National preventive vaccination in the best order quantity and distribution pattern - the Taipei County
Health Bureau of DPT vaccine as an example Long before Zhan Shen Sheng Yuan 1 1 1 Limeng Yu Qiu Yan
Zhejie Ruike 2 4 3 The Feature
1 Institute of Information Management Yuan Ze University, 2 Institute of Information Management Fu Jen Catholic University
3 Department of Health, Center for Disease Control Vaccination 4 head of the Department of Health Information Director of the Center
for Disease Control
clchan@im.yzu.edu.tw Summary
This study investigated the national preventive vaccination of the best order quantity model to time series method to estimate next year's vaccination target population and vaccination completion rates. Another method of linear
programming, then get the vaccine between clinic scheduling and order quantity.
Taipei County Health Bureau of the diphtheria-tetanus pertussis vaccine (DPT), for example, in order to consider vaccine targets and constraints, the decision to purchase the vaccine and the number of clinic scheduling and allocation of the amount of vaccine. The estimated data can be used as a national budget for vaccine procurement operations reference, has the following three benefits: (1) effective control of vaccine inventory, reduce unnecessary inventory costs, improve quality and promote use of effective vaccines. (2) support the national policy for vaccines single dose, multiple doses of the basis for the development and effective saving of funds (3) scientific method to estimate the distribution of vaccines throughout the quantity, the effective deployment of vaccine purchase amount.
Keywords: vaccine procurement, forecasting, time series analysis, linear programming
Abstract
This study aims to find out the optimum purchase strategy of vaccines, which means lowest cost, lowest inventory and lowest waste. This study applied Time Series Analysis to forecast the population size of new born babies and the total vaccines needed. After that, the amount of vaccines to be dispatched to each public health bureau was calculated by Integer Programming. These approaches will have the following advantages. First, CDC will be able to control the total stock of vaccines to avoid unnecessary expenditure of inventory cost. Second, an optimum combination of single-dose vaccines and multiple-dose vaccines can save the cost. Third, the dispatch model among the public health bureaus will assure the sufficient supply and quality of vaccines.
Keyword: Vaccine purchase,Forecast, Time Series Analysis, Linear Programming
1. Introduction
First, the importance of infant vaccination
Vaccination is everyone is born to be experienced, it can avoid infections and reduce deaths, all in the most cost-effective public health "investment"
[10,12,14]. Vaccine immunization timely manner, can effectively prevent infectious diseases, prevention of disease outbreaks, save a lot of medical resources, with significant social and economic benefits. [13] by vaccination in Taiwan to achieve effective control or even eradicate the disease examples, including smallpox, rabies, diphtheria, tetanus, pertussis, polio, Japanese
encephalitis, measles, mumps, rubella, B and hepatitis tuberculosis [3]. By the
vaccination history, you can obviously see that Taiwan has actively pursued after immunization, many diseases can be eradicated in the short term or significantly reduce the incidence and mortality, and because the complete implementation of the vaccination, Taiwan top ten causes of death are communicable diseases mainly from the original type of disease to cancer and chronic diseases in elderly men, the average female life expectancy increased to 72 years old, 78 years, universal vaccination is indeed a hero. So how to make the universal vaccination, but disease control priority.
In the implementation of vaccination policies, how objective and scientific way of making purchases of the vaccine is a subject worth exploring. The Executive Yuan for Disease Control Council (CDC) in determining the amount of the national vaccine procurement, due to lack of computerization of the health center data and compile information flow is not easy, not try to quantify and forecast model to estimate the amount of vaccine Instead, the value of historical experience with the population growth factor to determine the annual amount of the vaccine
procurement, in this case likely to cause the number of excess or shortage of the vaccine situation, also resulted in vaccine management difficulties. According to Ukraine's national pre-estimate trends in types of units, the future use of the vaccine, the use of multi-dose vaccine will be increased significantly. Because of multi-dose vaccine is the advantage of lower cost, but will also result in multi-dose vaccine, "Vaccine wastage rate" problem, which leads to wastage of funds [8]. In
addition, the CDC on the local health authorities in vaccine distribution volume, the historical rule of thumb is to take the decision. Easily lead to a clinic out of stock, while the other clinic was too much inventory, and may result in excessive inventory costs and doubts about the vaccine expired. Therefore, how to reduce the cost of the considerations in the most appropriate amount of purchase orders, multi-dose vaccine, and decided over the amount of vaccine distribution and scheduling is an issue worth exploring. As the Windows version of the national vaccination implementation of a central database is not long, the factors based on data obtained in this study under the jurisdiction of the Taipei County Health Department immunization clinic information for the study, and the first to diphtheria tetanus pertussis vaccine (DPT ) the study.
Second, NIIS Introduction
82 Department of Health in the Republic of China began promoting the "National Health Information Network", the development of a range of health and medical information systems. Medical information to the exchange and transfer through the network to promote information flows more quickly, but also bring a lot of growth data. 90 years of vaccination in order to establish a national database and network services system, to be combined with the original health stations and immunization Subsystem (PHIS), the use of modern network infrastructure to provide timeliness and integrity of the database management and network services. NIIS (National Immunization Information System) system, but the CDC commissioned the Institute for Information Industry will conduct planning and design of a new generation of national immunization information system [1,2], information on the Republic of China by the Fujitsu 91 system implementation started in early, early in the 92 national comprehensive import, system
implementation has been completed by the end in 92 national and 25 local health bureaus and township health centers and 374 medical and 600 pilot into the clinic. It is inherited mainly used in the past at the grassroots level PHIS (Primary Health Information System) system contained in the subsystem of vaccination, and for systemic, functional upgrading and improvement of processes, and to the
implementation of Web technology and systems environment as the basis for system design [4,5]. NIIS medical information systems through the backbone network and the Interior Ministry of Health household population database link, the Bureau and agreement around the local health care institutions are
transmitted to integrate immunization data, by the Central Database of vaccination and decision support auxiliary system to achieve the overall objectives of vaccination management [6,7].
Third, vaccine demand forecasting annual procurement information
Demand for the vaccine dosage calculation itself is a complex issue. So here
the first vaccine against may affect the amount of demand factors, there are many uncertain factors that can influence the amount of the relevant factors, such as Table 1.
Table 1 Factors affecting vaccine dosage
Factor name Explain
Vaccination completion rate
Important factors
determine the demand for the vaccine vaccination completion rate, completion rate is defined as the completion of vaccination in the period the total number of the ratio of the number to be inoculated.
Do the required number of doses of vaccine inoculation
Non-vaccine types were only injected with one dose, some vaccines such as tetanus pertussis vaccine white cough be injected with more than one.
Target
population size
General routine
vaccination for infants or newborns object, then the size of the target population
to be considered shall be the number of births per year.
Vaccine wastage rate
Vaccine wastage due to loss of temperature caused by the proportion of the total number of vaccines.
Keep inventory Not for lack of vaccination on, different vaccines in the country must have at least a different stocks, known as
"safety stock", so, consider vaccine order quantity must be for the "reserve stock" to consider.
Multi-unit single- dose vaccine
For single-unit multi-dose vaccine is different from the procurement is an
important factor, when we want to save costs, you need to consider the unit cost.
One more dose of vaccine
procurement ratio
Based on the price of a single multi-dose vaccine with different capacity, how to determine the
appropriate procurement ratio is an important issue.
The proportion of the workload of Health
Workload of the Health Board shall be the workload of vaccination, this factor is distribution of vaccines to the Health Bureau of the important indicators.
Around the characteristics of
For in the mountains or the less populated areas, if
given "multi-dose vaccine,"
would increase the depletion rate of the vaccine. Therefore, for these areas, just to give "a single dose of vaccine," can be.
Two, the research methods First, research framework
This study from the Health Department point of view, and consider the various clinics between vaccine stocks can support each other's environment to minimize procurement costs and the lowest inventory of considerations, calculate the health required to host the next period required by the Taipei County Health Bureau vaccine type and relative numbers, then that Taipei County Health Bureau in the next period to be more than a single dose of vaccine procurement volume.
Research framework shown in Figure 1. Model established based on the following assumptions: 1. The clinic flow between the vaccine each other, support each other enough vaccine to public health 2. In cross-clinic planning model will not consider the vaccine procurement, distribution and other operations required lead time 3. assumes that once the clinic decided to vaccine procurement, distribution and other operations, the vaccine can be delivered beginning in the planning, without the use of the completed section will be treated as inventory 4. The Health Department procurement cost of the vaccine are known 5. the health center asked the central distribution occurs when the setup cost vaccine known 6.
The cost of the vaccine are known to store health clinics 7. between the various clinics due to lack of mutual support vaccine it takes the transportation cost of the vaccine are known. Analysis of data sources in this case mainly in Taipei County, 29 health centers NIIS database of relevant information, and calendar information related to population census from the Ministry of the Interior to obtain chronology.
Second, the number of model building Variable definition:
Model Parameters:
Description of decision variables:
Target type and constraints
Parameters, results
This study is a pilot study, only select the diphtheria, pertussis, tetanus (DPT) empirical study, prediction models as the precursor of other experimental vaccines. As the current annual vaccine procurement for the procurement of vaccine-associated information to plan over the years in the Republic of China, Taipei County Health Bureau, 91 procurement, distribution and scheduling vaccine. According to CDC report recommends, DPT vaccine at least three vaccination antibody can be effectively obtained. Keep inventory parameter settings, mainly interviews with CDC vaccine procurement manager in charge, according to China in the procurement of vaccines, usually to buy 3 months of vaccine requirements and to prepare for future uncertainties occur. In this 3
months into an annual basis when compared to 25% months. Therefore, this study will be retained parameter is set to 25%.
1, Taipei County newborn population
The variables affecting the amount of the vaccine, such as the number of newborn vaccination completion rates, number of doses of vaccine do not have vaccination and reserve inventory to estimate the DPT vaccine next year, Taipei County, the total demand. Data sampling time range of 70 to 91 years of the Republic of China, Taipei County, the number of birth information to the Republic of China 70 years to 90 years of training materials for the prediction model.
According to RMSE error standard, the Alpha and Beta for the 0.736 and 0.025 of the state to Double Exponential Smoothing method of prediction error minimum [9,11].
91-year forecast of the Republic, Taipei County birth number is 38,359.
2, Taipei County, to complete DPT vaccination rate forecast
The completion rate is defined as a before and after the scheduled time of 30 days to complete the total number of vaccination should be vaccinated ratio.
Through NIIS system BAB2 and BAC1 table extracted from 84 years to 90 years Republic of China, Taipei County, the DPT vaccination completion rate over the years. According to RMSE error standard, vaccination completion rate of the prediction method to the Alpha Beta of 0.001 and 0.001 of the state to Double Exponential Smoothing is most accurate. 91 Republic of China, Taipei County forecast DPT vaccination completion rate of 81%.
3, Taipei County, the clinic alone, estimates the number of multi-dose vaccine
Single, multi-dose vaccine purchase price variables are taken to the Republic of China 91 years, the CDC in the procurement of a single dose of DPT vaccine and multiple doses of vaccine, one dose of vaccine is priced at 31.37 yuan, multi-dose vaccine is priced at 7.44 yuan. In practice, the proportion of single multi-dose vaccine procurement, procurement of vaccines the CDC unit based primarily on the expertise of a single unit and multi-dose vaccine to buy properties around the inoculum determined. According to interviews with the CDC vaccine procurement unit, the expert in this study to determine the weights of the various health centers, the proportion of single multi-dose purchases. For example: a single dose of vaccine a unit price 31.37 yuan, multi-dose vaccine a 7.44 yuan.
However, a multi-dose vaccine after opening if not used up is deemed abandoned.
As more vaccine doses can be diluted 20 bottle of vaccine, if not vaccinated 20 times, it must be discarded. Consider the cost of the vaccine, more than one dose of vaccine use must be vaccinated more than five people meet the cost (7.44 * 20/31.37 = 4.2), without any wastage. Therefore, if a vaccination clinic on average more than 5 people per day, of this clinic is to set a single multi-dose vaccine procurement ratio of 1:1. If the number of day not more than five persons inoculated, then set this clinic more than a single dose of vaccine
procurement ratio of 1:0. Vaccine wastage rate in Taipei County, according to the current use of a single dose of vaccine and the vaccine produced by multi-dose vaccine wastage data. According to interviews, the CDC recommended the vaccine procurement unit depletion rate of single-dose vaccine is set to 0%, while the multi-dose vaccine wastage rate parameter is set to 50%.
4, Taipei County, health stations and inter-clinic planning model vaccine
Table II, if adopted, Taipei County, the best order quantity model across the whole vaccination clinic planning model, you can learn DPT vaccine ordering, allocation and scheduling when the total cost of about 987,010.33 dollars.
Including the purchase of a single dose of vaccine costs 242,458.73 dollars, multi- dose vaccine purchase cost 715,281.6 yuan, the vaccine distribution to health clinics Health action 26 times, cost 26,000 yuan, due to higher safety stock closing stocks resulting from multiple doses of vaccines Cost 150. Mutual
support between clinic vaccine vaccine transport movements that occur 29 times, according to another freight between the different clinics, plus the total of all transportation costs, costs 3,120 yuan.
If not the best order quantity model with cross-overall vaccination clinic planning model, the Taipei County health clinics unable to integrate the various clinics within the vaccine stocks, and vaccines can not be the redistribution of resources.
If the cost calculation according to the vaccine, the vaccine can be ordered at that time, Taipei County, the total cost of 1,077,898.07 dollars. Including the purchase of a single dose of vaccine costs 297,105.27 dollars, multi-dose vaccine purchase cost 722,572.8 yuan, the health bureau to vaccine distribution to health centers, a total of 38 action, cost 38,000 yuan, due to higher safety stock end of stocks caused by a single dose of vaccine stocks cost of 17,620 yuan, due to higher safety stock end of stocks caused by more than 2,600 doses of vaccine inventory costs, because the clinic can not provide mutual support to each other between the vaccine, vaccine transport costs 0.
Table 2 The cost of using the mode or form
The cost of the project Adoption Model
Not use
mode Difference
Purchase cost of a single
dose of vaccine 242,458.73
297,105.27
54,646.54
Purchase cost of multi- dose vaccine
71,5281.6 722,572.8 7291.2
Health Department allocated the vaccine to the clinic set-up costs arising from
26,000 38,000 12,000
More than a single dose of 0 17,620 17,620
vaccine safety stock inventory inventory costs caused
Multi-dose vaccine over safety stock inventory inventory costs caused
150 2,600 2,450
Supporting other clinics because of transportation costs caused by
3,120 0 -3,120
Total cost
987,010.331,077,898.0 7
90,887.74
Therefore, if the Taipei County Health Bureau to take the overall vaccination clinic planning model across in 91 years of the Republic of China, Taipei County Health Bureau to take into account the needs of the clinic and reach full use of the vaccine and the premise of reducing inventory costs can reduce the cost of 90,887.74 dollars. Reduction of approximately 8.4% of the costs. Reduce these costs, mainly due to the effective use of vaccine, the vaccine reduced inventory costs and can provide mutual support between clinic because of the result caused by the lower purchase cost of the vaccine.
Wantonly, conclusions and recommendations
This study operations research linear programming, in order to consider the total cost of the vaccine target and the minimum order requirements and scheduling constraints, the health clinic for a variety of vaccines derived from each quantity and the scheduling occurs when the amount of vaccine delivery . The future, if integrated into NIIS systems will be able to effectively help manage vaccine ordering vaccine makers planning, allocation and scheduling action, and can be integrated into the clinic vaccine resources to reallocate resources, to achieve the effective use of vaccines and reduce the effectiveness of vaccine stocks.
Expected benefits of consolidation are as follows:
1. Institute estimated the national vaccine procurement data can be used as a reference operating budget, in order to effectively control vaccine
inventory, reduce unnecessary inventory costs, improve quality and increase the use of vaccine effectiveness.
2. According to vaccine procurement decision-making model to formulate a national vaccine procurement recommended amount, effectively saving the cost of vaccine procurement.
3. To health centers around the scientific method to estimate the amount of vaccine distribution, the effective deployment of vaccine purchase amount.
Acknowledgements
In this study, pre-species group of Sending Thank CDC chief and Taipei County Health Bureau offers a number of vaccine procurement expertise and valuable advice. CDC Pre-species group, Fujitsu DPT Vaccination Information provided historical information to make vaccine procurement model can be established and verified.
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