Condition category
Circulatory System
Date applied
09/03/2007
Date assigned
04/05/2007
Last edited
02/09/2009
Prospective/Retrospective
Retrospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

Contact information

Type

Scientific

Primary contact

Ms Cheryl Carling

ORCID ID

Contact details

PO box 7004
St Olavs Plass
Oslo
N-0130
Norway
+47 (0)98627327
cheryl.carling@kunnskapssenteret.no

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

N/A

Study information

Scientific title

Acronym

HIPPO 2 (Health Information Project, Presentation Online)

Study hypothesis

In terms of congruence between decisions and values:
1. "Relative risk reduction" is inferior to the “absolute” summary statistics
2. "Absolute risk reduction" is superior to other “absolute” summary statistics, and
3. There is no congruence between decisions and values for "event rates"

Ethics approval

Ethics approval received from the University at Buffalo (New York, USA), Health Sciences Institutional Review Board, approved on 15 May 2002.

Study design

Randomised controlled trial

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Trial setting

Not specified

Trial type

Other

Patient information sheet

Condition

Hypercholesterolaemia (hypothetical scenario)

Intervention

Presentations of summary statistic showing evidence of statins' effectiveness in preventing coronary heart disease over ten years.

The participants viewed one of the following six presentations:
1. Relative risk reduction (RRR)
2. Absolute risk reduction (ARR)
3. Numbers needed to treat (NNT)
4. Event rates (ER)
5. Tablets needed to take (TNT)
6. Whole numbers (WN)

Intervention type

Other

Phase

Not Specified

Drug names

Primary outcome measures

Hypothetical treatment decision to take or not to take statins.

Secondary outcome measures

Understanding of and satisfaction with information, and preferred summary statistic.

Overall trial start date

01/06/2003

Overall trial end date

31/07/2005

Reason abandoned

Eligibility

Participant inclusion criteria

1. At least 18 years of age
2. Fluent in English or Norwegian

Participant type

Patient

Age group

Adult

Gender

Both

Target number of participants

4,800

Participant exclusion criteria

Previous participation in this trial

Recruitment start date

01/06/2003

Recruitment end date

31/07/2005

Locations

Countries of recruitment

Canada, Norway, United States of America

Trial participating centre

PO box 7004
Oslo
N-0130
Norway

Sponsor information

Organisation

Norwegian Knowledge Centre for the Health Services (Norway)

Sponsor details

PO box 7004
St Olavs Plass
Oslo
N-0130
Norway
+47 (0)23 25 50 00
post@kunnskapssenteret.no

Sponsor type

Other

Website

http://www.kunnskapssenteret.no/

Funders

Funder type

Research council

Funder name

Norwegian Research Council (Norway)

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

1. 2008 results in http://www.ncbi.nlm.nih.gov/pubmed/19030110
2. 2009 results in http://www.ncbi.nlm.nih.gov/pubmed/19707575

Publication citations

  1. Results

    Carling C, Kristoffersen DT, Herrin J, Treweek S, Oxman AD, Schünemann H, Akl EA, Montori V, How should the impact of different presentations of treatment effects on patient choice be evaluated? A pilot randomized trial., PLoS ONE, 2008, 3, 11, e3693, doi: 10.1371/journal.pone.0003693.

  2. Results

    Carling CL, Kristoffersen DT, Montori VM, Herrin J, Schünemann HJ, Treweek S, Akl EA, Oxman AD, The effect of alternative summary statistics for communicating risk reduction on decisions about taking statins: a randomized trial., PLoS Med., 2009, 6, 8, e1000134, doi: 10.1371/journal.pmed.1000134.

Additional files

Editorial Notes