Extraction form for project: The prognostic value of a baseline platelet count in patients treated with percutaneous coronary intervention: a systematic review and dose-response meta-analysis

Design Details

1. What is the source of data (eg, cohort, RCT, registry data)?
Domain - Source of data. Please, provide the study design
2. What was the recruitment method?
Domain - Participants. Please, provide how study population was gathered.
3. The country of recruitment
Domain - Participants. Please, provide the country (countries) of the study.
4. number of centres number of centres
Domain - Participants
5. Settings for study participants
Domain - Participants
6. Inclusion criteria
Domain - Participants. Please, specify additional inclusion criteria
7. Exclusion criteria
Domain - Participants
8. Details of treatments received (if relevant)
Domain - Participant. Please, specify additional details. Choose all relevant options
9. Study dates
Domain - Participants

Arms

Arm NameArm Description
Baseline platelet valuesThe study provided data on prognostic value of baseline platelet count.

Arm Details

1. Definition and method for measurement of prognostic factors
Domain - Prognostic factors. Please, provide definitions of thrombocytopenia or thrombocytosis if relevant
Baseline platelet values
Definitions
Blood analyzer used
2. Timing of PLT measurement (eg, at patient presentation, diagnosis, treatment initiation, at the end of PCI)
Domain - Prognostic factor.
Baseline platelet values
3. Were prognostic factors assessed blinded for outcome, and for each other (if relevant)?
Domain - Prognostic Factor.
Baseline platelet values
4. Handling of prognostic factors in the analysis (eg, continuous, linear, non-linear transformations or categorised)
Domain - Prognostic factor
Baseline platelet values

Sample Characteristics

1. Was a sample size calculation conducted?
Domain - Sample size. Sample size calculation might be provided in the protocol published previously.
Baseline platelet values
2. What is the number of included participants?
Domain - Sample size
Baseline platelet values
3. What is the number of patients experienced outcomes?
Domain - Sample size. If several endpoints are reported, please, provide the number of primary endpoints
Baseline platelet values
MACE
4. Number of outcomes or events in relation to the number of candidate prognostic factors (events per variable)
Domain - Sample size. For the primary endpoint
Baseline platelet values
5. Number of participants with any missing value (in the prognostic factors and outcomes)
Domain - Missing data. Please, provide data on the number of participants with any missing value in the the prognostic factors?
Baseline platelet values
6. Details of attrition (loss to follow-up) and, for time-to-event outcomes, number of censored observations (ideally in each category for those categorical prognostic factors of interest)
Domain - Missing data.
Baseline platelet values
7. Handling of missing data (eg, complete case analysis, imputation, or other methods)
Domain - Missing Data
Baseline platelet values
8. Modelling method (eg, linear, logistic, Cox, parametric survival, competing risks) regression)
Domain - Analysis.
Baseline platelet values
9. How modelling assumptions were checked; in particular, for time-to-event outcomes and the analysis of hazard ratios, the method for assessing non-proportional hazards (non-constant hazard ratios over time)
Domain - Analysis.
Baseline platelet values
10. Method for selection of prognostic factors for inclusion in multivariable modelling
Domain - Analysis.
Baseline platelet values
11. Method for selection or exclusion of prognostic factors during multivariable modelling, and criteria used for any selection or exclusion
Domain - Analysis
Baseline platelet values
Method for selection or exclusion
criteria used for any selection
12. Method of handling each continuous prognostic factor
Domain - Analysis.
Baseline platelet values
Cutpoints
Units for linear variable
13. Number and set of adjustment factors
Domain - Results
Baseline platelet values
Number
Set
14. Interpretation of presented results
Domain - Interpretation
Baseline platelet values
15. Comparison with other studies, discussion of generalisability, strengths and limitations
Domain - Interpretation
Baseline platelet values

Outcomes

TypeDomainSpecific measurement (i.e., tool/definition/specific outcome)PopulationsTimepoints
CategoricalBaseline platelet valuesAll-cause mortality
  • All Participants
  • long-term follow-up

Outcome Details

1. Definition and method for measurement of outcomes
Domain - Outcomes. Please, specify the used definitions (international or self-defined) and method for measurement
Baseline platelet values
Definition
Method for measurement
2. Was the same outcome definition (and method for measurement) used in all participants?
Domain - Outcomes
Baseline platelet values
3. Types of outcomes (eg, single or combined endpoints)?
Domain - Outcomes.
Baseline platelet values
4. Were the outcomes assessed without knowledge of the candidate prognostic factors (that is, blinded)?
Domain - Outcomes.
Baseline platelet values
5. Were candidate prognostic factors part of the outcome (eg, when using a panel or consensus outcome measurement)?
Domain - Outcomes.
Baseline platelet values
6. Time of outcome occurrence or summary of duration of follow-up
Domain - Outcomes
Baseline platelet values

Risk of Bias Assessment

1. 1. Study Participation
Hayden JA, van der Windt DA, Cartwright JL, Côté P, Bombardier C. Assessing bias in studies of prognostic factors. Ann Intern Med. 2013 Feb 19;158(4):280-6.
The source population or population of interest is adequately described for key characteristics (LIST).
The sampling frame and recruitment are adequately described, including methods to identify the sample sufficient to limit potential bias (number and type used, e.g., referral patterns in health care)
Period of recruitment is adequately described
Place of recruitment (setting and geographic location) are adequately described
Inclusion and exclusion criteria are adequately described (e.g., including explicit diagnostic criteria or “zero time” description).
There is adequate participation in the study by eligible individuals
The baseline study sample (i.e., individuals entering the study) is adequately described for key characteristics
Summary Study participation
2. 2. Study Attrition
Hayden JA, van der Windt DA, Cartwright JL, Côté P, Bombardier C. Assessing bias in studies of prognostic factors. Ann Intern Med. 2013 Feb 19;158(4):280-6.
Response rate (i.e., proportion of study sample completing the study and providing outcome data) is adequate.
Attempts to collect information on participants who dropped out of the study are described.
Reasons for loss to follow-up are provided.
Participants lost to follow-up are adequately described for key characteristics.
There are no important differences between key characteristics (LIST) and outcomes in participants who completed the study and those who did not.
Study Attrition Summary
3. 3. Prognostic Factor Measurement
Hayden JA, van der Windt DA, Cartwright JL, Côté P, Bombardier C. Assessing bias in studies of prognostic factors. Ann Intern Med. 2013 Feb 19;158(4):280-6.
A clear definition or description of 'PF' is provided
A clear definition or description of 'PF' is provided
Method of PF measurement is adequately valid and reliable to limit misclassification bias
Appropriate cut-points are used.
measurement of PF is the same for all study participants
Adequate proportion of the study sample has complete data
Appropriate methods of imputation
Summary
4. 4. Outcome Measurement
Hayden JA, van der Windt DA, Cartwright JL, Côté P, Bombardier C. Assessing bias in studies of prognostic factors. Ann Intern Med. 2013 Feb 19;158(4):280-6.
A clear definition of outcome is provided
The method of outcome measurement used is adequately valid and reliable to limit misclassification bias
outcome measurement is the same for all study participants.
Summary
5. 5. Study Confounding
Hayden JA, van der Windt DA, Cartwright JL, Côté P, Bombardier C. Assessing bias in studies of prognostic factors. Ann Intern Med. 2013 Feb 19;158(4):280-6.
All important confounders are measured.
Clear definitions of the important confounders measured are provided
Valid and Reliable Measurement of Confounders
confounding measurement are the same for all study participants.
Appropriate methods are used for imputation
Important potential confounders are accounted for in the study design
Important potential confounders are accounted for in the analysis
Summary
6. 6. Statistical Analysis and Reporting
Hayden JA, van der Windt DA, Cartwright JL, Côté P, Bombardier C. Assessing bias in studies of prognostic factors. Ann Intern Med. 2013 Feb 19;158(4):280-6.
There is sufficient presentation of data to assess the adequacy of the analysis.
The strategy for model building is appropriate
The selected statistical model is adequate
There is no selective reporting of results.
Summary

Results

Categorical

Baseline platelet values (All-cause mortality)

All Participants
Descriptive StatisticsBetween Arm Comparisons
Baseline platelet values
long-term follow-up
Total (N analyzed)
Odds Ratio (OR)
Events
95% CI low (OR)
Percentage
95% CI high (OR)
p value
Within Arm ComparisonsNet Comparisons
Baseline platelet values