Matched Case-control Analysis Research Articles

Systemic Candidiasis in Extremely Low Birthweight (ELBW) Neonates Despite the Routine Use of Topical Miconazole Prophylaxis: Trends, Risk Factors and Outcomes over an 11-Year Period

This study aims to determine the incidence, trends of systemic candidiasis and meningitis in extremely low birthweight (ELBW) neonates (<1000 gms) despite the routine use of topical miconazole prophylaxis and to compare the risk factors, adverse outcomes and comorbidities with controls. Retrospective cohort study of ELBW neonates with systemic candidiasis and meningitis over an 11-year period (1997 to 2007). Matched case control analyses were performed to determine the risk factors and comorbidities which were severe intraventricular haemorrhage (IVH), severe retinopathy of prematurity (ROP), patent ductus arteriosus (PDA) requiring treatment, necrotising enterocolitis (NEC), chronic lung disease (CLD) and cholestatic jaundice. Mortality and end organ involvement secondary to systemic candidiasis were identified as adverse outcomes. Of the 757 ELBW neonates, 51 (6.7%) had evidence of systemic candidiasis with a significant 3-fold increase in trend noted in 2007 as compared against 1997 (12.1% vs 3.8%) (RR 1.2, 95% CI, 1.06 to 1.36, P <0.001). This corresponds to a significant increasing trend of preceding or co-existent bacterial blood stream infections (BSI) in neonates with systemic candidiasis (0% in 1997 vs 7.1% in 2007, RR 1.40, 95% CI, 1.04 to 1.25, P = 0.005). On logistic regression analysis, decreasing gestational age was an independent risk factor for systemic candidiasis (OR 2.0, 95% CI, 1.52 to 2.63, P <0.001). Candida meningitis was detected in 4/38 (10.5%) and end organ involvement in 17 (33%). The organisms isolated were Candida parapsilosis 31 (61%), Candida albicans 17 (33%) and Candida glabrata 3 (5.8%). Significantly higher mortality was seen in cases when compared to controls 10/51 (19.6%) vs 76/706 (10.7%) (OR 2.02, 95% CI, 1.02 to 4.40, P <0.001). Increasing trend in the incidence of systemic candidiasis despite routine use of topical miconazole prophylaxis is of concern and future studies comparing the use of systemic fl uconazole versus oral nystatin may need to be considered.

Multistate outbreak of Escherichia coli O157:H7 associated with bagged salad.

Abstract Shiga toxin-producing Escherichia coli O157:H7 (STEC O157) is the most commonly identified serotype of STEC in the United States. An estimated 63,000 STEC O157 infections occur annually. Infection typically results in diarrhea, bloody stool, abdominal cramps, and, in some cases, hemolytic uremic syndrome. Recent outbreaks of STEC O157 have increasingly been associated with consumption of leafy greens such as lettuce and spinach. We investigated an outbreak of STEC O157 associated with the consumption of bagged salad with cases clustered in various institutional settings. A case-control study was conducted among cases from selected schools with controls matched by school and grade. Seventeen cases from three U.S. states were identified. The median age of cases was 23 years (range: 3-88) and 13 (76%) were female. Six cases were hospitalized and two died. Onset dates ranged from April 29 to May 12, 2012. The matched case-control analysis identified a single significant food service exposure: consumption of lettuce provided by a school cafeteria (median odds ratio=9.4, 95% confidence interval: 1.4-∞, p=0.0469). The implicated bagged salad product was traced back to a single production facility. Implicated growing areas were scheduled for heightened inspection for the upcoming growing season. A combination of analytical epidemiologic studies among subclusters of cases, surveillance, and traceback implicated bagged salad in this outbreak investigation.

Acute myeloid leukemia risk by industry and occupation

Acute myeloid leukemia (AML) is the most common type of leukemia found in adults. Identifying jobs that pose a risk for AML may be useful for identifying new risk factors. A matched case–control analysis was conducted using California Cancer Registry data from 1988 to 2007. This study included 8999 cases of AML and 24 822 controls. Industries with a statistically significant increased AML risk were construction (matched odds ratio [mOR] = 1.13); crop production (mOR = 1.41); support activities for agriculture and forestry (mOR = 2.05); and animal slaughtering and processing (mOR = 2.09). Among occupations with a statistically significant increased AML risk were miscellaneous agricultural workers (mOR = 1.76); fishers and related fishing workers (mOR = 2.02); nursing, psychiatric and home health aides (mOR = 1.65); and janitors and building cleaners (mOR = 1.54). Further investigation is needed to confirm study findings and to identify specific exposures responsible for the increased risks.

Transanal pullthrough for Hirschsprung disease: Matched case–control comparison of Soave and Swenson techniques

BackgroundBoth the Swenson and the Soave procedures have been adapted to a transanal approach. The purpose of this study was to compare outcomes following the transanal Swenson and Soave procedures using a matched case control analysis. MethodsA retrospective chart review was performed to identify all transanal Soave and Swenson pullthroughs done at 2 tertiary care children’s hospitals between 2000 and 2010. Patients were matched for gestational age, mean weight at time of the operation, level of aganglionosis, and presence of co-morbidities. Student’s t-test and chi-squared analysis were performed. ResultsFifty-four patients (Soave 27, Swenson 27) had adequate data for matching and analysis. Mean follow-up was 4±1.6years and 3.2 ±2.7years for the Soave and Swenson groups, respectively. No significant differences in mean operating time (Soave:191±55, Swenson:167±61min, p=0.6), overall hospital stay (6±4vs7.8±5days, p=0.7), and number with intra-operative complications (3 vs 4, p=1.0), post-operative obstructive symptoms (6 vs 9, p=0.5), enterocolitis episodes (4 vs 4, p=1.0), or fecal incontinence (0 vs 2, p=0.4) were noted. ConclusionAfter controlling for potential confounders, there were no significant differences in the short and intermediate term outcome between transanal Soave and transanal Swenson pullthrough procedures.

The relationship between vehicle roof crush and head, neck and spine injury in rollover crashes

BackgroundIt is well established that rollover crashes are associated with a higher risk of serious injury and death than other types of crashes. Some of the most serious injuries that can result from a rollover crash are those to the head, neck and spine. The mechanism of injury to these body parts in a rollover is a matter of dispute in the literature. Some authors have concluded that the magnitude of vehicle roof deformation or vertical roof crush resulting from a rollover crash is not causally associated with head and neck injury severity, while others offer support for a causal association between roof crush and the degree of injury. A better understanding of the cause of serious injuries resulting from rollover crashes is important for improving injury prevention. MethodsThis study utilized data from the National Automotive Sampling System – Crashworthiness Data System (NASS-CDS) for the years 1997 through 2007. Both cross-sectional and matched case–control designs along with a new composite injury metric termed the Head, Neck and Spine New Injury Severity Score (HNS-NISS) were used to analyze these data. ResultsThe cross-sectional analysis demonstrated a 64% (95% CI: 26–114%) increase in the odds of a life-threatening injury as estimated by the HNS-NISS with every 10cm of increased roof crush. The results of the matched case–control analysis demonstrated a 44% (95% CI: 8–91%) increase in the odds of sustaining any injury to the head, neck or spine with every 10cm increase in roof crush. ConclusionThese results lend statistical support to a causal association between roof crush and head, neck and spine injury severity. Though they do not constitute definitive proof, they do contradict previously published theories suggesting that roof deformation is unrelated to such injuries.

Risk of Guillain-Barré syndrome after 2010–2011 influenza vaccination

Influenza vaccination has been implicated in Guillain Barré Syndrome (GBS) although the evidence for this link is controversial. A case–control study was conducted between October 2010 and May 2011 in seven Italian Regions to explore the relation between influenza vaccination and GBS. The study included 176 GBS incident cases aged ≥18 years from 86 neurological centers. Controls were selected among patients admitted for acute conditions to the Emergency Department of the same hospital as cases. Each control was matched to a case by sex, age, Region and admission date. Two different analyses were conducted: a matched case–control analysis and a self-controlled case series analysis (SCCS). Case–control analysis included 140 cases matched to 308 controls. The adjusted matched odds ratio (OR) for GBS occurrence within 6 weeks after influenza vaccination was 3.8 (95 % CI: 1.3, 10.5). A much stronger association with gastrointestinal infections (OR = 23.8; 95 % CI 7.3, 77.6) and influenza-like illness or upper respiratory tract infections (OR = 11.5; 95 % CI 5.6, 23.5) was highlighted. The SCCS analysis included all 176 GBS cases. Influenza vaccination was associated with GBS, with a relative risk of 2.1 (95 % CI 1.1, 3.9). According to these results the attributable risk in adults ranges from two to five GBS cases per 1,000,000 vaccinations.

The RML of lymph node metastasis was superior to the LODDS for evaluating the prognosis of gastric cancer

ObjectiveThe aim of the study was to investigate the most appropriate system for categorization of metastatic lymph nodes among N staging (according to the 7th edition UICC/AJCC TNM Classification for Gastric Cancer), ratio between metastatic and examined lymph nodes (RML) staging, negative lymph nodes (NLN) staging and log odds of positive lymph nodes (LODDS) staging for evaluation the overall survival (OS) of gastric cancer. MethodsWe reviewed clinicopathological data of 372 gastric cancer patients who underwent radical gastrectomy plus extended lymphadenectomy with the purpose of evaluating the differences in the OS according to different categories of metastatic lymph nodes. ResultsUnivariate and multivariate analysis of data significantly identified the degree of differentiation (HR = 1.404, p = 0.015), T staging (according to the 7th edition UICC/AJCC TNM Classification for Gastric Cancer) (HR = 1.568, p = 0.024) and the RML staging (HR = 1.479, p = 0.030) as independent predictors of the OS. However, RML staging was identified as the most appropriate for evaluating the OS of gastric cancer patients following radical gastrectomy plus extended lymphadenectomy rather than N staging, NLN staging and LODDS staging by using the case–control matched analysis. With the further stratified analysis, we demonstrated that RML staging had the best prognostic homogeneity than LODDS staging, NLN staging or N staging. ConclusionsRML staging was the best system for prediction the OS of the gastric cancer patients following radical gastrectomy plus extended lymphadenectomy, rather than LODDS staging, NLN staging or N staging.

Spotlight on the February 19 Issue

Patients were randomized to receive transcutaneous stimulation or sham stimulation daily for 20 minutes over 90 days. At the end of the treatment period, 38% of patients who used the effective stimulator had a decrease in monthly migraine days by 50%, compared to 12% for the sham stimulator. See p. 697; Editorial, p. 694 In a 1:5 case-control matched analysis, cases were matched to controls according to their estimated propensity scores, based on demographics and existing vascular risk factors. Clinical diagnosis of Alzheimer disease was associated with a considerably increased risk of stroke. See p. 705 …

Alzheimer disease and risk of stroke

To investigate the risk of stroke in patients clinically diagnosed with Alzheimer disease (AD) compared with non-AD patients with similar vascular risk factors. Using data obtained from Taiwan's National Health Insurance Research Database, we evaluated the risk of ischemic stroke (IS) and intracerebral hemorrhage (ICH) in patients with AD (n = 980) who had no history of stroke, vascular dementia, or other cerebral degenerative diseases. Our evaluation period spanned from 2000 to 2010. We performed a 1:5 case-control matched analysis, in which cases were matched to controls according to their estimated propensity scores, which were based on demographics and existing vascular risk factors. This approach reduced selection bias. Cox proportional hazards regression analysis was then used to estimate the risk of IS and ICH in AD, conditional for matched pairs. Overall, patients with AD had a higher risk of IS and ICH than those without AD. The incidence of IS in AD cases and non-AD controls was 37.8 and 23.2 per 1,000 person-years, with an adjusted hazard ratio of 1.66 (95% confidence interval, 1.37-2.01, p < 0.001). The incidence of ICH in AD cases and non-AD controls was 5.2 and 3.0 per 1,000 person-years, with an adjusted hazard ratio of 1.70 (95% confidence interval, 1.03-2.79, p = 0.037). Clinical diagnosis of AD is associated with considerably increased risk of stroke development.

Patients with Persistent New-Onset Diabetes after Transplantation Have Greater Weight Gain after Kidney Transplantation

The purpose of the present study was to evaluate the difference in BMI pattern between patients with persistent new-onset diabetes after transplantation (P-NODAT) and without new-onset diabetes after transplantation (N-NODAT) in a retrospective matched case-control (1:3) analysis. Thirty-six patients who developed P-NODAT were identified among 186 adult renal transplant recipients with no evidence of pretransplant diabetes mellitus who underwent kidney transplantation from September 1997 to March 2008 and were treated with a triple regimen including tacrolimus. The controls were selected to match the patients for pretransplant BMI, age at transplantation (± 5 yr), and date of transplantation (± 12 months). Finally, 20 P-NODAT patients and 60 N-NODAT patients were selected. The pre- and posttransplant BMI data were collected every 16 weeks for up to 80 weeks. The clinical characteristics did not differ between the P-NODAT group and N-NODAT group. BMI increased faster in the P-NODAT group than in the N-NODAT group. The mixed-model analysis showed that patients with P-NODAT exhibited a faster increase in BMI. P-NODAT is associated with posttransplant weight gain. The risk of P-NODAT should be considered in patients with rapid weight gain after transplantation.

Necrotising enterocolitis in infants with congenital heart disease: the role of enteral feeds

Necrotising enterocolitis is a rare, though catastrophic complication that may occur in term newborns with congenital heart disease. There is considerable controversy regarding the factors that lead to necrotising enterocolitis in this population. We sought to determine the incidence of necrotising enterocolitis among term and near-term newborns with congenital heart disease, focusing on the relationship of enteral feeding to this complication. In this retrospective study, we identified the incidence of necrotising enterocolitis among 1551 newborns admitted to our cardiac intensive care unit between July 1, 2002 and July 1, 2010. In order to understand the impact of enteral feeding upon the development of necrotising enterocolitis, we undertook a nested 2:1 matched case-control analysis to compare feeding patterns in an age- and lesion-matched control population. Necrotising enterocolitis developed in 45 term or near-term infants (3%). The majority of these cases, 27 (60%), occurred in the post-operative period after the introduction of enteral feeds. This subgroup was used for matched analysis. There were no differences in enteral feeding patterns among the patients who developed necrotising enterocolitis and their matched controls. The overall mortality rate for patients who developed necrotising enterocolitis was 24.4% (11 out of 45). Despite numerous advances in the care of infants with congenital heart disease, necrotising enterocolitis remains a significant source of morbidity and mortality. In these infants, there is no clear relationship between enteral feeding patterns and the development of necrotising enterocolitis in the post-operative period. The benefits of graduated feeding advancements to avoid the development of necrotising enterocolitis remain unproven.

Morbidity of Staged Proctectomy After Hepatectomy for Colorectal Cancer: A Matched Case–Control Analysis

Proctectomy after hepatectomy, or the reverse approach, is an alternative to traditional sequencing for advanced liver metastases with asymptomatic colorectal primary tumors. We sought to evaluate the surgical morbidity of proctectomy for colorectal cancer after previous liver surgery. A single-institution colorectal database was queried for patients treated with proctectomy after previous hepatectomy from 2003 to 2011. Reverse-approach patients (n = 31) were matched 1:2 with a cohort of standard proctectomy patients (n = 62) using operation, age, gender, and surgeon. Perioperative factors were analyzed by univariate/multivariate models for associations with complications graded by Dindo-Clavien criteria. Thirty-one patients with adenocarcinoma ≤ 20 cm from the anal verge underwent proctectomy after hepatectomy. Median time from hepatectomy to proctectomy was 5.1 months. Median tumor distance was 8.5 cm. Before proctectomy, patients underwent 28 (90 %) major hepatectomies and 7 (22 %) portal vein embolizations. There were no perioperative deaths. Reverse-approach patients did not differ from control patients in operation, demographics, body mass index (BMI), comorbidities, tumor distance, operative time, estimated blood loss, length of stay, or complication rates (p > 0.05). Grade 2 or higher complications developed in 42 % of reverse-approach and 27 % of standard proctectomies (p = 0.17). Grade 3 or higher complications developed in 10 % and 8 %, respectively (p = 1.00). Independent predictors of complications of grade 2 or higher were BMI ≥30 kg/m(2) (p = 0.007), operative time ≥300 min (p = 0.012), intraoperative transfusion (p = 0.044), concurrent procedures (p = 0.024), and age ≥50 years (p = 0.030). Risk factors for morbidity of staged proctectomy are similar to those for standard proctectomy. In selected patients, the reverse-approach proctectomy is safe with acceptable morbidity.

Disturbed microstructural integrity of the frontostriatal fiber pathways and executive dysfunction in children with attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is recognized as an early-onset neuropsychiatric disorder with executive dysfunctions and neurobiological deficits. The authors compared executive functions and microstructural integrity of the frontostriatal circuit in children with ADHD and typically developing children. Method We assessed 25 children with ADHD and 25 age-, sex-, handedness- and intelligence-matched typically developing children by using psychiatric interviews, the Wechsler Intelligence Scale for Children - third edition, and the tasks involving executive functions in the Cambridge Neuropsychological Test Automated Battery. The frontostriatal tracts were reconstructed by diffusion spectrum imaging tractography and were subdivided into four functionally distinct segments, including dorsolateral, medial prefrontal, orbitofrontal and ventrolateral tracts. Tract-specific and matched case-control analyses were used and generalized fractional anisotropy values were computed. Children with ADHD had lower generalized fractional anisotropy of all the bilateral frontostriatal fiber tracts and poorer performance in verbal and spatial working memory, set-shifting, sustained attention, cognitive inhibition and visuospatial planning. The symptom severity of ADHD and the executive functioning performance significantly correlated with integrity of the frontostriatal tracts, particularly the left orbitofrontal and ventrolateral tracts. Children with ADHD also demonstrated loss of the leftward asymmetry in the dorsolateral and medial prefrontal tracts that was present in typically developing children. Our findings demonstrate disturbed structural connectivity of the frontostriatal circuitry in children with ADHD and add new evidence of associations between integrity of the frontostriatal tracts and measures of core symptoms of ADHD and a wide range of executive dysfunctions in both groups.

Case-matched analysis comparing outcomes of revisional versus primary laparoscopic Roux-en-Y gastric bypass

Laparoscopic Roux-en-Y gastric bypass (LRYGB) is one of the most common approaches used to revise post-bariatric patients with inadequate weight loss or significant weight regain. Previous studies have analyzed the outcomes of open revisional RYGB versus primary RYGB, but no case-control matched analysis comparing revisional LRYGB versus primary LRYGB has been performed. Our cohort includes 37 consecutive patients who underwent revisional LRYGB because of unsatisfactory weight loss or weight regain matched in a 1:2 ratio with 74 control patients who underwent primary LRYGB. Matching included the following parameters: age, gender, preoperative body mass index and comorbidities (diabetes, obstructive sleep apnea, and hypertension). The revisional group had longer length of stay compared with the primary group (3.8 vs. 2.4 days, P = 0.02) and a higher conversion to laparotomy rate (10.8 vs. 0 %, P = 0.01). The revisional group had a higher 30-day morbidity compared with the primary group (27 vs. 8.1 %, P = 0.02). There were no deaths in both groups. The two groups had similar 30-day readmission and 30 day reoperation rates. At 3, 6, and 12 months of follow-up, the revisional LRYGB group had significantly lower percent of excess weight loss (EWL) than the primary LRYGB group (3 months, 30 vs. 38.4, P = 0.001; 6 months, 36.3 vs. 52.9, P = 0.001; 12 months, 46.5 vs. 68.2, P = 0.001). Revisional LRYGB is characterized by lower EWL and higher morbidity than primary LRYGB. However, our data suggest that revisional LRYGB is still capable of providing significant weight loss in these high-risk patients.

P-0119 Beneficial Trends of Second Line Chemotherapy in Advanced Pancreatic Cancer

IntroductionDespite the lack of high-quality clinical trial data suggesting that second-line chemotherapy (SLC) may affect survival on metastatic pancreatic cancer (mPC), most of centers utilizes them after the failure of initial treatment in patients who maintain a good performance status. The aim of the present study was to review our institutional experience with SLC and estimate its role in overall survival (OS). MethodsWe performed a retrospective matched case-control analysis based on search of medical records in 106 consecutive patients with mPC at our institution. Patients received first line chemotherapy (FLC) and SLC (n=49) or FLC only (n =57) from September 2005 to December 2010. Case matching was performed with respect to age (< 60y versus≥60y), topography (head of the pancreas versus body or tail), sites of metastasis. Overall survival was analyzed by Kaplan-Meier method ResultsMedian age was 63 (32-86) and 60 (38-85) for SLC group and FLC group respectively. There was no significant difference between the two groups regarding topography, TNM stage at diagnosis, and sites of metastasis. The main site of metastasis was the liver (24.4%), followed by peritoneum (2.8%). Median follow-up of both groups was 8.4 months (0.23-54.93 months). First line treatment consisted of Gemcitabine (55.1% x 49.1%) and Gemcitabine+Cisplatin (18.4%x14%) in SLC and FLC group respectively. The most used second line treatment was Capecitabine (32.7%), followed by FOLFOX (16.3%), and Fluorouracil (10.2%). The Kaplan-Meier estimate of the overall median survival, 1-year and 2-years survival rate was 15.72 months versus 7.2 months (P=0,021), and 60% vs 32%, and 30% vs 19% in SLC and FLC group, respectively. ConclusionOur result suggests that second-line chemotherapy may be beneficial to improve overall survival in patients with advanced pancreatic cancer. It's important that new and ongoing clinical trials clarify which is the best chemotherapy scheme in this setting.

Beneficial trends of second-line chemotherapy in advanced pancreatic cancer.

e14680 Background: Despite the lack of high-quality clinical trial data suggesting that second-line chemotherapy (SLC) may affect survival on metastatic pancreatic cancer (mPC), most of centers utilizes them after the failure of initial treatment in patients who maintain a good performance status. The aim of the present study was to review our institutional experience with SLC and estimate its role in overall survival (OS). Methods: We performed a retrospective matched case-control analysis based on search of medical records in 106 consecutive patients with mPC at our institution. Patients received first line chemotherapy (FLC) and SLC (n = 49) or FLC only (n =57) from September 2005 to December 2010. Case matching was performed with respect to age (&lt; 60y versus ≥ 60y), topography (head of the pancreas versus body or tail), sites of metastasis. Overall survival was analyzed by Kaplan-Meier method. Results: Median age was 63 (32-86) and 60 (38-85) for SLC group and FLC group respectively. There was no significant difference between the two groups regarding topography, TNM stage at diagnosis, and sites of metastasis. The main site of metastasis was the liver (24,4%), followed by peritoneum (2,8%).Median follow-up of both groups was 8.4 months (0.23m-54.93m). First line treatment consisted of Gemcitabine (55.1% x 49.1%) and gemcitabine + cisplatin (18.4%x14%) in SLC and FLC group respectively. The most used second line treatment was Capecitabine (32.7%), followed by Folfox (16.3%), and Fluoracil (10.2%). The Kaplan-Meier estimate of the overall median survival, 1-year and 2-years survival rate was 15.72 months versus 7.2 months (p:0.021), and 60% vs. 32%, and 30% vs. 19% in SLC and FLC group, respectively. Conclusions: Our result suggests that second-line chemotherapy may be beneficial to improve overall survival in patients with advanced pancreatic cancer. It’s important that new and ongoing clinical trials clarify which is the best chemotherapy scheme in this setting.

Prolonged persistent patent ductus arteriosus: potential perdurable anomalies in premature infants

Patent ductus arteriosus (PDA) is a common condition among preterm infants. Controversy exists regarding the risk-benefit ratio of early closure of PDAs by either medical or surgical treatments. On the other hand, potential morbidities associated with no or delayed closure has not been well studied. The objective of the study was to determine if there is an association of prolonged persistent PDA (PP-PDA) with various morbidities in infants ≤28 weeks or 1250 g. This matched case-control analysis includes preterm infants with a diagnosis of PDA over a period of 28 months in a single level III center in the USA. The predictive variable was the presence of a PP-PDA (PDA>3 weeks). Cases were infants with PP-PDA and controls were those with PDA but not PP-PDA (two controls for each case). Outcome variables included days on mechanical ventilation and with oxygen treatment, length of hospital stay, bronchopulmonary dysplasia (BPD), retinopathy of prematurity stage III-V (ROP) necrotizing enterocolitis grade II or more (NEC), delayed growth, direct hyperbilirubinemia >4 mg dl(-1) and osteopenia of prematurity. Data was obtained from database collected prospectively and from the review of clinical records when necessary. Statistics included ANOVA, Kaplan-Meier curves and χ (2). Significance was set at P<0.05. PP-PDA was associated with a significant increase in the number of days of mechanical ventilation, oxygen treatment and length of hospital stay, and in the rates of BPD (60% vs 4.5%), NEC (29% vs 5%), ROP (43% vs 5%), direct hyperbilirubinemia (41% vs 3%), osteopenia (44% vs 6%), parenteral nutrition for >40 days (70% vs 21%), tracheostomy during the hospitalization (15% vs 0%) and delayed growth (70% vs 21%), were also significantly higher in babies with PP-PDA. A prolonged exposure to PDA does not seem to be inconsequential for some infants and is associated with an increase prevalence of severe morbidities with potential long lasting effects.

Matched Case Control Analysis Comparing Long Term Survival of Multiple Myeloma Patients Who Received Stem Cell Transplant with and without Idiotype-Pulsed Dendritic Cell Vaccine

Abstract 636Cellular vaccine may offer additional benefit as consolidative therapy after autologous stem cell transplant (ASCT) for multiple myeloma (MM). We have reported previously from two phase II studies the survival of MM patients who received APC8020 (autologous antigen presenting cell vaccine) after ASCT (Lacy, AJH ’09, (84): 799; Lin, ASH annual meeting 2010, abstract 1958). To determine if there was an outcome advantage for additional consolidative vaccine therapy after ASCT, we performed this matched case control analysis comparing the survival of patients who received ASCT only (control) at Mayo Clinic to those who received APC8020 after ASCT in the same time period. Forty-three study patients accrued between July 1998 and March 2002 were eligible for matching. To reduce bias from disease risks and transplant-related mortality, control patients were required to be alive and progression free six months after transplant and have a M-spike value of < 2g/dL at 4 mos (1st study) or 9 mos (2nd study) after transplant, similar to post-ASCT patients who were enrolled in the two APC8020 studies. A total of 111 control patients were eligible for matching. Control patients were matched to study patients by age (+/− 5 yrs), ISS (International Staging System) stage, and plasma cell labeling index (PLCI, either >= 3 or < 3). A matched control was not identified for one study patient. Of the remaining 42 study patients, all had at least one matched control patient. Thirty-two patients had 2 matched controls. Cox proportional hazards analysis showed that there was no statistically significant difference in time to progression between the study and control patients (HR 1.54, 95% CI 0.92 – 2.58, p = 0.1). However the overall survival is significantly improved among the study patients (HR 0.54, 95% CI 0.30 – 0.99, p = 0.05). This analysis is the only known report of long-term follow-up of the largest group of MM patients treated with APC8020 vaccine. While many current prognostic tests were not available at the time of the initial vaccine studies, the control patients in this analysis were matched by known disease risks that are still in use today. The survival advantage in study patients remained statistically significant compared to matched controls. Interestingly, the time to progression is unchanged between study and control patients. This is similar to other reports of vaccine therapy such as in sipuleucel-T (Provenge™) in prostate cancer where an overall survival benefit is seen without change in progression-free survival. A larger, randomized phase III study is needed to confirm the encouraging survival benefit of this treatment modality in MM. Further insight into the mechanisms of action of APC8020 is needed to improve our understanding of the role of this therapy in the context of current practice of MM maintenance therapies. Disclosures:Sims:Dendreon Corporation: Employment.

Signs and symptoms predicting influenza in children: a matched case–control analysis of prospectively collected clinical data

We aimed to determine whether there are signs or symptoms that could help clinicians to distinguish between influenza and other respiratory infections. The clinical data for this matched case-control analysis were derived from a 2-year prospective cohort study of respiratory infections among children aged≤13 years. At any signs of respiratory infection, the children were examined and nasal swabs were obtained for virologic analyses. Cases were 353 children with laboratory-confirmed influenza and controls were 353 children with respiratory symptoms who tested negative for influenza. Cases and controls were matched for gender, age, and timing of the visit. In the multivariate conditional logistic regression analyses, fever was the only sign that independently predicted influenza virus infection, with odds ratios ranging from 13.55 (95% confidence interval [CI], 6.90-26.63) to 50.10 (95% CI, 16.25-154.45), depending on the degree of fever. In all analyses, the predictive capability of fever increased with incremental elevations in the child's temperature. The likelihood ratio of fever≥40.0°C in predicting influenza was 6.00 (95% CI, 2.80-12.96). Among unselected children seen as outpatients during influenza outbreaks, fever is the only reliable predictor of influenza virus infection. The optimal use of influenza-specific antiviral drugs in children may require virologic confirmation.

Heparin-induced thrombocytopenia type II in a surgical intensive care unit

PurposeThe aim of this study was to investigate the epidemiology of and outcome from heparin-induced thrombocytopenia type II (HIT) in surgical intensive care unit (ICU) patients. Patients and MethodsAll 13 948 patients admitted to a university hospital surgical ICU between January 2004 and March 2008 were included in this retrospective cohort study. ResultsOf 349 patients with a clinical suspicion of HIT, 88 patients had platelet factor 4/heparin antibodies using enzyme-linked immunosorbent assay. The prevalence and incidence of HIT were 0.82% and 0.63%, respectively. The complication rate was 43.5%, and the ICU and hospital mortality rates were 23.9% and 33%, respectively. In a multivariable analysis, the nadir platelet count (odds ratio, 1.03; 95% confidence interval, 1.01-1.05; P = .048) was the only factor independently associated with risk of death in these patients. In a nested matched case-control analysis, mortality rates were similar in patients with HIT and in the matched controls. However, complication rates were higher, and ICU and hospital lengths of stay were longer in patients with HIT compared with those of the control group. ConclusionsIn this cohort of surgical ICU patients, HIT was associated with increased morbidity but not mortality rates compared with a nested matched control group. The nadir platelet count was independently associated with a higher risk of inhospital death in these patients.