Supplemental Digital Content 1: STROBE Statement—checklist of items that should be included in reports of observational studies.
Item
No. Recommendation
Page No.
Relevant text from manuscript Title and abstract 1 (a) Indicate the study’s design with a commonly used term in the title or
the abstract 2 abstract
(b) Provide in the abstract an informative and balanced summary of
what was done and what was found 2 abstract
Introduction
Background/rationale 2 Explain the scientific background and rationale for the investigation being reported
3 introduction
Objectives 3 State specific objectives, including any prespecified hypotheses 3-4 introduction Methods
Study design 4 Present key elements of study design early in the paper 4 Study Design
Setting 5 Describe the setting, locations, and relevant dates, including periods of recruitment, exposure, follow-up, and data collection
4 Study Design and
Research Subjects Participants 6 (a) Cohort study—Give the eligibility criteria, and the sources and
methods of selection of participants. Describe methods of follow-up Case-control study—Give the eligibility criteria, and the sources and methods of case ascertainment and control selection. Give the rationale for the choice of cases and controls
Cross-sectional study—Give the eligibility criteria, and the sources and methods of selection of participants
4 Study Design and
Research Subjects
(b) Cohort study—For matched studies, give matching criteria and number of exposed and unexposed
Case-control study—For matched studies, give matching criteria and the number of controls per case
Variables 7 Clearly define all outcomes, exposures, predictors, potential confounders, and effect modifiers. Give diagnostic criteria, if applicable
5 Data collection and Diagnostic criteria
Data sources/
measurement 8* For each variable of interest, give sources of data and details of methods of assessment (measurement). Describe comparability of assessment methods if there is more than one group
5 Data collection
Bias 9 Describe any efforts to address potential sources of bias NA
Study size 10 Explain how the study size was arrived at NA
Quantitative variables 11 Explain how quantitative variables were handled in the analyses. If applicable, describe which groupings were chosen and why
5 Statistical Analyses Statistical methods 12 (a) Describe all statistical methods, including those used to control for
confounding
5-6 Statistical Analyses (b) Describe any methods used to examine subgroups and interactions 6 Statistical Analyses
(c) Explain how missing data were addressed 5 Data Processing
(d) Cohort study—If applicable, explain how loss to follow-up was addressed Case-control study—If applicable, explain how matching of cases and controls was addressed
Cross-sectional study—If applicable, describe analytical methods taking account of sampling strategy
NA
(e) Describe any sensitivity analyses 6 Statistical Analyses
Results
Participants 13* (a) Report numbers of individuals at each stage of study—eg numbers potentially eligible, examined for eligibility, confirmed eligible, included in the study, completing follow-up, and analysed
6 RESULTS
(b) Give reasons for non-participation at each stage 6 RESULTS
(c) Consider use of a flow diagram Figure 1
Descriptive data 14* (a) Give characteristics of study participants (eg demographic, clinical, social) and information on exposures and potential confounders
Table 1 (b) Indicate number of participants with missing data for each variable of
interest
NA (c) Cohort study—Summarise follow-up time (eg, average and total amount) NA Outcome data 15* Cohort study—Report numbers of outcome events or summary measures over
time
6-7 RESULTS
Case-control study—Report numbers in each exposure category, or summary measures of exposure
Cross-sectional study—Report numbers of outcome events or summary measures
Main results 16 (a) Give unadjusted estimates and, if applicable, confounder-adjusted estimates and their precision (eg, 95% confidence interval). Make clear which confounders were adjusted for and why they were included
6-7 Table 1-2
(b) Report category boundaries when continuous variables were categorized 6-7 Table 1-2 (c) If relevant, consider translating estimates of relative risk into absolute risk for
a meaningful time period
Other analyses 17 Report other analyses done—eg analyses of subgroups and interactions, and sensitivity analyses
Supplemental Digital Content 2-3
Discussion
Key results 18 Summarise key results with reference to study objectives 7 DISCUSSION
Limitations 19 Discuss limitations of the study, taking into account sources of potential bias or imprecision. Discuss both direction and magnitude of any potential bias
8-9 DISCUSSION
Interpretation 20 Give a cautious overall interpretation of results considering objectives, limitations, multiplicity of analyses, results from similar studies, and other relevant evidence
8 DISCUSSION
Generalisability 21 Discuss the generalisability (external validity) of the study results 8-9 DISCUSSION Other information
Funding 22 Give the source of funding and the role of the funders for the present study and, if applicable, for the original study on which the present article is based
1 Funding
*Give information separately for cases and controls in case-control studies and, if applicable, for exposed and unexposed groups in cohort and cross-sectional studies.
Note: An Explanation and Elaboration article discusses each checklist item and gives methodological background and published examples of transparent reporting. The STROBE checklist is best used in conjunction with this article (freely available on the Web sites of PLoS Medicine at http://www.plosmedicine.org/, Annals of Internal Medicine at http://www.annals.org/, and Epidemiology at http://www.epidem.com/).
Information on the STROBE Initiative is available at www.strobe-statement.org.
Supplemental Digital Content 2: Comparisons of baseline characteristics and outcomes between patients with no thrombocytopenia and
thrombocytopenia in MIMIC .Ⅲ
Variables Total (n = 17575) No TP (n = 13618)
TP (n=3957) p-value
1-2 days (n = 1589)
3-6 days (n = 1549)
>= 7days (n = 819)
Age, (years) 65 ± 17.1 64.9 ± 17.4 65.7 ± 16.5 66.7 ± 16.3 61.2 ± 15.5 < 0.001
Sex, men 9795 (55.7) 7489 (55) 961 (60.5) 892 (57.6) 453 (55.3) < 0.001
Hypertension 7667 (43.6) 6132 (45) 701 (44.1) 605 (39.1) 229 (28) < 0.001
Diabetes 4564 (26) 3631 (26.7) 405 (25.5) 366 (23.6) 162 (19.8) < 0.001
COPD 417 (2.4) 369 (2.7) 12 (0.8) 22 (1.4) 14 (1.7) < 0.001
Coronary 5039 (28.7) 3900 (28.6) 587 (36.9) 455 (29.4) 97 (11.8) < 0.001
ICU type < 0.001
CCU 2629 (15) 2194 (16.1) 189 (11.9) 177 (11.4) 69 (8.4)
CSRU 3675 (20.9) 2518 (18.5) 599 (37.7) 479 (30.9) 79 (9.6)
MICU 5840 (33.2) 4434 (32.6) 410 (25.8) 543 (35.1) 453 (55.3)
SICU 2986 (17) 2472 (18.2) 166 (10.4) 185 (11.9) 163 (19.9)
TSICU 2445 (13.9) 2000 (14.7) 225 (14.2) 165 (10.7) 55 (6.7)
Admission type < 0.001
ELECTIVE 2588 (14.7) 1901 (14) 328 (20.6) 291 (18.8) 68 (8.3)
EMERGENCY 14437 (82.1) 11319 (83.1) 1204 (75.8) 1203 (77.7) 711 (86.8)
URGENT 550 (3.1) 398 (2.9) 57 (3.6) 55 (3.6) 40 (4.9)
RRT 511 (2.9) 157 (1.2) 72 (4.5) 105 (6.8) 177 (21.6) < 0.001
Sofa score 4.6 ± 3.2 3.9 ± 2.7 5.9 ± 3.2 7.4 ± 3.4 8.5 ± 3.6 < 0.001
Vasopressor use 4410 (25.1) 2780 (20.4) 573 (36.1) 675 (43.6) 382 (46.6) < 0.001
Duration of TP, (days) 0 (0, 0) 0 (0, 0) 0.5 (0, 1.2) 3.5 (2.6, 4.7) 13.5 (9.2, 22.8) < 0.001 Biochemical indexes on ICU admission
Platelet count, (×109/L) 215.6 ± 111.3 243.1 ± 105.8 140.9 ± 67.4 112.6 ± 68.4 98.9 ± 70.4 < 0.001
Red blood cell, (×109/L) 3.6 ± 0.7 3.7 ± 0.6 3.4 ± 0.7 3.3 ± 0.7 3.1 ± 0.7 < 0.001
Hemoglobin, (g/dl) 10.8 ± 1.9 11 ± 1.9 10.5 ± 2 10.3 ± 2 9.9 ± 1.9 < 0.001
White blood cell, (×109/L)
12.3 ± 5.5 12.6 ± 5.2 11.7 ± 5.5 11 ± 6 10.1 ± 6.9 < 0.001
pH 7.4 ± 0.1 7.4 ± 0.1 7.4 ± 0.1 7.4 ± 0.1 7.4 ± 0.1 < 0.001
Bicarbonate, (mmol/L) 23.2 ± 4.2 23.6 ± 4 22.5 ± 4.1 21.6 ± 4.4 21.2 ± 5.1 < 0.001
lactate, (mmol/L) 1.8 (1.2, 2.8) 1.7 (1.2, 2.6) 2 (1.3, 3.3) 2.3 (1.5, 3.9) 2.4 (1.6, 4.1) < 0.001 Creatinine, (mmol/L) 79.56 (61.88,
114.92)
79.56 (61.88, 114.92)
79.56 (61.88, 114.92)
88.4 (61.88, 132.6) 114.92 (70.72, 203.32)
< 0.001
Urea level, (mmol/L) 18 (13, 29) 18 (12, 28) 19 (13, 29) 21 (14, 35) 27 (17, 48.5) < 0.001 Outcome
ICU free days 14.0 (0, 28) 18.5 (0, 28) 6.6 (0, 23) 0 (0, 21) 0 (0, 25) < 0.001
Ventilator free days 23.8 (17.0, 25.2) 24.1 (19.2, 25.3) 22.8 (12.3, 24.9) 21.0 (7.8, 24.7) 16.0 (7.8, 23.6) < 0.001 Hospital free days 17 (5, 21.2) 18 (8.6, 21.7) 15.9 (0.8, 20.3) 13.3 (0, 19.6) 0 (0, 11.5) < 0.001
Hospital mortality 2643 (15) 1676 (12.3) 306 (19.3) 361 (23.3) 300 (36.6) < 0.001
Data are presented as mean (SD) for normally distributed data and median [quartile 1, 3] for nonparametric data. Abbreviations: TP thrombocytopenia, COPD Chronic obstructive pulmonary disease, ICU intensive care unit, CCU coronary artery unit, CSRU cardiac surgery recovery unit, MICU medical ICU, SICU surgical ICU, TSICU trauma-neuro surgical ICU, RRT Renal replacement therapy, Sofa Sepsis-related Organ Failure Assessment.
Supplemental Digital Content 3: Cox’s proportional hazard models for hospital mortality in MIMIC Ⅲ
Adjusted HR (95% CI)
Duration of thrombocytopenia Model 1 Model 2
Age/Sex
Model 3
Age/Sex+Covariates+
initial platelet
None 1.00 Referenc 1.00 Referenc 1.00 Referenc
1–2 Days 1.48(1.31-1.67) 1.47(1.30-1.66) 1.59(1.39-1.81)
3–6 Days 1.55(1.31-1.67) 1.48(1.32-1.66) 1.43(1.25-1.62)
>=7 Days 1.33(1.17-1.51) 1.43(1.26-1.62) 1.17(1.01-1.35)
Abbreviations: 95% CI: 95% confidence interval; Adjusted HR: Adjusted hazard ratio from Cox proportional hazard model; Model 1:
unadjusted model; Model 2: adjusted for age, sex; Model 3: adjusted for age, sex, admission type, coronary, urea, lactate and initial platelet.
Supplemental Digital Content 4. Survival by duration of thrombocytopenia in MIMIC Ⅲ
The proportion of patients surviving from the time of ICU is plotted by the categories for the duration of thrombocytopenia.
Abbreviations: TP, thrombocytopenia; ICU, intensive care unit; MIMIC, Medical Information Mart for Intensive Care.
Supplemental Digital Content 5: Cox’s proportional hazard models for hospital mortality with a length of hospital stay of >7 days in MIMIC Ⅲ
Adjusted HR (95% CI)
Duration of thrombocytopenia Model 1 Model 2
Age/Sex
Model 3
Age/Sex+Covariates+
initial platelet
None 1.00 Referenc 1.00 Referenc 1.00 Referenc
1–2 Days 1.17(0.97-1.40) 1.17(0.97-1.40) 1.06(0.88-1.28)
3–6 Days 1.55(1.33-1.80) 1.47(1.26-1.71) 1.19(1.01-1.40)
>=7 Days 1.81(1.58-2.07) 1.96(1.71-2.24) 1.32(1.13-1.54)
Abbreviations: 95% CI: 95% confidence interval; Adjusted HR: Adjusted hazard ratio from Cox proportional hazard model; Model 1:
unadjusted model; Model 2: adjusted for age, sex; Model 3: adjusted for age, sex, renal replacement therapy, sofa score, admission type, lactate, creatinine, vasopressor and initial platelet.
Supplemental Digital Content 6. The patient with a length of hospital stay of >7 days survival by duration of thrombocytopenia in MIMIC Ⅲ
The proportion of patients surviving from the time of ICU is plotted by the categories for the duration of thrombocytopenia.
Abbreviations: TP, thrombocytopenia; ICU, intensive care unit; MIMIC, Medical Information Mart for Intensive Care.
