Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contacts Login 
  • Users Online:515
  • Home
  • Print this page
  • Email this page

 Table of Contents  
Year : 2019  |  Volume : 4  |  Issue : 1  |  Page : 52-57

Revisit of efficiency of blood usage – Need for continuous audit

1 Department of Transfusion Medicine, St. John's Medical College, Bengaluru, Karnataka, India
2 Department of Transfusion Medicine and Immunohematology, St. John's Medical College, Bengaluru, Karnataka, India

Date of Web Publication22-Apr-2019

Correspondence Address:
Dr. Sitalakshmi Subramanian
Department of Transfusion Medicine and Immunohematology, St. John's Medical College, Bengaluru, Karnataka
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/GJTM.GJTM_12_19

Rights and Permissions

Background: The most common indices assessing blood usage are crossmatch-to-transfusion (C/T) ratio, transfusion probability (%T), Transfusion Index (TI), nonusage probability (NUP), and wastage as percentage of issue (WAPI). This study, in a South Indian tertiary care hospital, audits blood utilization efficiency and revisits it after implementing corrective measures for deficiencies identified by the first audit highlighting the importance of continuous surveillance and proper measures in efficient blood utilization. Materials and Methods: Blood utilization over 6 months, assessed by C/T ratio, TI, %T, and NUP indicated inefficient blood usage (high C/T ratio). After initiating appropriate measures, reaudit over 1 month assessed effect on blood usage. The total duration was from December 2017 to November 2018. Request forms packed red blood cells provided patient demographics, number of units requested, and indication. Blood bank records provided number of units crossmatched and issued against each request. Results: Initial audit: total requests- 4450, C:T ratio-3.6, TI-0.5, %T- 32% and NUP- 72%. Reaudit: Total requests-948 (medical 52%, surgical 48%), Overall monthly WAPI- 0.1%, C:T ratio-2.4 (medical 1.3, surgical 3.5), %T-63.5%(medical 84%, surgical 43%), TI-1 (medical 1.4, surgical 0.6), NUP- 24% (medical- 11%, surgical 37%) C/T ratio – no subspecialty crossed the highest acceptable value (2.5) except gynecology and obstetrics (4.1) and pediatric surgery (2.75). All departments met the lowest acceptable %T (30%) except G&O (25.2%). All departments met minimum TI (0.5) except G&O (0.3), pediatric surgery (0.47), and surgical super specialties (0.3). Conclusion: Initial audit showed inefficient blood utilization. Appropriate steps taken to improve this included the establishment of standard protocols. Reaudit showed efficient blood utilization in medical departments and the need for further revision in practices for surgical departments. Hence, continuous monitoring is vital in ensuring effective blood usage.

Keywords: Audit, blood utilization, indices

How to cite this article:
Banerjee S, Puttaiah P, Subramanian S. Revisit of efficiency of blood usage – Need for continuous audit. Glob J Transfus Med 2019;4:52-7

How to cite this URL:
Banerjee S, Puttaiah P, Subramanian S. Revisit of efficiency of blood usage – Need for continuous audit. Glob J Transfus Med [serial online] 2019 [cited 2020 Aug 9];4:52-7. Available from: http://www.gjtmonline.com/text.asp?2019/4/1/52/256737

  Introduction Top

Blood and blood products are the mainstay of therapy in many situations. However, every transfusion is associated with risks such as transfusion-transmitted infections and transfusion reactions; however, minimal the chances may be. Hence, it can be said, no transfusion is the best transfusion. On the other hand, crossmatching of blood and blood products means increase in turnaround time for blood issue, increased cost to patients, and unavailability of those units for other patients.[1] Hence, requesting and utilizing of blood and blood products have to be optimized, since blood is a precious resource.

As such, both the clinician and the transfusion specialist have important roles to play in this regard. One of the first things for transfusion services to do is to monitor the usage of blood and blood products. The evaluation of blood utilization practices is the first step toward the formulation of appropriate guidelines for blood ordering. The role of regular audit in identification of ineffective blood usage cannot be overstressed. There are certain indices that are used for such audits. Henry Boral defined crossmatch-to-transfusion (C/T) ratio in 1975. Since then, it has been widely used to monitor efficacy of blood usage. A few other indices such as transfusion probability (%T)[2] and Transfusion Index (TI) have also been described since. Newer indices such as nonusage probability (NUP)[3] and wastage as percentage of issue (WAPI)[4] have also been defined.

Recommended steps to address any lapses in blood utilization practices and policies thus identified include interdepartmental meetings and staff training in addition to regular transfusion committee meetings. A close monitoring of the effectiveness of any implemented measure, also by regular audit, ensures effective blood usage.

Our study used a novel approach of monitoring the usage of red blood cells (RBCs) over 6 months using four indices and identifying the lapses in RBC utilization practices; we addressed those lapses with additional steps such as meetings with concerned departments in addition to our usual transfusion committee meetings. Blood utilization practices were then reaudited over 1 month with another smaller but more focused audit to look at specific aspects of blood usage. We studied all requests for RBCs over 1 month and analyzed their usage using five indices. This helped us to assess the efficacy of blood usage from point of request, through storage and handling at the blood bank up to the point of issue. We studied the usage of packed RBCs (PRBCs) overall for this 1 month and separately for both medical and surgical cases. Division of the cases as medical and surgical provided a unique way of evaluating the effect on blood utilization of well-defined guidelines and prediction of worst-case scenarios, respectively. We also subdivided both of these categories into super specialties to provide a more streamlined analysis of our results and conclusions.

Aims and objectives

Our aim was to study the role of regular audit and interdepartmental communication in improving blood utilization practices. We audited blood utilization over a period of 6 months using four indices (C/T ratio, TI, %T, and NUP), looking at institutional blood utilization as a whole.

We identified certain lapses that we addressed through measures such as additional interdepartmental meetings over and above our usual transfusion committee meetings. These interactions, in turn, helped us recognize the difference in policies and practices between departments.

Accordingly, our next audit was redesigned to obtain more specific information about improvements in blood utilization in different departments, after those corrective measures were undertaken. The reaudit used an additional newer index-WAPI and assessed all cases as an institutional whole and then separately as medical and surgical cases, subspecialty wise, for a more focused analysis.

  Materials and Methods Top

This is a retrospective study conducted at the blood bank of our hospital. An initial audit was done over a period of 6 months. All requests for PRBCs were analyzed for patient demographics, ward, indication for transfusion, and number of units requested. The number of units crossmatched and the number of units issued against each request were obtained from the blood bank records. These data were analyzed for four indices – C/T ratio, %T, TI, and NUP.

The reaudit after initiating appropriate measures was done over 1 month. The total study duration was 12 months (December 2017–November 2018). All requests for PRBCs for inpatients that were received and the crossmatch and issue register maintained by the department were used. All data as in the previous audit were collected from their respective sources and the four indices were calculated. We also documented the number of units that had been issued, but returned to the blood bank and had to be discarded instead of being issued to another patient (e.g., clot, hemolysis, or leakage in bag). We used another additional index in this audit-WAPI.

If multiple crossmatches were asked for the same patient during one episode of hospitalization, it was considered as one case. For our reaudit, all the collected data were evaluated as a whole and then divided into two categories – medical and surgical, based on both ward and indication. Each category was subdivided into four subcategories

  1. MEDICAL – General, intensive care unit/intensive treatment unit, pediatric, and others (super specialties, e.g., gastroenterology)
  2. SURGICAL – General (including orthopedics), obstetrics, pediatric surgery, and others (super specialties, e.g., cardiothoracic surgery).

The five indices that we compiled for monitoring blood usage after a thorough literature review were as follows:

  1. C/T ratio = (total number of units crossmatched)/(total number of units transfused); target value ≤2.5
  2. TI = (total number of units transfused)/(total number of patients crossmatched); target value ≥0.5
  3. %T = (total number of patients transfused) × 100/(total number of patients crossmatched); target value ≥30%[5]
  4. NUP = (total number of units requested but not used) × 100/(total number of units requested)
  5. WAPI = (total units discarded after issue) × 100/(total units issued); target values ≤2.5% for RBCs. ≤4% for platelets.

For the reaudit, the first three of these indices were calculated and compiled for the two broad categories and each of their four subcategories, NUP was calculated for the two broad categories and WAPI for the entire month as a whole. The data were compiled and analyzed on Microsoft Excel 2010.

  Results Top

For the first audit, a total of 4450 units were crossmatched for 2370 patients, but only 1216 units were transfused to 776 patients. The values for the four indices are provided in [Table 1].
Table 1: Values for blood utilization indices as per the first audit

Click here to view

For the reaudit, we decided to look at the data as a whole and as medical and surgical cases separately, first as the two broad specialties and then dividing each of them into major subspecialties. The total number of cases analyzed was 948. Of these, 501 (52%) were deemed to be medical and 447 (48%) were deemed to be surgical. The most common medical indication was anemia, whereas the most common surgical indication was preemptive request before a surgical procedure.

When C/T ratio, %T, and TI were evaluated overall and for these two broad categories, only C/T ratio for surgical cases was outside the target range (3.5). These values are tabulated in [Table 2].
Table 2: Values for blood utilization indices of medical and surgical cases as broad categories

Click here to view

When these indices were calculated subspecialty wise, all the medical subspecialties met the designated values for all the indices, indicating efficient blood usage [Table 3].
Table 3: Subspecialty-wise values of blood utilization indices for medical cases

Click here to view

As far as the surgical subspecialties are concerned, only the general (including orthopedics) subcategory had values of all three indices within the acceptable range, the super specialties had values of one of three indices beyond the acceptable range (TI), pediatric surgery had two of three indices beyond the acceptable range (C/T ratio and TI). The most unsatisfactory values of indices were seen in the obstetrics department; all three indices had values outside the acceptable range. These values are summarized in [Table 4].
Table 4: Subspecialty-wise values of blood utilization indices for surgical cases

Click here to view

WAPI was calculated as a single figure for the month and the value derived was 0.1% which is much less than the highest acceptable value of 2.5% for PRBCs.

The NUP was calculated overall and for the two broad specialties only. The overall NUP was 24%. When segregated, for medical specialties, it was 11% and for surgical specialties it was 37%.

All indices, when calculated for the overall data, showed a marked improvement in the reaudit as compared to the first.

To be able to justify the necessity of crossmatch policy in our institute, we also traced the wastage of PRBCs due to outdating. It was 0.27% (3 of 1109 PRBCs).

  Discussion Top

The role of transfusion services in ensuring appropriate blood usage is predominantly to monitor blood ordering and issue and help to formulate guidelines for better utilization of blood and blood products. More studies are required in this field, especially in the tertiary care setting, to evaluate blood usage patterns.

Regular monitoring is also necessary to ensure that blood utilization is appropriate. We, therefore, studied the importance of audits in our setting. Efforts were made to address the shortcomings in utilization practices that were revealed by a routine audit. We then performed another, smaller but more focused audit to assess the effectiveness of those steps. We were able to identify all the areas that had shown improvement and the ones that needed further revision and/or implementation of existing guidelines on blood utilization practices.

C/T ratio has been the chief index used to monitor blood and blood product utilization. However, use of other, newer indices help us look at various aspects of blood and blood products utilization, more comprehensively from storage to issue. We have compiled and used five such indices. Their relationship with the steps of blood handling, ordering, and issue is highlighted in [Figure 1]. As of now, the mechanism to trace blood utilization after issue is incomplete at our institution and is being worked upon.
Figure 1: Flowchart showing blood handling, ordering and issue, and the indices used to monitor each step

Click here to view

The lacunae in blood utilization practices identified by our first audit were addressed by interdepartmental meetings and staff trainings in addition to transfusion committee meetings. They helped us to gain insight into the different policies followed by different departments. While guidelines for medical indications for transfusions are well-defined, preemptive transfusions for surgical cases are mainly requested in anticipation of the worst-case scenario. We used this knowledge to design our reaudit to focus on specific departments.

In our reaudit, we monitored utilization practices overall, and separately for medical and surgical cases. A comparison between medical and surgical cases in the reaudit helped us to identify the effect of difference in policies on blood usage. Studying medical cases also helped reaffirm that availability and adherence to guidelines on transfusion helped to ensure efficient utilization in those cases.

The department-wise approach used in the reaudit not only revealed improvement in blood utilization practices in most departments, but also helped to identify the ones where blood utilization was suboptimal. We also recognized that in vulnerable age groups such as pediatric patients, it may not always be possible to choose efficient blood utilization over caution. We were also able to identify that requests received from this department are considerably low and does not significantly affect blood utilization indices as a whole.

Crossmatching blood and blood products means that those units are unavailable for any other patient for 24 h as per our institutional policy. Hence, unnecessary crossmatches have an adverse effect on turnaround time for issue and results in wastage of workforce. In surgical cases, blood ordering is mostly preemptive in consideration of the worst-case scenario.[1] Furthermore, certain institutional policies such as ordering PRBCs routinely before every lower segment cesarean section (LSCS) or ordering blood products in bulk for oncology patients may be responsible for inefficient blood usage in certain departments. Hence, striking a balance between these two aspects is a must for ensuring proper blood ordering and utilization. This requires a multidisciplinary approach. For example, after the reaudit revealed unsatisfactory C/T ratio, we organized discussions with the G&O department about limiting preemptive requests to high-risk LSCS cases only.

While a WAPI of 0.1% indicates satisfactory preparation and storage practices at the blood bank level, NUP as high as 37% indicates that >1/3rd of all PRBCs crossmatched for surgical indications are not even used. It is, therefore, evident that there is a scope for modifications of surgical blood ordering guidelines. In the reaudit, segregation of the cases into medical and surgical cases helped us appreciate the effect of the multiple and different factors influencing blood utilization indices for these two categories.

A similar study done by Yazdi et al., done at a university hospital in Iran,[6] focuses on surgical cases and divides them into type of surgery and then calculates utilization indices for each type. They found that the overall C/T ratio was 3.71, TI was 0.31, and %T was 16.83. The most inappropriate usage was seen in ENT and G&O surgeries. They also found that pretransfusion blood parameters (PT, Hb, and platelet count) did not correlate significantly with number of transfusions. Closer to home, a study in a hospital at Jammu, North India, by Yasmeen et al.,[5] looked at transfusion of each type of component based on the indications and department. They calculated TI, C/T ratio, and %T as overall and department-wise values. The overall values are −0.8, 1.12, and 88.8% respectively, indicating efficient usage. They also compared their values with several other studies. According to their cited references, C/T ratio across several studies done in India and abroad range between 1.12 and 5 or even as high as 41.6; TI was as low as 0.06, or as high as 1.18; %T was between 79% and 97.2%. These wide ranges highlight the possible impact of differences in hospital or even national policies on blood transfusions.

To ensure more efficient blood usage, many centers have begun to favor the type and screen (T&S) policy. It consists of an ABO-Rh grouping and a screen for unexpected antibodies. The risk of transfusing incompatible blood by this method is minuscule and has been shown to reduce unnecessary crossmatching and wastage of blood by outdating [2],[7] A recent study by Aggarwal et al.[8] at a tertiary care hospital-based blood bank in Northern India, compares the efficacy of blood usage before and after implementation of a T and S policy. They demonstrated the benefits of this policy with respect to considerable reduction in C/T ratio, issue TAT, outdating of RBC units, person-hour consumption, and increase in savings. In our institute, however, despite a crossmatch policy, wastage of PRBCs due to outdating during the period of study was a mere 0.27%.

Defining and using a MSBOS (maximum surgical blood ordering schedule)[9] or SBOE (surgical blood ordering equation) are also proven ways to make blood usage more efficient. In studies by Kajja et al.,[10] Mahadevan et al.,[11] and others [12],[13],[14],[15] these approaches have shown marked improvement in blood usage, with SBOE reportedly being more effective.[16]

One significant limitation of our study was that the indices we have used allow us to look at utilization practices up to point of issue. A means to trace utilization after issue has been implemented. The residents responsible for transfusion are required to fill in the transfusion report form for every unit of blood issued and the same should be returned to the blood bank within 24 h. This transfusion report form will have the details of what happened to the unit of blood issued by the blood bank for a given patient until the final disposal of the blood bag. The blood bank is closely monitoring to ensure that all the transfusion report forms are received by the blood bank which will help us to keep track on the effective utilization of blood that is issued.

  Conclusion Top

Based on our first audit as a part of this study, we were able to recognize deficiencies in blood usage practices and addressed them. A reaudit revealed a considerable improvement in blood utilization overall, presumably as a result of the measures undertaken. This highlighted the role of regular audits in identifying gaps in blood usage practices and evaluating the effectiveness of measures taken to improve the same.

While addressing the lapses in blood utilization, institutional policies that dictate blood usage which may contribute to inefficient usage should also be addressed. Interdepartmental meetings and transfusion committee meetings can be instrumental in this regard. Knowledge of specialty-specific blood utilization policies also help us, in turn, to come up with a more streamlined approach in further audits to evaluate the effects of those policies on blood utilization.

Editing blood-ordering practices, a gradual shift to T and S approach, regular review, and revision of the MSBOS are also to be considered to improve blood utilization. Regular audits are invaluable in monitoring the effectiveness of existing or new policies. Furthermore, whether it is a shift to T and S policy or better blood ordering practices, communication between departments and transfusion services is a key.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Bhutia SG, Srinivasan K, Ananthakrishnan N, Jayanthi S, Ravishankar M. Blood utilization in elective surgery – Requirements, ordering and transfusion practices. Natl Med J India 1997;10:164-8.  Back to cited text no. 1
Mead JH, Anthony CD, Sattler M. Hemotherapy in elective surgery: An incidence report, review of the literature, and alternatives for guideline appraisal. Am J Clin Pathol 1980;74:223-7.  Back to cited text no. 2
Charles KS, De Freitas L, Ramoutar R, Goolam R, Juman S, Murray D, et al. Blood utilisation in a developing society: What is the best index of efficiency? Transfus Med 2018;28:413-9.  Back to cited text no. 3
Hannon T. Waste not, want not. Am J Clin Pathol 2015;143:318-9.  Back to cited text no. 4
Yasmeen I, Ahmed A, Sidhu M. Pattern of blood component cross-matching and their utilization in a tertiary care hospital of Jammu hospital. Int J Res Med Sci 2018;6:1337-41.  Back to cited text no. 5
Yazdi AP, Alipour M, Jahanbakhsh SS, Gharavifard M, Gilani MT. A survey of blood request versus blood utilization at a university hospital in Iran. Arch Bone Jt Surg 2016;4:75-9.  Back to cited text no. 6
Novis DA, Renner S, Friedberg R, Walsh MK, Saladino AJ. Quality indicators of blood utilization: Three college of American pathologists Q-probes studies of 12,288,404 red blood cell units in 1639 hospitals. Arch Pathol Lab Med 2002;126:150-6.  Back to cited text no. 7
Aggarwal G, Tiwari AK, Arora D, Dara RC, Acharya DP, Bhardwaj G, et al. Advantages of type and screen policy: Perspective from a developing country! Asian J Transfus Sci 2018;12:42-5.  Back to cited text no. 8
Belayneh T, Messele G, Abdissa Z, Tegene B. Blood requisition and utilization practice in surgical patients at university of Gondar hospital, Northwest Ethiopia. J Blood Transfus 2013; 2013:758910.  Back to cited text no. 9
Kajja I, Bimenya GS, Eindhoven GB, ten Duis HJ, Sibinga CT. Surgical blood order equation in femoral fracture surgery. Transfus Med 2011;21:7-12.  Back to cited text no. 10
Mahadevan D, Challand C, Clarke A, Keenan J. Maximum surgical blood ordering schedules for revision lower limb arthroplasty. Arch Orthop Trauma Surg 2011;131:663-7.  Back to cited text no. 11
Hall TC, Pattenden C, Hollobone C, Pollard C, Dennison AR. Blood transfusion policies in elective general surgery: How to optimise cross-match-to-transfusion ratios. Transfus Med Hemother 2013;40:27-31.  Back to cited text no. 12
Fenelon C, Galbraith JG, Kearsley R, Motherway C, Condon F, Lenehan B. Saving blood and reducing costs: Updating blood transfusion practice in lower limb arthroplasty. Ir Med J 2018;111:730.  Back to cited text no. 13
Hardy NM, Bolen FH, Shatney CH. Maximum surgical blood order schedule reduces hospital costs. Am Surg 1987;53:223-5.  Back to cited text no. 14
Lowery TA, Clark JA. Successful implementation of maximum surgical blood order schedule. J Med Assoc Ga 1989;78:155-8.  Back to cited text no. 15
Sakurai Y, Okada C. Comparison by simulation of the efficiency of surgical blood order equation (SBOE) with that of maximum surgical blood order schedule (MSBOS). Masui 2001;50:69-75.  Back to cited text no. 16


  [Figure 1]

  [Table 1], [Table 2], [Table 3], [Table 4]


Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

  In this article
Materials and Me...
Article Figures
Article Tables

 Article Access Statistics
    PDF Downloaded56    
    Comments [Add]    

Recommend this journal