Estimating Blood Need and Planning

One of the most important essential first move for blood donor recruitment is establishing clear goals by estimating pragmatically the blood need of the Country/State/Region/ Blood Bank. For a well established transfusion service, with a long history of success, knowledge of current patterns of blood usage and data of changes from year to year, it is a straightforward matter to project need into the future, to plan blood collection and recruit donors accordingly.The process is much more difficult at the beginning in regions or states where no data is available for any estimation at all. It is, therefore, quite natural that maiden attempts of donor recruitment may result in insufficient blood collection in reality. Surrounding every mountain peak, there are valleys and into these valleys one must go before climbing the peak. There are joys. There are disappointments. There will be success and there will be failure. Blood donor motivators should have a mental makeup to accept both the rough and the smooth. The journey of a thousand miles begins with the first step. And, a beginning has to be made.There may be three principal reasons for failure in the first venture:

  • Immature organisation
  • Lack of clear goals
  • Underestimation of blood need.

When there is no blood, suppressed need of blood would not come to the surface. Blood need will increase with the availability of blood. Even donor awareness campaigns may inculcate the sense of need of blood in the minds of the clinicians and surgeons resulting in irrational use of blood. That should be taken care of when blood would become easily available from the blood banks.There may be a number of approaches for the estimation of blood need. Some are simple and some are complex in character. Some may give an approximate idea and some may give a fairly accurate target. To start with a goal, however approximate, a target is badly needed to set the ball rolling.There are four approaches to estimate how much blood is needed:

  • In relation to hospital beds
  • In relation to total population
  • In relation to medical facility available in the region
  • In relation to past blood usage.

Ideally, if 2% of population donates blood, it will be more than sufficient to meet the need of a country like India. For a population of 100 crores (1000 million), 2 crores (20 million) of intending blood donor would be more than sufficient for the country by taking into consideration all possible allowances. The present estimated blood need of India is 80 lakh (8 million) units. In the first method the need of blood can be calculated as 3 to 15 units per hospital bed per year. It may also be calculated as 7 to 20 units per acute hospital bed per year. In the primary health centres, the need may be 3 units per bed per year, while at a super speciality surgical hospital the need may be as high as 25 - 30 units /bed /year. The golden mean may be worked out. With the introduction of open heart surgeries, liver transplants and treatment for oncological disorders in the country, the need  of blood in different regions have increased.

The table below indicates the enormous variations of blood donor per 1000 population between different countries.
Switzerland   113    Japan    70    Australia    58
New Zealand  56    Canada    55    UK    40
Greece         33    Singapore    24    Macao    23:
Hongkong   27    Korea    22    Spain    21
Jordan         17    Malaysia    13    Zimbabwe    10
Mexico         10    New Guinea    9    Fiji    9
Philippines  7    China    4    Brazil    2
Vietnam    2    Sudan    2    Ethiopia    0.4
In India, this figure at the moment is 4 per thousand population with
some regions/states at a higher than the national average and some below
the national average.If this national average can be raised to 8 voluntary blood donor per 1000 population, there would not be any shortage of blood for the country and none would die for want of blood for transfusion.

The ideal simple method of estimating blood need at the beginning would be to make a list of hospitals together with the details of bed strength of a region for which a particular blood bank or transfusion service is supposed to cater. This data is available with the health authority of the state. From this data, by counting the actual bed or acute bed, by using rule of thumb, blood need can be calculated by multiplying by the  appropriate factor between 3 and 20 depending upon the standard of the health service. Another method may be to collect data about the requisitions received and served by the blood bank / transfusion service over a period of not less than three months. If such study had been conducted in the past, the results should also be studied. While computing such data, care should be taken pragmatically to:

  • Express all data on annual basis (if information availability covers only three months, it should be multiplied by four).
  • If data are not up-to-date, there should be interpolation and or extrapolation to allow for changes during the intervening period.
  • It should be ascertained that information collected is, in fact complete.
  • Inconsistency between blood collection and blood usage should resolved before interpretation.

It will be difficult to get data in many states due to poor documentation and improper record keeping system. Still a survey has to be undertaken. The survey may be based on the following questionnaires

  • How many units of blood are collected by the hospital in day/ week/month/year?(any one)
  • How many requisitions are received in a day/week/ month/year? (any one)
  • How many units are asked for on an average per requisition?
  • Whether blood for the patients are obtained from other sources?
  • If so, what is the quantum?

With these data, blood need can be estimated for the state/region/ blood bank for the year.The motivators have to collect another set of data i.e. actual storage capacity of blood bank(s) or transfusion service for which blood donor recruitment is being planned.
The blood donor motivators should remember that the donor recruitment target should always be higher than the estimated blood need.
The reasons are :

  • Recruited donor may not turn up on the day of blood collection.
  • Intending donor may be temporarily deferred on medical reasons at the time of actual blood collection.
  • Collected blood after testing may be discarded for containing blood communicable parasite/virus.

Further, to meet each and every blood need, the services will have to stock blood more than the estimated requirement. As it is not known from which blood group patients would come, blood of all groups including rare groups is to be adequately stocked. There may be some marginal periodic so-called ‘wastage’ due to out dating of blood of some groups. A question can be raised: which is better, some one dying for want of right group of blood or some blood bags being discarded after the prescribed expiry period for want of requisition of that particular group?


How do we feel if the unfortunate victim, whose blood need could not be met, is our near and dear one?
A small portion of the collected blood, about 5%, may be outdated, another portion of about 1% may be discarded after testing, for various reasons. Some of the intending donors may be deferred on medical reasons; some intending donors may not turn up on the date and time of blood collection. Considering all these allowances and adding a blanket allowance of further 10%, the target of donor recruitment may be planned for the year and computed for month or week.
Target of donor recruitment, annually, monthly or weekly should be at the finger tip of donor recruiters. A portion of blood would be collected in the blood bank but a goal has to be set. The goal should be pragmatic Estimation of blood need and planning the target of blood donor recruitment are the initial steps to identify the goal. The donor motivators/recruiters should assess, review and reset the goal from time to time by generating data from different sources