PHA-Exchange> Serious faults identified in design and reporting of abstinence-only studies OXFORD UNIVERSITY

[Marcy Bloom]

 NEWS: Serious faults identified in design and reporting of abstinence-only
studies OXFORD UNIVERSITY

http://www.aidsmap.com/en/news/919D99F3-ED3E-42BB-AB4B-48D708B81702.asp?
type=preview
 
Serious faults identified in design and reporting of abstinence-only studies
 
Michael Carter, Friday, January 12, 2007
  

Studies exploring the effectiveness of "abstinence only" programmes to
prevent HIV are limited by severe methodological weaknesses, investigators
from Oxford University assert in the January 11th edition of AIDS. 

The investigators found that abstinence studies did not include enough
participants to justify the initiation of large-scale public health
initiatives; did not specify procedures used for randomisation; did not
report clinically meaningful outcomes (such as incident HIV infections); did
not use intent-to-treat analyses; did not provide enough details to
demonstrate if interventions were delivered as planned; and did not compare
the effectiveness of abstinence programmes with health education initiatives
that provided wider information on sexual health, including condom use. 

Abstinence-only HIV prevention programmes have been the source of fierce
debate in recent years. Often acrimonious discussions have focused on the
public health, political and moral aspects of these programmes. 

Despite these heated debates, investigators at the Centre for Evidence-Based
Medicine at Oxford University were concerned that evidence from clinical
trials regarding the effectiveness or otherwise of abstinence programmes
were being overlooked. They expressed particular concern that a forthcoming
Cochrane review of the clinical effectiveness of abstinence-only education
in richer countries, which identified policy and practice implications, is
in fact, limited by reporting shortcomings from the trials that informed it.


The Oxford scientists found "recurring reporting deficiencies that may limit
the extent to which programme trials can make specific recommendations for
policy and practice. 

Despite the use of randomised controlled trial designs, no abstinence study
met the CONSORT reporting standards and missing data was an obstacle to
meta-analysis. 

Deficiencies in trial design and reporting in five broad areas were
highlighted by the Oxford investigators: 


Randomisation - no study properly described its randomisation procedure.
The authors emphasise that such are "critical for appraising trials".
The investigators add "despite searching 30 databases, 16,765 abstracts and
unpublished literature, the review encompasses only 13,191 participants from
randomised controlled trials (a small figure for a widespread public health
intervention)."



Outcome measures: Abstinence studies avoided reporting "clinically
meaningful outcomes" of behavioural change such as HIV incidence.
Rather, they focused on self-reported sexually transmitted infections.
In addition, it was often unclear whether oral or anal sex were measured,
and terms such as "virginity" and "intercourse" were often poorly defined. 



Conducting appropriate analyses: No study conducted an intent-to-treat
analysis to counter reporting bias by accounting for dropouts.



Could not determine if programmes were delivered as planned: Incomplete
reporting made it difficult for the investigators to tell exactly what
programme activities, settings, facilities and contexts were used.



No comparison data: Only one study compared abstinence programmes with more
comprehensive sexual health education.


The authors conclude, "abstinence-only programme evaluations...must report
key data more completely." 

Reference 

Underhill K et al. Reporting deficiencies in trials of abstinence-only
programmes for HIV prevention. AIDS 21: 266 - 267, 2007.