Finding the best questions for measuring AIDS mortality using verbal autopsy:

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Finding the best questions for measuring AIDS
mortality using verbal autopsy

• A validation study in
• Kisesa, Tanzania
• and
• Manicaland, Zimbabwe

Ben Lopman
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Co-authors

• Manicaland Cohort
• Jennifer Smith
• Godwin Chawira
• Simon Gregson
• Kisesa Cohort
• Adrian Cook
• Yusufu Kumogola
• Milalu Ndege
• Basia Zaba
• Mark Urassa
• Raphael Isingo
• WHO
• Ties Boerma

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Objective

• To develop a classification system of AIDS/
  non-AIDS deaths using VA data validated against
  HIV testing that performs consistent in
• Place
• Time

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VA for AIDS mortality

• HIV/AIDS is the leading cause of death among
  young adults
• Hospital records and vital registration of deaths
  are inadequate for AIDS
• bias, underreporting and stigma.
• Improving measurement of AIDS mortality is urgent
  
• Monitoring the success of programmes relies on
  accurate measurement of AIDS deaths

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KisesaWard (Magu DSS) HIV Prev 1994/1995
6.0 2000/2001 8.3
Manicaland HIV/STD Prevention Study HIV
Prev 1998/2000 23.0 2001/2003 20.5
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Mortality surveillance and VA tool

• The study teams identified deaths through the use
  of checklists of all individuals interviewed at
  baseline
• Nurse conducted interview with primary caregiver
• VA developed in Kisesa, used in that site until
  2002. After which, a verbal autopsy questionnaire
  based on the INDEPTH standard was used
• This questionnaire lacked a number of questions
  related to opportunistic infections often seen in
  AIDS patients
• A nearly identical version was used in Manicaland
  in both Round 1 and Round 2.

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Gold Standard

• Gold standard of AIDS deaths. An individual who
  was
• a) HIV positive at previous test
• b) not accident/injury
• c) not direct obstetric deaths

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Training and testing datasets
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AIDS deaths (gold standard)
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Rule-based algorithm

• On TRAIN data
• Calculate LR for all signs symptoms
• Based on SPECIFICITY

1. Weight loss

2.
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(No Transcript)
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Specificity 15 to 44 year
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Sensitivity 15 44 year
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15 to 44 years (9 Signs/Symptoms)
Specificity
Sensitivity
Manicaland
Kisesa
Manicaland
Kisesa
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45 to 59 years (9 Signs/Symptoms)
Specificity
Sensitivity
Kisesa
Manicaland
Kisesa
Manicaland
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15 to 44 years, INDEPTH variables (5
Signs/Symptoms)
Specificity
Sensitivity
Manicaland
Kisesa
Manicaland
Kisesa
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Using INDEPTH questionsKisesa 1994-2002
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Using INDEPTH questionsManicaland R2
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AIDS CSMF, Correcting for misclassification
Estimate True
Manica R1 76 74
Manica R2 88 76
Kisesa 51 53
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Estimating HIV prevalence
Estimate (95 CI) True
Manica R1 24 (18-31) 23
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Conclusions

• Developed a set of criteria using VA that
  consistently measures AIDS mortality
• Algorithm performs consistently in these settings
  of variable HIV prevalence
• Only reliable for adults under age 45
• OK in Manicaland, fewer female AIDS deaths in
  older adults in Kisesa
• Not subject to clinical biases
• Can estimate HIV mortality in populations lacking
  serosurveillance

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INDEPTH and WHO VA

• Either of these widely used VA tools would face
  some limitations surveying AIDS mortality with
  the proposed criteria
• Highly predictive and common
• Herpes zoster, oral candidiasis, abscesses/sores
• Highly predictive and rare
• Vaginal tumors

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Acknowledgements

• Funding
• Health Metrics Network
• Wellcome Trust
• Netherlands Government
• People of Kisesa Ward, Tanzania and Manicaland
  Province, Zimbabwe
• Especially Kin and Caregivers