*! version 1.2.0 18 August 2024

Title

pim3 -- a command to calculate the Paediatric Index of Mortality 3 (PIM3) score

Syntax

pim3 newvar
[if] [in]
,
sbp(varname) mv(varname) pao2(varname) fio2(varname)
pupils(varname) baseexcess(varname) elective(varname)
procedure(varname)
[lowrisk(varname) highrisk(varname) veryhighrisk(varname)]
[risk(varname)]
[options]

Cardiovascular
sbp(varname) systolic blood pressure (mmHg)

Respiratory
mv(varname) mechanical ventilation within first hour (0=no, 1=yes)

pao2(varname) partial pressure of oxygen in arterial blood (mmHg)

fio2(varname) fraction of inspired oxygen (0.21 - 1.0 or 21% - 100%)

Neurologic
pupils(varname) pupil reaction to light (0=both reactive, 1=both fixed and dilated)

Renal
baseexcess(varname) base excess in arterial or capillary blood (mmol/L)

Admission Reason
elective(varname) elective admission (0=no, 1=yes)

procedure(varname) reason for ICU admission (0-3)

Risk category
lowrisk(varname) low-risk diagnosis (0=no, 1=yes)

highrisk(varname) high-risk diagnosis (0=no, 1=yes)

veryhighrisk(varname) very high-risk diagnosis (0=no, 1=yes)

----- or -----
risk(varname) risk category (0-3)

Debugging Options
noimputation treat missing values as missing

novalidation skip out-of-range data checks

trace turn on trace for debugging

Description

pim3 calculates the Paediatric Index of Mortality 3 (PIM3) score. The score is an outcome prognostication tools that has been used
extensively in clinical care and research to calculate the expected mortality and control for illness severity in pediatric intensive care units.

See Citation for proper attribution.

Options

For all required variables, if there is data missing you will receive a warning. The calculation will still be performed using normal values for the age group.

Cardiovascular

sbp(varname) specifies the systolic blood pressure in mmHg.

Respiratory

mv(varname) specifies whether mechanical ventilation was used within the first hour of admission. The variable must be coded as 0 = No | 1 = Yes.

pao2(varname) specifies the name of the partial pressure of oxygen (PaO2) variable in mmHg.

fio2(varname) specifies the name of the fraction of inspired oxygen (FiO2) variable. It can be entered as 0.21-1.0 or 21-100.

Neurologic

pupils(varname) specifies the pupillary reaction to light. The variables must be coded as: 0 = reactive | 1 = both fixed

Renal

baseexcess(varname) specifies the base excess in arterial or capillary blood in mmol/L.

Admission Reason

elective(varname) specifies whether the admission was elective. The variable must be coded as 0 = No | 1 = Yes.

procedure(varname) specifies whether recovery from surgery or a procedure is the main reason for ICU admission (0-3). The variable must be coded as 0 = Recovery from procedure IS NOT the main reason for ICU admission | 1 = Recovery from a bypass cardiac procedures. | 2 = Recovery from a non-bypass cardiac procedure | 3 = Recovery from a noncardiac procedure

See the remarks section for more information.

You must specify either the risk(varname) or the three risk stratification variables: lowrisk(varname), highrisk(varname), and veryhighrisk(varname).

lowrisk(varname) specifies whether the patient has a low-risk diagnosis. The variable must be coded as 0 = No | 1 = Yes.

highrisk(varname) specifies whether the patient has a high-risk diagnosis. The variable must be coded as 0 = No | 1 = Yes.

veryhighrisk(varname) specifies whether the patient has a very high-risk diagnosis. The variable must be coded as 0 = No | 1 = Yes.

risk(varname) specifies the risk category (0-3). The variable must be coded as 0 = No low risk, high risk or very high risk diagnosis | 1 = Low risk diagnosis | 2 = High risk diagnosis | 3 = Very high risk diagnosis

See the remarks section for more information.

Options

noimputation calculated score will be set to missing if any of the included variables are missing. The default is to use normal physiological values for age when values are missing.

novalidation specifies that out-of-range data checks should be skipped.
The default is to treat out-of-range values as missing.

trace turns on trace for debugging purposes.

Remarks

The procedure variable should be coded as follows:

0: Recovery from procedure IS NOT the main reason for ICU admission

1: Recovery from a bypass cardiac procedures the main reason for ICU admission

2: Recovery from a non-bypass cardiac procedure

3: Recovery from a noncardiac procedure

If using the risk variable instead of the individual risk stratification variables, it should be coded as follows:

0: No low, high or very high risk diagnosis

1: Low risk diagnosis

2: High risk diagnosis

3: Very high risk diagnosis

By default, the command performs data validation and imputes missing values with normal physiological values. These behaviors can be modified using the novalidation and noimputation options.

References

[1] Straney L, Clements A, Parslow RC, et al. Paediatric Index of Mortality 3: An Updated Model for Predicting Mortality in Pediatric Intensive Care. Ped Crit Care. 2013;14(7):673-681.

Citation

Please cite this command as:

Azamfirei R, Mennie C, Fackler J, Kudchadkar SR. Pediatric Critical Care Illness Severity Toolkit: Stata Commands for Calculation of Pediatric Index of Mortality and Pediatric Logistic Organ Dysfunction Scores. JCCM. 2024;10(1):16-18. | DOI: 10.2478/jccm-2023-0033

Authors

Razvan Azamfirei | Email: stata@azamfirei.com

Colleen Mennie

James Fackler

Sapna R. Kudchadkar

License

Copyright 2023 Razvan Azamfirei

Licensed under the Apache License, Version 2.0 (the"License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at:

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

See the License for the specific language governing permissions and limitations under the License.

Also see

pelod2, prismscore, pccmtoolkit