Problem Specification

Abdel Moniem Mukhtar, Dr.P.H., MPH, BDS, Research Methodology Module, AUW on Septmember 2012

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Research Question: PECOS and PICOS

P opulationI nterventionC omparisonO utcomeS tudy design

P opulationE xposureC omparisonO utcomeS tudy design

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Participants: STROBE

• “Give the eligibility criteria, and the sources and methods of selection of participants” [Von Elm, 2007, S. 1625]

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Population: PRISMA

• „Providing information about the population requires a precise definition of

• a group of participants (often patients), such as men over the age of 65 years,

• their defining characteristics of interest (often disease), and possibly

• the setting of care considered, such as an acute care hospital.“ [Liberati, 2009, S. 5]

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Setting: STROBE

• „ Describe the

• setting,

• locations, and relevant dates, including periods of recruitment,• • exposure,

• follow-up, and

• data collection.“ [Von Elm, 2007, S. 1625]

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Setting: STROBE

• „ Clearly define all

• outcomes,

• exposures,

• predictors,

• potential confounders, and effect modifiers.

• Give diagnostic criteria, if applicable.“ [Von Elm, 2007, S. 1625]

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Intervention: PRISMA

• „The interventions (exposures) under consideration in the systematic review need to be transparently reported. For example, if the reviewers answer a question regarding the association between a woman's prenatal exposure to folic acid and subsequent offspring's neural tube defects, reporting the

• dose, • frequency, and • duration of folic acid used in different studies

is likely to be important for readers to interpret the review's results and conclusions. Other interventions (exposures) might include diagnostic, preventative, or therapeutic treatments, arrangements of specific processes of care, lifestyle changes, psychosocial or educational interventions, or risk factors.“[Liberati, 2009, S. 5]

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Comparator: PRISMA

• „Clearly reporting the comparator (control) group intervention(s), such as• usual care,• drug, or • placebo,

is essential for readers to fully understand the selection criteria of primary studies included in systematic reviews, and might be a source of heterogeneity investigators have to deal with.

• Comparators are often very poorly described. Clearly reporting what the intervention is compared with is very important and may sometimes have implications for the inclusion of studies in a review.

• Many reviews compare with “standard care” which is otherwise undefined; this should be properly addressed by authors.” [Liberati, 2009, S. 5]

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Outcome: PRISMA

• „The outcomes of the intervention being assessed, such as • mortality, • morbidity, • symptoms, or • quality of life improvements,

should be clearly specified as they are required to interpret the validity and generalizability of the systematic review's results“ [Liberati, 2009, S. 5]

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• Mortality• Patient-relevant morbidities• Burden of disease, e.g. Hospitalization• Burden of Intervention• Quality of life• Patient-reported statisfaction, including desired autonomy [Bastian, 2006;

Schünemann, 2006].

• For most patient-relevant outcomes, with the exception of mortality, it is difficult to assess the relevance of the degree of severity.

Outcome: Patient‘s Relevance

What is a hard endpoint?

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• The patient‘s relevance of an outcome decrease as its association with the attributes of the following increases:

–the disease, e.g. changes in vital signs or pathophysiological values

–the physician, e.g. number of operations

–the system, e.g. volume of service.

• Such outcomes are called surrogate endpoints.

Outcome: Surrogate Endponits

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Outcome: Unvalidated Surrogate Endpoints

[Mühlhauser, 1996]

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Thank you for your kind attention

Dr. P.H. Abdel Moniem Mukhtar, MPH, BDS

Head of Research

Public Health Institute

Sahafa, P.O. Box 9099

Khartoum/ Sudan

Tel.:  +249-9-256 001 61

Email: mukhtar@phi.edu.sd

moniem.mukhtar@gmail.com

Website: www.phi.edu.sd