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Background: An efficient inventory control system would help optimize the use of resources and eventually help improve patient care. Objectives: The study aimed to find out the surgical consumables using always, better, and control (ABC) and vital, essential, and desirable (VED) technique as well as calculating the lead time of specific category A and vital surgical consumables. Methods: This was a descriptive, record-based study conducted from January to March 2016 in the surgical stores of the All India Institute of Medical Sciences, New Delhi. The study comprised all the surgical consumables which were procured during the financial year 2014–2015. Stores ledger containing details of the consumption of the items, supply orders, and procurement files of the items were studied for performing ABC analysis and calculating the lead time. A list of surgical consumables was distributed to the doctors, nursing staff, technical staff, and hospital stores personnel to categorize them into VED categories after explaining them the basis for the classification. Results: ABC analysis revealed that 35 items (14%), 52 items (21%), and 171 items (69%) were categorized into A (70% annual consumption value [ACV]), B (20% ACV), and C (10% ACV) category, respectively. In the current study, vital items comprised the majority of the items, i.e., 73% of the total items and essential (E) category of items comprised 26% of all the items. The average internal, external, and total lead time was 17 days (range 3–30 days), 25 days (range 5–38) and 44 days (range 18–98 days), respectively. Conclusions: Hospitals stores need to implement inventory management techniques to reduce the number of stock-outs and internal lead time.
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Lead time bias might exist in observational study for clinical outcomes.This paper summarizes the concept of lead time bias,causes and control of lead time bias by using the studies of influences of screening diagnostic test on cancer patients' survival and highly active antiretroviral therapy on HIV/AIDS patients' survival as examples for the purpose of providing thinking and methods in the control of lead time bias for the accurate evaluation of the effects of interventions,such as test and treatment,on the diseases with multi courses or phases.
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Lead time bias might exist in observational study for clinical outcomes.This paper summarizes the concept of lead time bias,causes and control of lead time bias by using the studies of influences of screening diagnostic test on cancer patients' survival and highly active antiretroviral therapy on HIV/AIDS patients' survival as examples for the purpose of providing thinking and methods in the control of lead time bias for the accurate evaluation of the effects of interventions,such as test and treatment,on the diseases with multi courses or phases.
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ABSTRACT Background. Evidence supporting benefit of hepatocellular carcinoma (HCC) surveillance in reducing mortality is not well-established. The effect of HCC surveillance in reducing mortality was assessed by an inverse probability of treatment weighting (IPTW)- based analysis controlled for inherent bias and confounders in observational studies. Material and methods. This retrospective cohort study was conducted on 446 patients diagnosed with HCC between 2007 and 2013 at a major referral center. Surveillance was defined as having at least 1 ultrasound test within a year before HCC diagnosis. Primary outcome was survival estimated using the Kaplan-Meier method with lead-time bias adjustment and compared using the log-rank test. Hazard ratio (HR) and 95% confidence interval (Cl) were computed using conventional Cox and weighted Cox proportional hazards analysis with IPTW adjustment. Results. Of the 446 patients, 103 (23.1%) were diagnosed with HCC through surveillance. The surveillance group had more patients with the Barcelona-Clinic Liver Cancer stage A (80.6% vs. 33.8%, P < 0.0001), more patients eligible for potentially curative treatment (73.8% vs. 44.9%, P < 0.0001), and longer median survival (49.6 vs. 15.9 months, P < 0.0001). By conventional multivariate Cox analysis, HR (95% Cl) of surveillance was 0.63 (0.45-0.87), P = 0.005. The estimated effect of surveillance remained similar in the IPTW-adjusted Cox analysis (HR: 0.57; 95% Cl: 0.43-0.76, P < 0.001). Conclusions. HCC surveillance by ultrasound is associated with a 37% reduction in mortality. Even though surveillance is recommended in all guidelines, but in practice, it is underutilized. Interventions are needed to increase surveillance rate for improving HCC outcome.
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Humanos , Carcinoma Hepatocelular/mortalidad , Carcinoma Hepatocelular/terapia , Carcinoma Hepatocelular/diagnóstico por imagen , Tailandia , Factores de Tiempo , Efecto de Cohortes , Modelos de Riesgos Proporcionales , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Ultrasonografía/normas , Guías de Práctica Clínica como Asunto , Medición de Riesgo , Estimación de Kaplan-Meier , Detección Precoz del Cáncer/métodos , Neoplasias Hepáticas/mortalidad , Neoplasias Hepáticas/terapia , Neoplasias Hepáticas/diagnóstico por imagen , Estadificación de NeoplasiasRESUMEN
Cancer screening evaluation will be a important issue in Korea in near future. Bias in cancer screening evaluation is well known by concept, but it is not applied yet using the data from screening program of Korea. So introducing the way how the bias is adjusted will be helpful. This review deals with the type, meaning, the way how the bias is adjusted, and examples. Especially, lead-time bias, length bias and self-selection bias were focused. Adjusting bias is one of the imperative step for epidemiologic analysis. Understanding the background concept and experience using the screening program data will be helpful for estimating the effectiveness of national screening program of Korea.