MEAN DELAY APPROXIMATIONS FOR POLLING SYSTEMS WITH BATCH POISSON INPUT

We study the expected delay in a cyclic polling model with mixtures of exhaustive and gated service in heavy traffic. We obtain closed-form expressions for the mean delay under standard heavy-traffic scalings, providing new insights into the behaviour of polling systems in heavy traffic. The results lead to excellent approximations of the expected waiting times in practical heavy-load scenarios and moreover, lead to new results for optimizing the system performance with respect to the service disciplines.

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Expected delay analysis of polling systems in heavy traffic

Advances in Applied Probability ◽

10.1239/aap/1035228085 ◽

1998 ◽

Vol 30 (2) ◽

pp. 586-602 ◽

Cited By ~ 11

Author(s):

R. D. van der Mei ◽

H. Levy

Keyword(s):

Heavy Traffic ◽

Waiting Times ◽

Delay Analysis ◽

Polling Systems ◽

Heavy Load ◽

Polling Model ◽

Mean Delay ◽

Service Disciplines ◽

The Mean ◽

Cyclic Polling

We study the expected delay in a cyclic polling model with mixtures of exhaustive and gated service in heavy traffic. We obtain closed-form expressions for the mean delay under standard heavy-traffic scalings, providing new insights into the behaviour of polling systems in heavy traffic. The results lead to excellent approximations of the expected waiting times in practical heavy-load scenarios and moreover, lead to new results for optimizing the system performance with respect to the service disciplines.

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THU0642-HPR EVOLUTION OF THE PERCEPTIONS OF RA PATIENTS AFTER EDUCATION PATIENT SESSION TEACHING METHOTREXATE SELF-INJECTION A PROSPECTIVE PILOT STUDY

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2020-eular.5505 ◽

2020 ◽

Vol 79 (Suppl 1) ◽

pp. 566.1-566

Author(s):

S. Afilal ◽

H. Rkain ◽

B. Berchane ◽

J. Moulay Berkchi ◽

S. Fellous ◽

...

Keyword(s):

Pilot Study ◽

Patient Education ◽

Median Duration ◽

Large Scale ◽

Education Session ◽

Prospective Pilot Study ◽

Mean Delay ◽

Lack Of Information ◽

Level Of Satisfaction ◽

Before And After

Background:Methotrexate is a gold standard for treatment of RA. In our context, RA patients prefer to be injected by paramedics rather than self-injecting. This can be explained by patients’ bad perceptions of self-injection or lack of information. Appropriate self-injection education can therefore be an important element in overcoming these obstacles and improving disease self-management.Objectives:Compare the RA patients’ perceptions on methotrexate self-injection before and after a patient education session.Methods:Prospective pilot study that included 27 consecutive patients (81.5% female, mean age 44.4 years, illiteracy rate 40.7%) with RA (median duration of progression of 4 years, mean delay in referral for specialist of 6 months, median duration of methotrexate use of 1 year). The patients benefited from an individual patient education session to learn how to self-inject with methotrexate subcutaneously. The patient education session was supervised by a nurse and a rheumatologist with a control a week later. Perceptions of the reluctance to self-inject and the difficulties encountered by patients were assessed before the patient education session, after the 1st and 2nd self-injection of methotrexate using a 10 mm visual analog scale. Patients also reported their level of satisfaction (10 mm VAS) after the 1st and 2nd self-injection.Results:The mean duration of patient education session is 13 min.Table I compares the evolution of the degrees of reluctance to self-injection, the difficulties encountered, and the satisfaction experienced by the patients.Table 1.Evolution of RA patients’ perceptions on the methotrexate self-injection. (N = 27)BeforeAfter the 1stself-injectionAfter the 2end self-injectionpVAS reluctance (0-10mm)6,5 ± 3,62,2 ± 2,91,0 ± 2,3<0,0001VAS difficulty (0-10mm)7,5 ± 2,62,5 ± 2,71,0 ± 1,9<0,0001VAS satisfaction (0-10mm)-8,9 ± 1,89,5 ± 1,50,002Conclusion:This study suggests the effectiveness of a methotrexate self-injection patient education session in RA patients. It also highlights the value of patient education in rheumatologic care. A large-scale study is necessary to better interpret and complete these preliminary results from this pilot study.Disclosure of Interests:None declared

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Clinical characteristics and outcome of hospitalized children and adolescent patients with type 1 diabetes during the COVID-19 pandemic: data from a single center surveillance study in Egypt

Journal of Pediatric Endocrinology and Metabolism ◽

10.1515/jpem-2021-0099 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Eman Monir Sherif ◽

Yasmine Ibrahim Elhenawy ◽

Randa Mahmoud Matter ◽

Hanan Hassan Aly ◽

Rasha Adel Thabet ◽

...

Keyword(s):

Type 1 Diabetes ◽

Pediatric Patients ◽

Surveillance Study ◽

Single Center ◽

Children And Adolescent ◽

Mean Delay ◽

Patients With Diabetes ◽

Constant Feature ◽

Inflammatory Syndrome

Abstract Objectives COVID-19 pandemic significantly impacted the diagnosis of type 1 diabetes and its acute complications. Thus, the study aimed to evaluate the characteristics of pediatric patients with type 1 diabetes hospitalized during the first wave of the pandemic and the prevalence of new onset diabetes among patients with evidence of COVID-19 infection. Methods A single-center surveillance study included all patients with diabetes admitted to Children’s Hospital, Ain Shams University, in Egypt between May to August 2020. Data were collected to evaluate patients’ clinical and laboratory characteristics as well as their outcomes. Results Thirty-six patients were admitted during the study period. The mean age was 8.4 ± 3.8 years. Patients presented late to the emergency department with a mean delay of 3.05 ± 1.19 days from onset of symptoms. 34/36 patients presented in diabetic ketoacidosis (DKA), 50% presenting in severe DKA. Almost 81% of the patients were newly diagnosed. During the study period, SARS-CoV-2 PCR was found positive in four patients, COVID Ig M antibodies were positive in another two patients; all were symptomatic requiring ICU admission. Four patients showed a picture suggestive of the multi-inflammatory syndrome (MIS-C); cardiac affection was a constant feature. Conclusions The pandemic affected both the prevalence and severity of DKA among pediatric patients. The increased prevalence of severe DKA could be partly related to delayed hospital admission or the effect of COVID-19 in triggering DKA. Efforts should be done to continuously raise awareness about diabetes in children as well as the importance of seeking timely medical guidance.

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Hand Infections: An Audit of 160 Infections Treated in an Accident and Emergency Department

Journal of Hand Surgery (European Volume) ◽

10.1016/0266-7681(93)90208-w ◽

1993 ◽

Vol 18 (1) ◽

pp. 115-118 ◽

Cited By ~ 16

Author(s):

J. STEVENSON ◽

I. W. R. ANDERSON

Keyword(s):

Emergency Department ◽

Complete Resolution ◽

Wound Care ◽

Duration Of Treatment ◽

Mean Delay ◽

Accident And Emergency ◽

Accident And Emergency Department ◽

The Mean ◽

Careful Assessment

160 consecutive hand infections presented to an Accident and Emergency department over a four-month period. All but one were treated solely on an out-patient basis. The mean delay to presentation was three days, the mean duration of treatment was six days. Follow-up to complete resolution was achieved in 89% of cases. No patients were treated with parenteral antibiotics. The need for careful assessment, early aggressive surgery, and meticulous attention to the principles of wound care by experienced clinicians is emphasized.

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Complex Regional Pain Syndrome: Current Practice Management and Referral Trends in a Closed Healthcare System

Osteology ◽

10.3390/osteology1010004 ◽

2020 ◽

Vol 1 (1) ◽

pp. 39-47

Author(s):

Connor Zale ◽

Joshua Hansen ◽

Paul Ryan

Keyword(s):

Pain Management ◽

Pain Score ◽

Complex Regional Pain Syndrome ◽

Healthcare System ◽

Pain Syndrome ◽

Occupational Outcomes ◽

Mean Delay ◽

Significant Difference ◽

The Mean ◽

Over Time

Background: Complex regional pain syndrome (CRPS) is a neurologic condition that can present with severe pain and dysfunction. Delay in treatment adversely affects outcomes. The purpose of this study is to evaluate patient outcomes as they relate to the time from diagnosis to pain management referral once the diagnosis of CRPS has been made in a closed healthcare system. Methods: A retrospective record review from a closed healthcare system was utilized for CRPS cases from 2010–2019. Demographics, injury pattern, surgeries, pain score, treatment modalities, occupational outcomes, and time to pain management referral were recorded. Results: There were 26 cases of CRPS that met inclusion criteria. The mean time from diagnosis to treatment was 55 days. 16/26 (61.5%) were medically discharged from the military. 23/26 (88.5%) were unable to return to full duty due to CRPS. There was no significant difference in the reported pain scores over time regardless of treatment (p = 0.76). A linear regression demonstrated a significantly higher Visual Analog Scale Pain Score (VAS) over time in patients that were medically discharged (p = 0.022). Conclusions: The mean delay in referral to the pain service was 55 days. The majority of patients (88.5%) did not return to full duty secondary to the diagnosis of CRPS, and 61.5% of patients required medical separation from active duty. Due to the negative impact that the diagnosis of CRPS has on occupational outcomes with a mean delay in referral of 55 days, clinics and providers should set up referral criteria and establish early pain pathways for patients diagnosed with CRPS.

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Tail Asymptotics for Monotone-Separable Networks

Journal of Applied Probability ◽

10.1017/s002190020011784x ◽

2007 ◽

Vol 44 (02) ◽

pp. 306-320

Author(s):

Marc Lelarge

Keyword(s):

Queueing Network ◽

Network Models ◽

Moment Generating Function ◽

Stochastic Petri Nets ◽

Arrival Process ◽

Polling Systems ◽

Tail Asymptotics ◽

State Variables ◽

Monotone Functions ◽

Jackson Networks

A network belongs to the monotone separable class if its state variables are homogeneous and monotone functions of the epochs of the arrival process. This framework contains several classical queueing network models, including generalized Jackson networks, max-plus networks, polling systems, multiserver queues, and various classes of stochastic Petri nets. We use comparison relationships between networks of this class with independent and identically distributed driving sequences and the GI/GI/1/1 queue to obtain the tail asymptotics of the stationary maximal dater under light-tailed assumptions for service times. The exponential rate of decay is given as a function of a logarithmic moment generating function. We exemplify an explicit computation of this rate for the case of queues in tandem under various stochastic assumptions.

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