Module 10: Understanding Laboratory Data

*Image courtesy of: World Lung Foundation

• Describe how to monitor lab services

- Proper reporting and recording

• How to analyze data for

- quality

- effectiveness

Learning Objectives

Monitoring Laboratory Services

How do I work in the laboratory?

1. Communication between the laboratory and the clinic is the most important issue to look at

2. You can also collect some basic indicators on overall lab performance

What you probably can’t do

1. You won’t be able to assess the quality of smears / microscopy

2. Lab experts need to advise on safety protocols and correct use of equipment

These are the tools at your disposal

Talk Observe Analyse

Attitudes Actions Consistency

Understanding Processes Accuracy

Morale Conditions Effectiveness

Measure key indicators related to quality of diagnosis Accurate Verifiable Timely

Identify problems in implementing TB control activities (e.g., laboratory reporting delays)

Improve lab / program linkages and accountability Influence laboratory practice

Benefit for BNTP

Sputum Dispatch Register Facility TB Register Lab Register

Cross-Checking for Quality

Key Elements for Quality

• Quality begins with DATA– Proper registration of

• Suspects• Specimens• Results

– Three Key Tools • Suspect and Sputum Dispatch Register (SSD)• Laboratory Register• TB Facility Register (for confirmed cases)

Lab Procedure for TB Microscopy

1. Patient details recorded (specimen container and request form)

2. Forms and container assigned lab

reference number

3. Details entered in Laboratory Register.

4. Specimen quality checked and

recorded

5. Smear prepared.

6. Specimen stained, examined

7. Results reported back to facility.

Proper Registration is a 6-Part Process

SSDRegister

1. Suspects are registered

2. Specimens sent to Lab

LabRegister

3. Suspects are confirmed as cases or not

4. Results sent back to clinic

SSDRegister

5. Lab results are recorded in SSD for each suspect TB

Register

6. Confirmed CASES are registered in Facility TB Register

Register Cross-checks

• What is cross-checking?

• Why is it important?

• Who should do it?

• How is it done? 

What are Cross-checks?

Cross-checking is a simple task used to reveal many basic workflow and communications problems between the program and the laboratory.

It should be done regularly, and in conjunction with laboratory staff.

Cross-checking involves theSSD Register/ TB Register and the Lab Register

SSDRegister

LabRegister

FacilityRegister

Pt One Specimen

Pt Two Specimen

Pt Two Specimen

Pt Two Specimen

Pt Three Specimen

1.Check the lab register to see that all suspects from the SSD and their respective specimens are recorded.

SSDRegister

LabRegister

1. Patient One

2. Patient Two

3. Patient Three

1. Sputum Smear Positive

2. Sputum Smear Negative

2. Sputum Smear Negative

2. Sputum Smear Negative

3. Sputum Smear Positive

2. Check the SSD to be sure there are recorded results for every suspect

SSDRegister

LabRegister

Pt 1. Sputum Smear Positive

Pt 2. Sputum Smear Negative

Pt 3. Sputum Smear Positive

3. Next compare the SSD with the TB Register.Be sure that each confirmed smear-positive case is

registered and has their smear-results recorded in the Facility Register.

TBRegister

SSDRegister

1. Sputum Smear Positive

Pt 2. Ruled out- Not Registered

3. Sputum Smear Positive

1. Sputum Smear Positive

2. Sputum Smear Negative

3. Sputum Smear Positive

Sputum Smear Positive

Sputum Smear Positive

If you find a case in the Lab register which is NOT in the SSD register, then a case has been missed.

SSDRegister

LabRegister

Sputum Smear Positive

Negative

Negative

Sputum Smear Positive

Sputum Smear Positive??

Sputum Smear Positive

Sputum Smear Positive

Similarly, if you find a sputum smear-positive case in the Lab register and SSD which is NOT in the Facility Register,

then a case has been missed.

TBRegister

LabRegister

Sputum Smear Positive

Negative

Negative

Sputum Smear Positive

Sputum Smear Positive??

In these situations the case needs to be entered and treatment commenced ASAP.

Pt. 1 Sputum SS+

SSDRegister

LabRegister

Patient 1

Patient 2

Patient 2

Patient 3

Patient 3

??

Conversely, if there are no data for a Suspect in the Lab Register, this means the specimens were not received or

processed. Time to investigate!!

??

In these situations, new specimens need to be submitted and inquiries made regarding specimen

transport and receiving procedures.

Exercises

Divide into pairs. Using the handout conduct a lab and patient register cross-check

DISCUSSION What problems did you find? What are the underlying issues? How would you deal with them?

Communicating about Lab Issues

The Laboratory Manager The District Coordinator

The Lab and the District Coordinator

Talking to the laboratory manager can be interesting.

Listen carefully and identify issues for follow-up.

A good tip: Make sure that you speak with the Lab Manager and Clinic Matrons separately, at least once per M&E Visit – even if it is just an informal conversation.

Key Questions to Report on

Are there recording and reporting issues?

Are TB patients being lost?Are AFB results received from the lab within 24 hours of specimen

collection?Are all TB smear and culture results

reported by laboratories?Is the lab receiving a good quality

specimen that is well labeled?

What are we trying to achieve?

Through communication we can:Test level of knowledge

Gauge attitude and morale

Seek guidance on priority areas

Exercise - 20 mins

1. Divide into pairs. Using the handout as a guide, act out a typical discussion between a District TB Coordinator and a Lab Manager. The person doing the monitoring should take notes. After a 5 minute discussion, discuss findings.

2. Now start again, this time with your NTP Supervisor. Again, discuss your findings.

Analyzing Quality of Diagnosis - Advanced

Positivity rate amongst TB suspects Positivity rate amongst follow-up examinations Proportion of low-positive suspects Consistency within series of smears from TB suspects

Evaluating a Laboratory Register

ACKNOWLEDGEMENT:

Mycobacterium Reference Laboratory

Infectious Diseases Laboratories

South Australia

Introduction

The Laboratory Register provides a wealth of information – should be reviewed regularly– is an internal Quality Control activity– findings are directly relevant to program

management

Provides a simple, easy & rapid method of summarising the work conducted in a laboratory

Positivity Rate Among TB Suspects

Calculated by counting all examinations for TB suspects according to their results– numerator: total up all smear positive results– denominator: total up all positives plus negatives

– Expressed as a %

Positive (and Scanty)

Negatives and Positive (and Scanty )

Positivity Rate Among TB Suspects

Interpretation– varies considerably between countries– Expect 5-20% where TB is prevalent

>20% positivity rate• delayed patient presentation• delayed diagnosis

<5% positivity rate• over selection of TB suspects• large numbers of false-negative laboratory results

Positivity Rate Among Follow-up Patients

Calculated by counting all examinations for follow-up cases according to their results– numerator: total up all smear-positive results– denominator: total up all positives plus negatives

– Expressed as a %

Scanty and Positive

Negatives and Scanty and Positive

Positivity Rate Among Follow-up Patients

Expected Value: ~10%– Result dependent upon timing of follow-up sputums; if

more at 2 months, then higher, but lower if collected late in treatment

A total absence of smear-positives for follow-up is impossible

<5% • poor staining or poor microscopy

• poor quality specimens

• misconduct

Proportion of “low positives” among AFB-positive TB suspects

Calculated by determining the proportion of smear positive specimens with a Scanty or 1+ result

– numerator: total up all scanty + and 1+ results– denominator: total up all positives plus

– Expressed as a %

Scanty and 1+

Scanty and all Positive

Proportion of “low positives” among AFB-positive TB suspects

Expected Value ~ 40% Lower result:

– good quality staining but poor microscopy

(detection requires time and high quality work)

Higher result– poor quality staining (fewer 3+)– poor quality microscope– contamination of CF with environmental

mycobacteria

Concluding Comments

Evaluating a Laboratory Register in this way is a very useful tool contributing to Internal Quality Control of the laboratory

May be done monthly or quarterly May be graphed to display long term trends

in performance