three parts: a guideline describing expectations, a worksheet outlining teaching plans, and a feedback form facilitating post-presentation feedback. In 2009-2010, internal medicine residents met with a chief resident before their presentations to refine teaching plans. The chief resident then supported the presenter in achieving their objectives and provided post-presentation feedback. Residents were surveyed before and 6 months after the intervention. Mean scores were compared using an unpaired t test. RESULTS: Residents' ratings improved in the following domains: understanding expectations (3.10 vs. 4.02, p = .0003), presentation organization (3.50 vs. 4.25, p = .005), and creating and accomplishing learning objectives (3.31 vs. 4.00, p = .002). Residents commented positively on the improved presentations. CONCLUSIONS: This toolkit, based on educational principles, improved morning report presentations.

Geographic distribution of community-acquired methicillin-resistant Staphylococcus aureus soft tissue infections.

PURPOSE: The goal of this study is to look at the geographic growth patterns of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) infections in our local region and to determine if specific geographic areas are at increased risk. METHODS: After Institution Review Board approval (132603-3), a retrospective chart review was conducted of 614 patients who underwent incision and drainage of an abscess by a single pediatric surgical practice from January 2004 to December 2008. In addition, previously published data from 195 patients who underwent incision and drainage of an abscess from January 2000 to December 2003 were reviewed. RESULTS: The most commonly cultured organism found in the pediatric population undergoing incision and drainage was S aureus (n = 388), of which 258 (66%) were methicillin resistant. This is a 21% increase from the rate of MRSA cultures identified from 2000 to 2003. Geographic information system space-time analysis showed that a cluster of 14 MRSA cases was located within a 1.44-km radius between 2000 and 2003, and 5 separate clusters of more than 20 MRSA infection cases each were identified in 3 separate cities over the 8-year time span using geographic information system spatial analysis (P value = .001). CONCLUSION: Methicillin-resistant S aureus has now become the most prevalent organism isolated from cultures of community-acquired abscesses requiring incision and drainage in the pediatric population in our local region. Significant clustering of MRSA infections has appeared in several different cities within our geographic region.

Rectal biopsies obtained with jumbo biopsy forceps in the evaluation of Hirschsprung disease.

BACKGROUND AND AIM: Refractory constipation is an extremely common problem in infants and children. The diagnostic suspicion of Hirschsprung disease often arises in this clinical setting. Diagnosing Hirschsprung disease can be difficult; however, excluding the diagnosis is much easier, only requiring the demonstration of ganglion cells in the distal rectum. The most common method for obtaining tissue from the rectum involves a blind suction biopsy. This technique has been complicated by serious adverse events, equipment malfunction, and inadequate specimens. Our goal was to evaluate the adequacy of specimens obtained with a flexible endoscope and jumbo biopsy forceps to rule out Hirschsprung disease in the child outside the newborn period. PATIENTS AND METHODS: We retrospectively reviewed 668 rectal biopsies taken during 167 endoscopies on 156 patients being evaluated for Hirschsprung disease from 2001 to 2008 at the Baystate Medical Center Children's Hospital. Four biopsies were taken from each patient approximately 2.5 cm from the anal verge. Biopsies were obtained using a flexible endoscope and jumbo biopsy forceps. During the first 6 years the Olympus FB-50U-1 large cup fenestrated biopsy forceps was used. During the last 2 years the Boston Scientific Radial Jaw 4 Jumbo biopsy forceps was used instead. RESULTS: The Boston Scientific Radial Jaw 4 Jumbo biopsy forceps yielded adequate specimens 93% of the time, which surpassed most published results of other techniques. There were no complications reported. CONCLUSIONS: Obtaining rectal biopsies with a flexible endoscope and jumbo biopsy forceps is a safe and effective means to rule out the diagnosis of Hirschsprung disease in children.

Geography and travel distance impact emergency department visits.

BACKGROUND: Little has been written about the geographic basis of emergency department (ED) visits. OBJECTIVE: The objective of this study is to describe the impact of geography on ED visits. METHODS: A retrospective analysis was conducted of ED visits during a 1-year period at a single institution using spatial interaction analysis that models the pattern of flow between a series of origins (census block groups) and a destination (ED). Patients were assigned to census block groups based upon their verified home address. The study hospital is the only Level I trauma, pediatric, and tertiary referral center in the area. There are 11 other hospitals with EDs within a 40-mile radius. Each patient visit within this radius, including repeat visits, was included. Patients with an invalid home address, a post office box address, or those who lived outside a 40-mile radius were excluded. ED visits per 100 population were calculated for each census block group. RESULTS: There were 98,584 (95%) visits by 63,524 patients that met study inclusion criteria. Visit rates decreased with increasing distance from the ED (p < 0.0001). Nineteen percent of patients lived within 2 miles, 48% within 4 miles, and 92% within 12 miles of the ED. The Connecticut border, 7 miles south of the ED (p < 0.0001), the Connecticut River, 1 mile west of the ED (p < 0.0001), and the presence of a competing ED within 1 mile (p < 0.0001) negatively impacted block group ED visit rates. Travel distance was related to the percentage of visits that were high acuity (p < 0.0001), daytime (p < 0.01), or resulted in admission (p < 0.0001). CONCLUSIONS: Geography and travel distance significantly impact ED visits.

Motivational interviewing delivered by diabetes educators: does it improve blood glucose control among poorly controlled type 2 diabetes patients?

AIM: To determine whether glycemic control is improved when motivational interviewing (MI), a patient-centered behavior change strategy, is used with diabetes self management education (DSME) as compared to DSME alone. METHODS: poorly controlled type 2 diabetes (T2DM) patients (n=234) were randomized into 4 groups: MI+DSME or DSME alone, with or without use of a computerized summary of patient self management barriers. We compared HbA1c changes between groups at 6 months and investigated mediators of HbA1c change. RESULTS: study patients attended the majority of the four intervention visits (mean 3.4), but drop-out rate was high at follow-up research visits (35%). Multiple regression showed that groups receiving MI had a mean change in HbA1c that was significantly lower (less improved) than those not receiving MI (t=2.10; p=0.037). Mediators of HbA1c change for the total group were diabetes self-care behaviors and diabetes distress; no between-group differences were found. CONCLUSIONS: DSME improved blood glucose control, underlining its benefit for T2DM management. However, MI+DSME was less effective than DSME alone. Overall, weak support was found for the clinical utility of MI in the management of T2DM delivered by diabetes educators.

Using GIS for spatial analysis of rectal lesions in the human body.

BACKGROUND: Geographic Information Systems (GIS) have been used in a wide variety of applications to integrate data and explore the spatial relationship of geographic features. Traditionally this has referred to features on the surface of the earth. However, it is possible to apply GIS in medicine, at the scale of the human body, to visualize and analyze anatomic and clinical features. In the present study we used GIS to examine the findings of transanal endoscopic microsurgery (TEM), a minimally-invasive procedure to locate and remove both benign and cancerous lesions of the rectum. Our purpose was to determine whether anatomic features of the human rectum and clinical findings at the time of surgery could be rendered in a GIS and spatially analyzed for their relationship to clinical outcomes. RESULTS: Maps of rectal topology were developed in two and three dimensions. These maps highlight anatomic features of the rectum and the location of lesions found on TEM. Spatial analysis demonstrated a significant relationship between anatomic location of the lesion and procedural failure. CONCLUSION: This study demonstrates the feasibility of rendering anatomical locations and clinical events in a GIS and its value in clinical research. This allows the visualization and spatial analysis of clinical and pathologic features, increasing our awareness of the relationship between anatomic features and clinical outcomes as well as enhancing our understanding and management of this disease process.

Evaluation of the IRMA TRUpoint and i-STAT creatinine assays.

BACKGROUND: The i-STAT (Abbott Diagnostics, East Windsor, NJ) and IRMA TRUpoint (ITC, Edison, NJ) POCT analyzers were evaluated in an oncology center. METHODS: Precision and agreement with our core laboratory creatinine was judged by comparison of 50 consecutive chemotherapy patient results against the Roche rate-blanked Jaffe and enzymatic creatinine methods. Glomerular filtration rate (GFR) was estimated using the Cockroft-Gault (CG) calculation and Modification of Diet in Renal Disease Study (MDRD) equation. RESULTS: Precision varied from 1% (enzymatic)-6.1% (TRUpoint). Correlation was good (r>0.9948) with slopes within 5% of the Jaffe and enzymatic methods. Intercepts were <15.9 micromol/l (<0.18 mg/dl), and statistically significant bias (p<0.0025) was noted between the mean of patient specimens for i-STAT correlations to both the Jaffe and enzymatic laboratory creatinine methods. There was statistically significant concordance of estimated GFR between all methods, however, the agreement of estimated GFR to either the Jaffe or enzymatic creatinine laboratory methods was better for the TRUpoint (by either MDRD or CG estimation) and i-STAT (by MDRD equation) (Kappa>0.60) than the i-STAT (by CG estimation) (Kappa=0.41-0.60). CONCLUSION: Small biases in the calibration of analytical creatinine methods can lead to differences in clinical concordance using estimated GFR. Selecting an optimal POCT method depends on the institution's current creatinine method and tolerance for analytical performance and clinical concordance.