Photothermal release and recovery of mesenchymal stem cells from substrates functionalized with gold nanorods.

Mesenchymal stem cell therapies show great promise in regenerative medicine. However, to generate clinically relevant numbers of these stem cells, significant in vitro expansion of the cells is required before transplantation into the affected wound or defect. The current gold standard protocol for recovering in vitro cultured cells involves treatment with enzymes such as trypsin which can affect the cell phenotype and ability to interact with the environment. Alternative enzyme free methods of adherent cell recovery have been investigated, but none match the convenience and performance of enzymatic detachment. In this work we have developed a synthetically simple, low cost cell culture substrate functionalized with gold nanorods that can support cell proliferation and detachment. When these nanorods are irradiated with biocompatible low intensity near infrared radiation (785 nm, 560 mWcm-2) they generate localized surface plasmon resonance induced nanoscale heating effects which trigger detachment of adherent mesenchymal stem cells. Through simulations and thermometry experiments we show that this localized heating is concentrated at the cell-nanorod interface, and that the stem cells detached using this technique show either similar or improved multipotency, viability and ability to differentiate into clinically desirable osteo and adipocytes, compared to enzymatically harvested cells. This proof-of-principle work shows that photothermally mediated cell detachment is a promising method for recovering mesenchymal stem cells from in vitro culture substrates, and paves the way for further studies to scale up this process and facilitate its clinical translation. STATEMENT OF SIGNIFICANCE: New non-enzymatic methods of harvesting adherent cells without damaging or killing them are highly desirable in fields such as regenerative medicine. Here, we present a synthetically simple, non-toxic, infra-red induced method of harvesting mesenchymal stem cells from gold nanorod functionalized substrates. The detached cells retain their ability to differentiate into therapeutically valuable osteo and adipocytes. This work represents a significant improvement on similar cell harvesting studies due to: its simplicity; the use of clinically valuable stem cells as oppose to immortalized cell lines; and the extensive cellular characterization performed. Understanding, not just if cells live or die but how they proliferate and differentiate after photothermal detachment will be essential for the translation of this and similar techniques into commercial devices.

Female pelvic medicine and reconstructive surgery challenges on behalf of the Collaborative Research in Pelvic Surgery Consortium: managing complicated cases.

This case presents the work-up and management of a patient experiencing acute kidney injury, urinary retention, and neuropathy following surgery for pelvic organ prolapse and stress urinary incontinence. Four international experts provide their evaluation of and approach to this complex case.

Functional Index-3: A Valid and Reliable Functional Outcome Assessment Measure in Patients With Dermatomyositis and Polymyositis.

OBJECTIVE: Patients with dermatomyositis (DM) and polymyositis (PM) have reduced muscle endurance.The aim of this study was to streamline the Functional Index-2 (FI-2) by developing the Functional Index-3 (FI-3) and to evaluate its measurement properties, content and construct validity, and intra- and interrater reliability. METHODS: A dataset of the previously performed and validated FI-2 (n = 63) was analyzed for internal redundancy, floor, and ceiling effects. The content of the FI-2 was revised into the FI-3. Construct validity and intrarater reliability of FI-3 were tested on 43 DM and PM patients at 2 rheumatology centers. Interrater reliability was tested in 25 patients. The construct validity was compared with the Myositis Activities Profile (MAP), Health Assessment Questionnaire (HAQ), and Borg CR-10 using Spearman correlation coefficient. RESULTS: Spearman correlation coefficients of 63 patients performing FI-3 revealed moderate to high correlations between shoulder flexion and hip flexion tasks and similar correlations with MAP and HAQ scores; there were lower correlations for neck flexion task. All FI-3 tasks had very low to moderate correlations with the Borg scale. Intraclass correlation coefficients (ICC) of FI-3 tasks for intrarater reliability (n = 25) were moderate to good (0.88-0.98). ICC of FI-3 tasks for interrater reliability (n = 17) were fair to good (range 0.83-0.96). CONCLUSION: The FI-3 is an efficient and valid method for clinically assessing muscle endurance in DM and PM patients. FI-3 construct validity is supported by the significant correlations between functional tasks and the MAP, HAQ, and Borg CR-10 scores.

Human neuropeptide substance P self-assembles into semi-flexible nanotubes that can be manipulated for nanotechnology.

Substance P neuropeptide is here reported to self-assemble into well-defined semi-flexible nanotubes. Using a blend of synchrotron small angle X-ray scattering, atomic force microscopy and other biophysical techniques, the natural peptide is shown to self-assemble into monodisperse 6 nm wide nanotubes, which can closely associate into nano-arrays with nematic properties. Using simple protocols, the nanotubes could be precipitated or mineralised while conserving their dimensions and core-shell morphology. Our discovery expands the small number of available monodisperse peptide nanotube systems for nanotechnology, beyond direct relevance to biologically functional peptide nanostructures since the substance P nanotubes are fundamentally different from typical amyloid fibrils.

Underarm bracing for adolescent idiopathic scoliosis leads to flatback deformity: the role of sagittal spinopelvic parameters.

AIMS: The aim of this study was to determine the influence of pelvic parameters on the tendency of patients with adolescent idiopathic scoliosis (AIS) to develop flatback deformity (thoracic hypokyphosis and lumbar hypolordosis) and its effect on quality-of-life outcomes. PATIENTS AND METHODS: This was a radiological study of 265 patients recruited for Boston bracing between December 2008 and December 2013. Posteroanterior and lateral radiographs were obtained before, immediately after, and two-years after completion of bracing. Measurements of coronal and sagittal Cobb angles, coronal balance, sagittal vertical axis, and pelvic parameters were made. The refined 22-item Scoliosis Research Society (SRS-22r) questionnaire was recorded. Association between independent factors and outcomes of postbracing ≥ 6° kyphotic changes in the thoracic spine and ≥ 6° lordotic changes in the lumbar spine were tested using likelihood ratio chi-squared test and univariable logistic regression. Multivariable logistic regression models were then generated for both outcomes with odds ratios (ORs), and with SRS-22r scores. RESULTS: Reduced T5-12 kyphosis (mean -4.3° (sd 8.2); p < 0.001), maximum thoracic kyphosis (mean -4.3° (sd 9.3); p < 0.001), and lumbar lordosis (mean -5.6° (sd 12.0); p < 0.001) were observed after bracing treatment. Increasing prebrace maximum kyphosis (OR 1.133) and lumbar lordosis (OR 0.92) was associated with postbracing hypokyphotic change. Prebrace sagittal vertical axis (OR 0.975), prebrace sacral slope (OR 1.127), prebrace pelvic tilt (OR 0.940), and change in maximum thoracic kyphosis (OR 0.878) were predictors for lumbar hypolordotic changes. There were no relationships between coronal deformity, thoracic kyphosis, or lumbar lordosis with SRS-22r scores. CONCLUSION: Brace treatment leads to flatback deformity with thoracic hypokyphosis and lumbar hypolordosis. Changes in the thoracic spine are associated with similar changes in the lumbar spine. Increased sacral slope, reduced pelvic tilt, and pelvic incidence are associated with reduced lordosis in the lumbar spine after bracing. Nevertheless, these sagittal parameter changes do not appear to be associated with worse quality of life. Cite this article: Bone Joint J 2019;101-B:1370-1378.

Origami-based impact mitigation via rarefaction solitary wave creation.

The principles underlying the art of origami paper folding can be applied to design sophisticated metamaterials with unique mechanical properties. By exploiting the flat crease patterns that determine the dynamic folding and unfolding motion of origami, we are able to design an origami-based metamaterial that can form rarefaction solitary waves. Our analytical, numerical, and experimental results demonstrate that this rarefaction solitary wave overtakes initial compressive strain waves, thereby causing the latter part of the origami structure to feel tension first instead of compression under impact. This counterintuitive dynamic mechanism can be used to create a highly efficient-yet reusable-impact mitigating system without relying on material damping, plasticity, or fracture.

Cost-Effectiveness Studies in the ICU: A Systematic Review.

OBJECTIVES: Cost-effectiveness analyses are increasingly used to aid decisions about resource allocation in healthcare; this practice is slow to translate into critical care. We sought to identify and summarize original cost-effectiveness studies presenting cost per quality-adjusted life year, incremental cost-effectiveness ratios, or cost per life-year ratios for treatments used in ICUs. DESIGN: We conducted a systematic search of the English-language literature for cost-effectiveness analyses published from 1993 to 2018 in critical care. Study quality was assessed using the Drummond checklist. SETTING: Critical care units. PATIENTS OR SUBJECTS: Critical care patients. INTERVENTIONS: Identified studies with cost-effectiveness analyses. MEASUREMENTS AND MAIN RESULTS: We identified 97 studies published through 2018 with 156 cost-effectiveness ratios. Reported incremental cost-effectiveness ratios ranged from -$119,635 (hypothetical cohort of patients requiring either intermittent or continuous renal replacement therapy) to $876,539 (data from an acute renal failure study in which continuous renal replacement therapy was the most expensive therapy). Many studies reported favorable cost-effectiveness profiles (i.e., below $50,000 per life year or quality-adjusted life year). However, several therapies have since been proven harmful. Over 2 decades, relatively few cost-effectiveness studies in critical care have been published (average 4.6 studies per year). There has been a more recent trend toward using hypothetical cohorts and modeling scenarios without proven clinical data (2014-2018: 19/33 [58%]). CONCLUSIONS: Despite critical care being a significant healthcare cost burden there remains a paucity of studies in the literature evaluating its cost effectiveness.

Mechanical Autonomous Stochastic Heat Engine.

Stochastic heat engines are devices that generate work from random thermal motion using a small number of highly fluctuating degrees of freedom. Proposals for such devices have existed for more than a century and include the Maxwell demon and the Feynman ratchet. Only recently have they been demonstrated experimentally, using, e.g., thermal cycles implemented in optical traps. However, recent experimental demonstrations of classical stochastic heat engines are nonautonomous, since they require an external control system that prescribes a heating and cooling cycle and consume more energy than they produce. We present a heat engine consisting of three coupled mechanical resonators (two ribbons and a cantilever) subject to a stochastic drive. The engine uses geometric nonlinearities in the resonating ribbons to autonomously convert a random excitation into a low-entropy, nonpassive oscillation of the cantilever. The engine presents the anomalous heat transport property of negative thermal conductivity, consisting in the ability to passively transfer energy from a cold reservoir to a hot reservoir.

Unidirectional Transition Waves in Bistable Lattices.

We present a model system for strongly nonlinear transition waves generated in a periodic lattice of bistable members connected by magnetic links. The asymmetry of the on-site energy wells created by the bistable members produces a mechanical diode that supports only unidirectional transition wave propagation with constant wave velocity. We theoretically justify the cause of the unidirectionality of the transition wave and confirm these predictions by experiments and simulations. We further identify how the wave velocity and profile are uniquely linked to the double-well energy landscape, which serves as a blueprint for transition wave control.

Using stroke thrombolysis to describe the role of repetition in learning a cognitive skill.

OBJECTIVE: To empirically describe how independent physicians develop a new cognitive clinical skill through repetition using the initiation of a stroke thrombolysis programme as a model. METHODS: This was a retrospective cohort study from April 2009 to March 2013. The setting was a single-centre, Canadian tertiary-care community hospital. The participants were 52 physicians with no prior formal training in stroke thrombolysis assuming a new role of being front-line hyperacute stroke physicians. The main outcome measures were: time needed to accrue experience, door-to-needle time (DTN), with achievement of expertise defined as an average of ≤ 60 minutes, computed tomography (CT)-to-needle time (CTN), with achievement of expertise defined as an average of ≤ 35 minutes, usage of an outside expert stroke telemedicine service, and complication rates with intracranial haemorrhage (ICH). RESULTS: Seven hundred and fifteen cases of hyperacute stroke were seen over the 4-year study period. On average, a physician saw 0.025 cases per hour of code stroke coverage provided; only seven (13.5%) accrued more than 20 code stroke cases and only six (11.6%) ordered thrombolysis more than 10 times. By regression analysis, the average first DTN was 81.0 minutes (95% confidence interval [CI], 77.1-84.9 minutes) and incrementally improved linearly by 0.259 minutes per case seen (95% CI, 0.182-0.337 minutes per case). An estimated 71 cases needed to be seen for the average physician to achieve expertise. Results using CTN were highly similar. Overall, physicians used the external stroke telemedicine providers 23.2% of the time for their first five cases, a rate that decreased to about 5% by the 45th case. Over time, ICH rates were kept at expected benchmarks. CONCLUSIONS: Accruing sufficient experience of a new cognitive clinical skill can be challenging for independent physicians, with expertise gradually emerging in a largely linear fashion only after much repetition.

The high-affinity human IgG receptor Fc gamma receptor I (FcγRI) is not associated with vascular leakage of dengue.

BACKGROUND: Dengue is a major public health problem in many tropical and sub-tropical countries. Vascular leakage and shock are identified as the major causes of deaths in patients with severe dengue. Studies have suggested the potential role of Fc gamma receptors I (FcγRI) in the pathogenesis of dengue. We hypothesized that the circulating level of Fcγ receptor I could potentially be used as an indicator in assisting early diagnosis of severe dengue. RESULTS: A selected cohort of 66 dengue patients including 42 dengue with signs of vascular leakage, and 24 dengue without signs of vascular leakage were identified and were afterwards referred to as 'cases' and 'controls' respectively. Thirty seven normal healthy controls were also recruited in this study. The circulating level of FcγRI was quantified from the serum using enzyme-link immunosorbent assay (ELISA). The levels of FcγRI in both groups of patients with and without vascular leakage were found to be significantly higher than the normal healthy controls (P < 0.001). However, there was no significant difference found between patients with vascular leakage and those without vascular leakage (p = 0.777). CONCLUSION: We suggest that FcγRI is not associated with the vascular leakage in dengue. However, further studies are necessary to delineate the role of FcγRI in antibody-dependent enhancement (ADE) mechanism.

Does this patient have an exudative pleural effusion? The Rational Clinical Examination systematic review.

IMPORTANCE: Thoracentesis is performed to identify the cause of a pleural effusion. Although generally safe, thoracentesis may be complicated by transient hypoxemia, bleeding, patient discomfort, reexpansion pulmonary edema, and pneumothorax. OBJECTIVE: To identify the best means for differentiating between transudative and exudative effusions and also to identify thoracentesis techniques for minimizing the risk of complications by performing a systematic review the evidence. DATA SOURCES: We searched The Cochrane Library, MEDLINE, and Embase from inception to February 2014 to identify relevant studies. STUDY SELECTION: We included randomized and observational studies of adult patients undergoing thoracentesis that examined diagnostic tests for differentiating exudates from transudates and evaluated thoracentesis techniques associated with a successful procedure with minimal complications. DATA EXTRACTION AND SYNTHESIS: Two investigators independently appraised study quality and extracted data from studies of laboratory diagnosis of pleural effusion for calculation of likelihood ratios (LRs; n = 48 studies) and factors affecting adverse event rates (n = 37 studies). RESULTS: The diagnosis of an exudate was most accurate if cholesterol in the pleural fluid was greater than 55 mg/dL (LR range, 7.1-250), lactate dehydrogenase (LDH) was greater than 200 U/L (LR, 18; 95% CI, 6.8-46), or the ratio of pleural fluid cholesterol to serum cholesterol was greater than 0.3 (LR, 14; 95% CI, 5.5-38). A diagnosis of exudate was less likely when all Light's criteria (a ratio of pleural fluid protein to serum protein >0.5, a ratio of pleural fluid LDH to serum LDH >0.6, or pleural fluid LDH >two-thirds the upper limit of normal for serum LDH) were absent (LR, 0.04; 95% CI, 0.02-0.11). The most common complication of thoracentesis was pneumothorax, which occurred in 6.0% of cases (95% CI, 4.0%-7.0%). Chest tube placement was required in 2.0% of procedures (95% CI, 0.99%-2.9%) in which a patient was determined to have radiographic evidence of a pneumothorax. With ultrasound, a radiologist's marking the needle insertion site was not associated with decreased pneumothorax events (skin marking vs no skin marking odds ratio [OR], 0.37; 95% CI, 0.08-1.7). Use of ultrasound by any experienced practitioner also was not associated with decreased pneumothorax events (OR, 0.55; 95% CI, 0.06-5.3). CONCLUSIONS AND RELEVANCE: Light's criteria, cholesterol and pleural fluid LDH levels, and the pleural fluid cholesterol-to-serum ratio are the most accurate diagnostic indicators for pleural exudates. Ultrasound skin marking by a radiologist or ultrasound-guided thoracentesis were not associated with a decrease in pneumothorax events.

Factors associated with readmissions and outcomes of patients hospitalized for inflammatory bowel disease.

BACKGROUND & AIMS: Patients with inflammatory bowel diseases (IBD) are hospitalized frequently. We sought to identify factors associated with risk for IBD-related readmission to the hospital. METHODS: We performed a retrospective analysis of 26,403 patients hospitalized for IBD from 2004 through 2010 using the Canadian Institute for Health Information Discharge Abstract databases. We examined whether demographic factors, comorbidity, and hospital IBD admission volume were associated with readmission rates, length of stay, bowel resection, and mortality. RESULTS: Young, middle-age, and elderly adults were more than twice as likely to undergo surgery during hospitalization than pediatric patients. Elderly patients with IBD had a nearly 40-fold greater in-hospital mortality than pediatric patients (odds ratio, 37.4; 95% confidence interval [CI], 5.17-270.0). In-hospital mortality was lower at hospitals with the highest volume of IBD patients than at those with low volume (odds ratio, 0.20; 95% CI, 0.05-0.97). Rates of readmission were lower for patients with ulcerative colitis than Crohn's disease (hazard ratio, 0.79; 95% CI, 0.72-0.86). The hazard ratios for readmission among young, middle-age, and elderly adults, compared with those of pediatric patients, were 0.79 (95% CI, 0.69-0.90), 0.57 (95% CI, 0.49-0.65), and 0.44 (95% CI, 0.37-0.53), respectively. Rates of readmission were lower at the highest-volume, compared with the lowest-volume, hospitals (hazard ratio, 0.78; 95% CI, 0.64-0.96). CONCLUSIONS: Based on a retrospective database analysis, pediatric patients with IBD are at greater risk for readmission to the hospital than older patients. Efforts should be made to determine whether factors that contribute to this risk are preventable. The lower risk of readmission at the highest-volume hospitals may reflect optimal management during hospitalization or follow-up evaluation.

National estimates of the burden of inflammatory bowel disease among racial and ethnic groups in the United States.

BACKGROUND: The epidemiology of inflammatory bowel disease (IBD) is poorly characterized in minorities in the U.S. We sought to enumerate the burden of IBD among racial and ethnic groups using national-level data. METHODS: Data from the National Health Interview Survey was used to calculate prevalence and incidence of IBD among adults (≥ 18 years) in 1999. The Nationwide Inpatient Sample was queried to ascertain rates of IBD-related hospitalizations and the Underlying Cause of Death Database was accessed to quantify IBD-related mortality. RESULTS: An estimated 1,810,773 adult Americans were affected by IBD yielding a prevalence of 908/100,000, which was higher in Non-Hispanic Whites (1099/100,000) compared with Non-Hispanic Blacks (324/100,000), Hispanics (383/100,000), and non-Hispanic Other (314/100,000). Relative to Non-Hispanic Whites, the odds ratios for having a diagnosis of IBD associated with being Non-Hispanic Black, Hispanic, and Other Non-Hispanic race after adjusting for age, sex, and geographic region were 0.33 (95% CI: 0.19 - 0.57), 0.45 (95% CI: 0.26 - 0.77), and 0.34 (95% CI: 0.12 - 0.93), respectively. IBD incidence was similarly lower in Non-Hispanic Blacks (24.9/100,000) and Hispanics (9.9/100,000) compared to Non-Hispanic Whites (70.2/100,000). The ratio of IBD hospitalizations to prevalence was disproportionately higher among Non-Hispanic Blacks (7.3%) compared with Non-Hispanic Whites (3.0%) and Hispanics (2.7%). Similarly, the ratio of IBD-related mortality was greater in Non-Hispanic Blacks (0.061%) compared to Non-Hispanic Whites (0.036%) and Hispanics (0.026%). CONCLUSIONS: IBD disease burden is lower in ethnic minorities compared to Non-Hispanic Whites. However, IBD-related hospitalizations and deaths seem disproportionately high in Non-Hispanic Blacks.

Do intensivist staffing patterns influence hospital mortality following ICU admission? A systematic review and meta-analyses.

OBJECTIVE: To determine the effect of different intensivist staffing models on clinical outcomes for critically ill patients. DATA SOURCES: A sensitive search of electronic databases and hand-search of major critical care journals and conference proceedings was completed in October 2012. STUDY SELECTION: Comparative observational studies examining intensivist staffing patterns and reporting hospital or ICU mortality were included. DATA EXTRACTION: Of 16,774 citations, 52 studies met the inclusion criteria. We used random-effects meta-analytic models unadjusted for case-mix or cluster effects and quantified between-study heterogeneity using I. Study quality was assessed using the Newcastle-Ottawa Score for cohort studies. DATA SYNTHESIS: High-intensity staffing (i.e., transfer of care to an intensivist-led team or mandatory consultation of an intensivist), compared to low-intensity staffing, was associated with lower hospital mortality (risk ratio, 0.83; 95% CI, 0.70-0.99) and ICU mortality (pooled risk ratio, 0.81; 95% CI, 0.68-0.96). Significant reductions in hospital and ICU length of stay were seen (-0.17 d, 95% CI, -0.31 to -0.03 d and -0.38 d, 95% CI, -0.55 to -0.20 d, respectively). Within high-intensity staffing models, 24-hour in-hospital intensivist coverage, compared to daytime only coverage, did not improved hospital or ICU mortality (risk ratio, 0.97; 95% CI, 0.89-1.1 and risk ratio, 0.88; 95% CI, 0.70-1.1). The benefit of high-intensity staffing was concentrated in surgical (risk ratio, 0.84; 95% CI, 0.44-1.6) and combined medical-surgical (risk ratio, 0.76; 95% CI, 0.66-0.83) ICUs, as compared to medical (risk ratio, 1.1; 95% CI, 0.83-1.5) ICUs. The effect on hospital mortality varied throughout different decades; pooled risk ratios were 0.74 (95% CI, 0.63-0.87) from 1980 to 1989, 0.96 (95% CI, 0.69-1.3) from 1990 to 1999, 0.70 (95% CI, 0.54-0.90) from 2000 to 2009, and 1.2 (95% CI, 0.84-1.8) from 2010 to 2012. These findings were similar for ICU mortality. CONCLUSIONS: High-intensity staffing is associated with reduced ICU and hospital mortality. Within a high-intensity model, 24-hour in-hospital intensivist coverage did not reduce hospital, or ICU, mortality. Benefits seen in mortality were dependent on the type of ICU and decade of publication.

Does implementation of a hospitalist program in a Canadian community hospital improve measures of quality of care and utilization? an observational comparative analysis of hospitalists vs. traditional care providers.

BACKGROUND: Despite the growth of hospitalist programs in Canada, little is known about their effectiveness for improving quality of care and use of scarce healthcare resources. The objective of this study is to compare measures of cost and quality of care (in-hospital mortality, 30-day same-facility readmission, and length of stay) of hospitalists vs. traditional physician providers in a large Canadian community hospital setting. METHODS: We performed a retrospective analysis of data from the Canadian Institute for Health Information (CIHI) Discharge Abstract Database, using multivariate logistic and linear regression analyses comparing performance of four provider groups of traditional family physicians (FPs), traditional internal medicine subspecialists (other-IM), family physician-trained hospitalists (FP-Hospitalist), and general internal medicine-trained hospitalists (GIM-Hospitalist). RESULTS: Compared to traditional FPs, FP-Hospitalists and GIM-Hospitalists demonstrate lower mortality [OR 0.881, (CI 0.779 - 0.996); and OR 0.355, (CI 0.288 - 0.436)] and readmission rates [OR 0.766, (CI 0.678 - 0.867); and OR 0.800, (CI 0.675 - 0.948)]. Compared to traditional FPs, GIM-Hospitalists appear to improve length of stay [OR-2.975, (CI -3.302 - -2.647)] while FP-Hospitalists perform similarly [OR 0.096, (CI -0.136 - 0.329)]. Compared to other-IM, GIM-Hospitalists have similar performance on all measures while FP-Hospitalists show a mixed impact. CONCLUSIONS: Compared to traditional family physicians, hospitalists appear to improve measures of quality and resource utilization. Specifically, hospitalists demonstrate lower in-hospital mortality and 30-day readmission rates while improving (or at least showing similar) length of stay. Compared to traditional subspecialists, hospitalists demonstrate similar performance despite looking after sicker and more complex medical patients.

Younger age and prognosis in diverticulitis: a nationwide retrospective cohort study.

BACKGROUND: Traditionally regarded as a disease of the elderly, the incidence of diverticulitis of the colon has been on the rise, especially in younger cohorts. These patients have been found to experience a more aggressive disease course with more frequent hospitalization and greater need for surgical intervention. OBJECTIVE: To characterize factors that portend a poor prognosis in patients diagnosed with diverticulitis; in particular, to evaluate the role of demographic variables on disease course. METHODS: Using the Canadian Institute for Health Information Discharge Abstract Databases, readmission rates, length of stay, colectomy rates and mortality rates in patients hospitalized for diverticulitis were examined. Data were stratified according to age, sex and comorbidity (as defined by the Charlson index). RESULTS: In the cohort ≤30 years of age, a clear male predominance was apparent. Colectomy rate in the index admission, stratified according to age, demonstrated a J-shaped curve, with the highest rate in patients ≤30 years of age (adjusted OR 2.3 [95% CI 1.62 to 3.27]) compared with the 31 to 40 years of age group. In-hospital mortality increased with age. Cumulative rates of readmission at six and 12 months were 6.8% and 8.8%, respectively. CONCLUSION: In the present nationwide cohort study, younger patients (specifically those ≤30 years of age) were at highest risk for colectomy during their index admission for diverticulitis. It is unclear whether this observation was due to more virulent disease among younger patients, or surgeon and patient preferences.

Trends in Canadian hospital standardised mortality ratios and palliative care coding 2004-2010: a retrospective database analysis.

BACKGROUND: The hospital standardised mortality ratio (HSMR), anchored at an average score of 100, is a controversial macromeasure of hospital quality. The measure may be dependent on differences in patient coding, particularly since cases labelled as palliative are typically excluded. OBJECTIVE: To determine whether palliative coding in Canada has changed since the 2007 national introduction of publicly released HSMRs, and how such changes may have affected results. DESIGN: Retrospective database analysis. SETTING: Inpatients in Canadian hospitals from April 2004 to March 2010. PATIENTS: 12 593 329 hospital discharges recorded in the Canadian Institute for Health Information (CIHI) Discharge Abstract Database from April 2004 to March 2010. MEASUREMENTS: Crude mortality and palliative care coding rates. HSMRs calculated with the same methodology as CIHI. A derived hospital standardised palliative ratio (HSPR) adjusted to a baseline average of 100 in 2004-2005. Recalculated HSMRs that included palliative cases under varying scenarios. RESULTS: Crude mortality and palliative care coding rates have been increasing over time (p<0.001), in keeping with the nation's advancing overall morbidity. HSMRs in 2008-2010 were significantly lower than in 2004-2006 by 8.55 points (p<0.001). The corresponding HSPR rises dramatically between these two time periods by 48.83 points (p<0.001). Under various HSMR scenarios that included palliative cases, the HSMR would have at most decreased by 6.35 points, and may have even increased slightly. LIMITATIONS: Inability to calculate a definitively comparable HSMR that include palliative cases and to account for closely timed changes in national palliative care coding guidelines. CONCLUSIONS: Palliative coding rates in Canadian hospitals have increased dramatically since the public release of HSMR results. This change may have partially contributed to the observed national decline in HSMR.