Modeling and prediction of surgical procedure times

Accurate prediction of medical operation times is of crucial importance for cost efficient operation room planning in hospitals. This paper investigates the possible dependence of procedure times on surgeon factors like age, experience, gender, and team composition. The effect of these factors is estimated for over 30 different types of medical operations in two hospitals, by means of ANOVA models for logarithmic case durations. The estimation data set contains about 30,000 observations from 2005 till 2008. The relevance of surgeon factors depends on the type of operation. The factors found most often to be significant are team composition, experience, and daytime. Contrary to widespread opinions among surgeons, gender has nearly never a significant effect. By incorporating surgeon factors, the accuracy of out-of-sample prediction of case durations of about 1,250 surgical operations in 2009 is improved by up to more than 15 percent as compared to current planning procedures

Scoping review on health-related physical fitness in patients with inflammatory bowel disease:Assessment, interventions, and future directions

BACKGROUND:Reaching the Selecting Therapeutic Targets in Inflammatory Bowel Disease-II (STRIDE-II) therapeutic targets for inflammatory bowel disease (IBD) requires an interdisciplinary approach. Lifestyle interventions focusing on enhancing and preserving health-related physical fitness (HRPF) may aid in improving subjective health, decreasing disability, or even controlling inflammation. However, ambiguity remains about the status and impact of HRPF (i.e. body composition, cardiorespiratory fitness, muscular strength, muscular endurance, and flexibility) in IBD patients, hindering the development of physical activity and physical exercise training guidelines. AIM:To review HRPF components in IBD patients and the impact of physical activity and physical exercise training interventions on HRPF. METHODS:A systematic search in multiple databases was conducted for original studies that included patients with IBD, assessed one or more HRPF components, and/or evaluated physical activity or physical exercise training interventions. RESULTS:Sixty-eight articles were included. No study examined the complete concept of HRPF, and considerable heterogeneity existed in assessment methods, with frequent use of non-validated tests. According to studies that used gold standard tests, cardiorespiratory fitness seemed to be reduced, but findings on muscular strength and endurance were inconsistent. A limited number of studies that evaluated physical activity or physical exercise training interventions reported effects on HRPF, overall showing a positive impact. CONCLUSION:This review revealed a gap in the literature regarding the accurate assessment of HRPF in patients with IBD and highlighted important methodological limitations of studies that evaluated physical activity or physical exercise training interventions. Future well-designed studies are required to determine the optimal training paradigm for improving HRPF in patients with IBD before guidelines can be developed and integrated into the therapeutic strategy.</p

Enhancing customer experience through business process improvement : an application of the Enhanced Customer Experience Framework (ECEF)

In 2010 Botha, Kruger & De Vries [5] introduced a framework for enhancing customer experience through improved business processes. They developed the Enhanced Customer Experience Framework (ECEF) by integrating various well-known techniques into one comprehensive framework. The ECEF incorporates three well-known tools: quality function deployment (QFD), business process re-engineering, and simulation. QFD is used to determine the relationship beween business processes and customer requirements, and to prioritise business processes from a customer perspective. Business Process Re-engineering (BPR), together with the steps associated with benchmarking, provides a useful process that may be followed when re-engineering business processes to fit customer needs; while simulation modelling is used to test the impact of process improvements on customer experience. This paper aims partially to validate the ECEF against empirical data obtained from the telecommunications industry.’n Raamwerk om kliënte-ervaring te verbeter deur die herontwerp van besigheidsprosesse is in 2010 deur Botha, Kruger & De Vries [5] bekendgestel. Die verbeterde-kliënte-ervaring-raamwerk is ontwikkel deur welbekende tegnieke te integreer tot een omvattende raamwerk. Die verbeterde-kliënte-ervaring-raamwerk inkorporeer bekende tegnieke soos gehalte-funksie-ontplooiing, besigheidsprosesherontwerp en simulasiemodelering. Gehaltefunksie-ontplooiing word gebruik om die verhouding tussen besigheidsprosesse en kliëntebehoeftes te bepaal, asook om die prosesse te prioritiseer vanaf ’n kliëntperspektief. Besigheids-prosesherontwerp tesame met die stappe geassosieer met die gebruik van ’n verwysings-norm, bied ’n bruikbare proses wat gevolg kan word om besigheids prosesse te herontwerp om aan kliëntebehoeftes te voldoen. Simulasiemodelering kan vervolgens gebruik word om die impak van die prosesverbeteringe op kliënte-ervaring te meet. Hierdie artikel beoog om die verbeterde-kliënte-ervaring-raamwerk gedeeltelik te valideer deur die toepassing daarvan op empiriese data, verkry uit die telekommunikasie industrie.http://www.journals.co.za/ej/ejour_indeng.htm

The choline transporter Slc44a2 controls platelet activation and thrombosis by regulating mitochondrial function

Genetic factors contribute to the risk of thrombotic diseases. Recent genome wide association studies have identified genetic loci including SLC44A2 which may regulate thrombosis. Here we show that Slc44a2 controls platelet activation and thrombosis by regulating mitochondrial energetics. We find that Slc44a2 null mice (Slc44a2(KO)) have increased bleeding times and delayed thrombosis compared to wild-type (Slc44a2(WT)) controls. Platelets from Slc44a2(KO) mice have impaired activation in response to thrombin. We discover that Slc44a2 mediates choline transport into mitochondria, where choline metabolism leads to an increase in mitochondrial oxygen consumption and ATP production. Platelets lacking Slc44a2 contain less ATP at rest, release less ATP when activated, and have an activation defect that can be rescued by exogenous ADP. Taken together, our data suggest that mitochondria require choline for maximum function, demonstrate the importance of mitochondrial metabolism to platelet activation, and reveal a mechanism by which Slc44a2 influences thrombosis

Von Willebrand factor and ADAMTS13 activity in relation to risk of dementia

Low ADAMTS13 activity is associated with an increased risk of cardiovascular disease, which is generally attributed to its proteolytic effects on Von Willebrand factor (VWF). Cardiovascular health is an important determinant of cognitive decline, but the association of either VWF or ADAMTS13 with risk of dementia is unknown. Between 1997-2002, we measured VWF antigen and ADAMTS13 activity in 6055 participants of the population-based Rotterdam Study (mean age 69.3 years, 57.2% women). At baseline, 85 participants had dementia, and during 15 years of follow-up 821 developed dementia. Higher VWF was associated with prevalence and risk of dementia, unaffected by concurrent ADAMTS13 activity, but estimates strongly attenuated over time and were no longer statistically significant at 4 years of follow-up (relative risks [95% CI] per standard deviation increase- cross-sectional: 1.37 [1.06-1.77], and longitudinal: 1.05 [0.97-1.14]). In contrast, low ADAMTS13 was associated with increased risk of dementia throughout follow-up (hazard ratio per SD decrease- 1.16 [1.06-1.28]), which alike for ischaemic stroke, was modified by the presence of diabetes (P-interaction = 0.003). In conclusion, higher VWF and low ADAMTS13 activity are associated with increased risk of dementia, but differences in time-course and lack of synergistic effects may indicate in part independent underlying mechanisms

ADAMTS13 activity as a novel risk factor for incident type 2 diabetes mellitus: a population-based cohort study

Aims/hypothesis: ADAMTS13 is a protease that breaks down von Willebrand factor (VWF) multimers into smaller, less active particles. VWF has been associated with an increased risk of incident type 2 diabetes mellitus. Here, we determine whether ADAMTS13 activity and VWF antigen are associated with incident diabetes. Methods: This study included 5176 participants from the Rotterdam Study, a prospective population-based cohort study. Participants were free of diabetes at baseline and followed up for more than 20 years. Cox proportional hazards models were used to examine the association of ADAMTS13 activity and VWF antigen with incident diabetes. Results: ADAMTS13 activity was associated with an increased risk of incident diabetes (HR 1.17 [95% CI 1.08, 1.27]) after adjus

Prognostic Value of the Modified Rutgeerts Score for Long-Term Outcomes After Primary Ileocecal Resection in Crohn’s Disease

IntroductionThe prognostic value of the modified Rutgeerts score (mRS) in patients with Crohn's disease (CD) needs to be further elucidated. This study assessed the prognostic value of the mRS for long-term outcomes after primary ileocecal resection in patients with CD.METHODS: Patients with CD after primary ileocecal resection with an available mRS at first postoperative ileocolonoscopy (index mRS) were retrospectively included. The primary outcome was surgical recurrence. Secondary outcomes were clinical recurrence and progression to severe endoscopic recurrence (‡i3). Cox proportional hazard models were used to assess the association between index mRS and outcomes. RESULTS: Six hundred fifty-two patients were included (mean follow-up: 6.4 years, SD: 4.6). Surgical recurrence rates were 7.7%, 5.3%, 12.9%, 19.1%, 28.8%, 47.8% for index mRS i0, i1, i2a, i2b, i3, and i4, respectively. Clinical recurrence occurred in 42.2% (i0), 53.7% (i1), 58.5% (i2a), 80.2% (i2b), 79.4% (i3), and 95.3% (i4) of patients. Progression to severe endoscopic recurrence occurred in 21.1% (i0), 33.9% (i1), 26.8% (i2a), and 33.3% (i2b) of patients. An index mRS of i2b (adjusted hazard ratio [aHR] 3.0; 1.5–5.6), i3 (aHR 4.0; 2.0–7.9) and i4 (aHR 8.0; 4.0–16.0) were associated with surgical recurrence. An index mRS of i1 (aHR 1.7; 1.2–2.4), i2a (aHR 1.7; 1.2–2.4), i2b (aHR 4.4; 3.2–6.0), i3 (aHR 3.6; 2.5–5.2), and i4 (aHR 7.3; 4.8–10.9) were associated with clinical recurrence. An index mRS of i1 (aHR 2.0; 1.1–3.7) or i2b (aHR 2.5; 1.4–4.6) was associated with progression to severe endoscopic recurrence.DISCUSSION: The increasing mRS corresponds closely with the risk of surgical and clinical recurrence. An index mRS ‡ i2b is associated with surgical recurrence, an index mRS ‡ i1 is associated with clinical recurrence, and i1 or i2b with progression to severe endoscopic recurrence. These results support tight monitoring of disease activity and treatment optimization in patients with ileal lesions and a more conservative management in patients with anastomotic lesions.</p

Prognostic Value of the Modified Rutgeerts Score for Long-Term Outcomes After Primary Ileocecal Resection in Crohn’s Disease

IntroductionThe prognostic value of the modified Rutgeerts score (mRS) in patients with Crohn's disease (CD) needs to be further elucidated. This study assessed the prognostic value of the mRS for long-term outcomes after primary ileocecal resection in patients with CD.METHODS: Patients with CD after primary ileocecal resection with an available mRS at first postoperative ileocolonoscopy (index mRS) were retrospectively included. The primary outcome was surgical recurrence. Secondary outcomes were clinical recurrence and progression to severe endoscopic recurrence (‡i3). Cox proportional hazard models were used to assess the association between index mRS and outcomes. RESULTS: Six hundred fifty-two patients were included (mean follow-up: 6.4 years, SD: 4.6). Surgical recurrence rates were 7.7%, 5.3%, 12.9%, 19.1%, 28.8%, 47.8% for index mRS i0, i1, i2a, i2b, i3, and i4, respectively. Clinical recurrence occurred in 42.2% (i0), 53.7% (i1), 58.5% (i2a), 80.2% (i2b), 79.4% (i3), and 95.3% (i4) of patients. Progression to severe endoscopic recurrence occurred in 21.1% (i0), 33.9% (i1), 26.8% (i2a), and 33.3% (i2b) of patients. An index mRS of i2b (adjusted hazard ratio [aHR] 3.0; 1.5–5.6), i3 (aHR 4.0; 2.0–7.9) and i4 (aHR 8.0; 4.0–16.0) were associated with surgical recurrence. An index mRS of i1 (aHR 1.7; 1.2–2.4), i2a (aHR 1.7; 1.2–2.4), i2b (aHR 4.4; 3.2–6.0), i3 (aHR 3.6; 2.5–5.2), and i4 (aHR 7.3; 4.8–10.9) were associated with clinical recurrence. An index mRS of i1 (aHR 2.0; 1.1–3.7) or i2b (aHR 2.5; 1.4–4.6) was associated with progression to severe endoscopic recurrence.DISCUSSION: The increasing mRS corresponds closely with the risk of surgical and clinical recurrence. An index mRS ‡ i2b is associated with surgical recurrence, an index mRS ‡ i1 is associated with clinical recurrence, and i1 or i2b with progression to severe endoscopic recurrence. These results support tight monitoring of disease activity and treatment optimization in patients with ileal lesions and a more conservative management in patients with anastomotic lesions.</p