1 / 15

Randomisation ceremonies: from ping-pong to football matches

Randomisation ceremonies: from ping-pong to football matches. Richard Hayes. JAMA 1995; 273: 408-412. 2,838 citations . Aims of public randomisation ceremonies. To explain background to trial To explain need for random allocation and procedures to be used for this

luna
Télécharger la présentation

Randomisation ceremonies: from ping-pong to football matches

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Randomisation ceremonies: from ping-pong to football matches Richard Hayes

  2. JAMA 1995; 273: 408-412 2,838 citations

  3. Aims of public randomisation ceremonies • To explain background to trial • To explain need for random allocation and procedures to be used for this • To carry out randomisation using transparent procedure, involving key stakeholders Rationale is to ensure fairness, transparency, buy-in, engagement Stakeholders: Government representatives, community leaders, community representatives

  4. Ghana bednet trial • Rural area of Northern Ghana • Widely scattered households • Divided into 96 clusters of geographically contiguous households - average of 1400 persons per cluster • 48 clusters: impregnated bednets • 48 clusters: control arm – bednets at end of trial • Mortality in children (6-59m) reduced by 17% • Randomisation carried out by lottery in 10 paramount chiefdoms in study area Binka et al, TMIH 1996, 1: 147-154

  5. Ghana bednet trial

  6. MEMA kwaVijana trial • 20 rural communities in Mwanza Region, Tanzania • Adolescent sexual health intervention • In-school sexual health education • Youth-friendly services • Youth condom distributors • Cohort of 9,645 young people (Av age 15.5y) followed up for 36 months • Further cross-sectional survey carried out 5-6y later • Effects on knowledge, attitudes and some reported sexual behaviours • No impact on HIV, pregnancy, other STIs Ross et al, AIDS 2007, 21:1943 Doyle et al, PLoSMed 2010, 7:e1000287

  7. MEMA kwaVijana trial

  8. MkV randomisation scheme • 20 clusters divided into three strata based on initial survey of HIV prevalence • High-risk: 6 clusters • Medium-risk: 8 clusters • Low-risk: 6 clusters • Stratified randomisation Possible allocations = 6C4 x 8C3x 6C3 = 28,000

  9. MkV restricted randomisation • Restricted randomisation • Used to ensure adequate balance across study arms • Restriction criteria • Mean HIV prevalence similar • Mean chlamydia prevalence similar • Two communities near mines evenly distributed • Even distribution over four districts • 953 of the 28,000 allocations satisfied criteria Hayes et al, Contemporary Clinical Trials 2005, 26:430

  10. MkV randomisation ceremony • Held with senior stakeholders • List of allocations presented, numbered 001–953 • Stakeholders asked to draw ping-pong balls numbered 0-9 from bucket • Number 039 selected: divides 20 communities into two sets of 10 • Final draw of ping-pong ball used to decide which set of 10 receives intervention

  11. Zamstar trial • Impact of 2 intensive TB control strategies evaluated in 2x2 factorial CRT • Arm 1: Enhanced case finding • Arm 2: Household intervention • Arm 3: ECF + household • Arm 4: Neither intervention • 24 communities in Zambia and S Africa • Household intervention decreased TB prevalence by 20% and reduced transmission to children • No effect of ECF Ayles et al, Trials 2008, 9:63

  12. Zamstar randomisation scheme • 24 clusters divided into 4 strata based on initial TST survey in schoolchildren • Zambia/High TST: 8 clusters • Zambia/Low TST: 8 clusters • S Africa/High TST: 4 clusters • S Africa/Low TST: 4 clusters • Stratified randomisation Possible allocations = = 3,657,830,400

  13. Zamstar restricted randomisation • Restriction criteria • Similar number with high estimated HIV prevalence in each arm • Similar mean TST prevalence • Similar number of “open” communities • Similar number of urban communities • Political constraints • Randomly selected allocations until 1,000 which satisfied restriction criteria Sismanidis et al, Clin Trials 2008, 5:316

  14. Zamstar randomisation ceremony • Held on football pitch during tournament in Zambia • List of acceptable allocations numbered 000-999 • 24 volunteers representing clusters • Senior officials asked to draw footballs numbered 0-9 from sack • Number 773 selected: volunteers divided into four groups labelled A-D • More footballs drawn to determine study arm allocated to each group

  15. Special thanks to • Fred Binka for the Ghana video • BabisSismanidis for the Zamstar video • The PIs and investigators of the Ghana bednet, MkV and Zamstar trials

More Related