Concept: Identifying Intensive Care Unit (ICU) Episodes in the Hospital Abstracts Data

Introduction

This concept describes how intensive care unit (ICU) episodes of care can be identified in the Hospital Abstracts Data using the primary service codes and special care unit (SCU) codes that are recorded in the hospital abstract data.

Depending on the time frame of your study, different methods of identifying ICU episodes are required. Changes in the structure and content of the hospital abstract data occurred on April 1, 2004. Prior to this date, data was collected using the Hospital Abstract Users Manual (HAUM) method. From April 1, 2004 forward, data was collected using the Discharge Abstract Database (DAD) method. Both of the methods to identify ICU episodes from the hospital abstract data are illustrated below by providing example SAS code.

Identifying ICU Episodes Using the HAUM Data

*** HAUM data: include main patient service code and all service transfer codes ending in “90” which denotes ICU;
*** NICU is service code 5490;
*** Paediatric service codes include 2*90, 4*90, 5690, 6190, 6390, 6590, 6790, 6990, 7190, 7590;

array srv [7] primpsvc psvcd1-psvcd6;
icu_haum = 0;
do i = 1 to 7 while (icu_haum=0);

if substr(srv[i],3,2) = '90' then do;

icu_haum = 1;
icucd = srv[i];

end;

end;

HAUM Patient Service and Physician Service Code List


• A complete list of HAUM Patient Service and Physician Service Codes is available in the LINKS section below (Internal Access Only)

Identifying ICU Episodes Using the DAD Data

*** DAD data: include ICU special care unit codes, do not include step-down units;
*** NICU includes SCU codes 50, 51 (level 1), 52 (level 2), 53 (level 3, highest care) & 98;
*** Paediatric ICU is special unit code 70;

array scu [6] scu_unit1-scu_unit6;
icu_dad = 0;
do i = 1 to 6 while (icu_dad=0);

if scu[i] in
('10','20','25','30','35','40','45','50','51','52','53','60','70','80','98') then do;

icu_dad = 1;
icucd = scu[i];

end;

end;

DAD ICU and Special Care Unit (SCU) Codes and Descriptions


• A list of ICU and SCU codes and descriptions can be found in Appendix Table A2.1: Canadian Institute for Health Information (CIHI) Special Care Unit (SCU) Codes of The Epidemiology and Outcomes of Critical Illness in Manitoba deliverable by Garland et al. (2012).
  
  
• An updated list of Special Care Unit (SCU) Codes - April 2018 is available in the LINKS section below (Internal Access Only)

Cautions / Limitations

The method used to identify hospital ICU episodes may vary by project depending on a number of factors, including the time frame for the study and the focus of the study. In the HAUM data, ICU services are identified by the digits "90" in the last two characters of the relevant patient service variables. In the DAD data, ICU services are identified by specific values in the relevant Special Care Unit (SCU_UNIT#) variables.

There are specific codes for pediatric / neonatal ICUs (NICU) / SCUs, and these are different than the codes used to identify adult ICU units. You may want to include or exclude the NICU / paediatric ICU episodes, or adult ICU episodes, depending on the needs of your study.

It is suggested that you review and verify the service codes required for identifying ICU episodes prior to any research project.