SUPERVISION OF SPUTUM SMEAR LABORATORIES

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SUPERVISION OF SPUTUM SMEAR LABORATORIES

• AIM OF SUPERVISION
• GENERAL ORGANIZATION
• INDICATORS FROM THE REGISTERS
• PROBLEM ORIENTED SUPERVISION

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AIM OF SUPERVISION

• Problem solving
• problems often there, not reported
• suspicion from quality assessment
• Continued education
• Motivation
• needs positive attitude
• avoid false accusations wrong emphasis on
  targets
• help whenever possible

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GENERAL ORGANIZATION

• Who??
• central lab supervisors too infrequently
• NTP supervisors (district, region) more
  efficient
• When??
• ideally at each visit to a centre
• at least
• always enquire about problems
• take sample for quality control, give feed-back

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GENERAL ORGANIZATION (2)

• How??
• needs good insight in AFB-microscopy
• and practice confirm positives as an exercise
• problem-oriented for highest efficiency
• quality assessment system part of supervision

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INDICATORS OF LAB PERFORMANCE

• From registers or reports
• Have been used for internal monitoring
• comparing smear- and culture-positivity
• Derive from numbers for smears only?

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TENTATIVE AFB-SMEAR INDICATORS

• Positivity rate among suspect smears
• Positivity rate among follow-up smears
• Low positive case smears
• Consistency within case series
• Case yield of first smear
• Number of smears per (positive) case
• Percent positive cases registered for treatment

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POSITIVITY SUSPECT SMEARS

• Indicates lab quality, but also
• accessibility (financial, geographical)
• selection of suspects
• Normal rate often not 10
• variations between NTPs accessibility, other
  diseases (HIV !)
• variations level of service, i.e. 3rd line
• seasonal variations ...
• Extract lab quality ??
• compare units at same level
• gross lab deficiencies may show

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POSITIVITY FOLLOW-UP SMEARS

• Sensitive indicator of lab quality ?
• Normal rate may be around 10
• population early treatment? MDR-TB? HIV?
• guidelines no. of smears first 2-3 months?
• correct registration targets!!
• Interpretation of too low rates
• superficial reading or bad microscope
• and/or poor staining

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LOW POSITIVE CASE SMEARS

• Less than 1 AFB per field/ all with AFB
• Normal rate 25-50 ?
• population accessibility, HIV
• requires /- correct quantification
• Interpretation
• too low superficial reading or bad microscope
• too high poor stain or staining
• confirmed by their absence among follow-up smears

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CONSISTENCY CASE SERIES

• of cases with AFB in all 2 or 3 smears
• Normal rate around 80 ?
• population accessibility, HIV
• sampling strategy (spot more variable)
• Interpretation
• 100 copying results?
• low problems with reading, microscope, staining
  or specimen collection
• isolated positives not rare serious problem
  doesnt know AFB or unusable microscope
  mislabeling

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CASE YIELD FIRST SMEAR

• cases with AFB in first smear
• Similar to consistency
• At least 85 ?
• population accessibility, HIV
• sampling strategy (no. of specimens, no. of
  spot)
• Interpretation as before
• 100 copying results?
• low reading, microscope, staining smearing
• more indicative of good specimen

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NO. OF (POSITIVE) SMEARS PER CASE

• Compares cases registered / smears done
• Respect of strategy and guidelines?
• at least X negatives per SM-
• at least 2 positives per SM
• Interpretation
• proper use of lab guidelines
• SM- gross deviations compare diagnostic units

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PERCENT POSITIVE CASES REGISTERED FOR TREATMENT

• Counts from lab versus treatment register
• easier than cross-checking registers
• Indicates
• patient-friendliness at all levels, including
  appropriate detection strategy
• lab transmission of results, delay
• (completeness of registration)
• Normal level
• can be gt99
• exception well-known TB referral centres

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HOW TO USE THESE INDICATORS?

• Internal monitoring, charting
• problem fluctuations
• --gt only larger units selected indicators ?

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HOW TO USE THESE INDICATORS?

• During supervision visits
• can be used by non-professionals
• one value, i.e. full quarter or year
• problem time constraint in big units
• selected indicators only, i.e. low positives
• scan rather than count
• Calculate from lab reports
• ideal analysis by computer
• problem few NTPs have lab reports!

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PROBLEM ORIENTED SUPERVISION

• Overall impression of the laboratory
• installations, equipment, personnel adequate ?
• supplies sufficient ? storage conditions ?
• safety waste disposal ?
• important cleanliness, tidiness

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PROBLEM ORIENTED SUPERVISION (2)

• Check the lab register for
• completeness ? up to date?
• plausibility of results
• i.e. isolated positives proportion scanty
  results
• workload lt25 smears daily?
• indicators of performance

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PROBLEM ORIENTED SUPERVISION (3)

• Look at smears macroscopically
• properly identified ?
• thickness of unstained smears ?
• colour of stained smears ?
• Check recent positives / ( neg.) microscopically
• image bright, clear and stable ?
• AFB visible ?
• strong red colour AFB, not background?

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PROBLEM ORIENTED SUPERVISION (4)

• Check cross-checking
• correct sampling possible ?
• all slides kept ?
• no result on slides ?
• sampling regularly done ?
• feed-back on results received ?
• errors ?
• type FN ? FP ?
• evolution
• need to call a specialist ?