Defining ICD-10 surrogate variables to estimate the modified frailty index: a Delphi-based approach

Background There are currently no validated globally and freely available tools to estimate the modified frailty index (mFI). The widely available and non-proprietary International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) coding could be used as a surrogate for the mFI. We aimed to establish an appropriate set of the ICD-10 codes for comorbidities to be used to estimate the eleven-variable mFI. Methods A three-stage, web-based, Delphi consensus-building process among a panel of intensivists and geriatricians using iterative rounds of an online survey, was conducted between March and July 2021. The consensus was set a priori at 75% overall agreement. Additionally, we assessed if survey responses differed between intensivists and geriatricians. Finally, we ascertained the level of agreement. Results A total of 21 clinicians participated in all 3 Delphi surveys. Most (86%, 18/21) had more than 5-years’ experience as specialists. The agreement proportionately increased with every Delphi survey. After the third survey, the panel had reached 75% consensus in 87.5% (112/128) of ICD-10 codes. The initially included 128 ICD-10 variables were narrowed down to 54 at the end of the 3 surveys. The inter-rater agreements between intensivists and geriatricians were moderate for surveys 1 and 3 (κ = 0.728, κ = 0.780) respectively, and strong for survey 2 (κ = 0.811). Conclusions This quantitative Delphi survey of a panel of experienced intensivists and geriatricians achieved consensus for appropriate ICD-10 codes to estimate the mFI. Future studies should focus on validating the mFI estimated from these ICD-10 codes. Trial registration Not applicable. Supplementary Information The online version contains supplementary material available at 10.1186/s12877-022-03063-x.

* This form is collecting email addresses. Change settings The 11 variables that constitute the mFI are -Functional status (not independent) 1 .
. History of hypertension requiring medication 2 History of chronic obstructive pulmonary disease or pneumonia 3 .
History of impaired sensorium 4 .
. History of diabetes mellitus 5 6 . History of myocardial infarction 7 History of congestive heart failure . History of stroke with neurologic deficit . 8 History of percutaneous angiographic intervention, angina or stenting . 9 10 . History of Peripheral vascular disease or ischemic rest pain 11 . History of Transient ischaemic attack or stroke However, nine of the eleven mFI items refer to medical co-morbidities that do not conform to the frailty 2011 expert consensus statement: "frailty is a multidimensional construct consisting of six domains (physical performance, gait speed, mobility, nutritional status, mental health, and cognition)". Moreover, two of the eleven mFI variables ('not independent of functional status' and 'impaired sensorium') did not have readily available ICD-10 codes. We have included all possible ICD-10 codes pertinent to each of the 11 mFI variables. We aim to refine these codes to establish an appropriate set of ICD-10 codes that could be used in the mFI evaluation.
We have provided the actual NSQIP definitions that was used for every variable. However, if need further clarification, please feel free to click the link below for the detailed NSQIP data dictionary. Variable 3: Please advise if these ICD-10 codes represent "History of chronic obstructive * pulmonary disease or pneumonia". ACTUAL definition of the variable as designed, which are found in the NSQIP data dictionary.
Medical record must document that there is a historical or current diagnosis of COPD AND at least one of the following, in the preceding 30 days: Functional disability from COPD (e.g., dyspnea, inability to perform ADLs) Or Requires chronic bronchodilator therapy with oral or inhaled agents or other medication specifically targeted to this disease Or Hospitalization in the past for treatment of COPD Or An FEV1 of <75% of predicted on a prior pulmonary function test (PFT). Patients whose only pulmonary disease is asthma, an acute and chronic inflammatory disease of the airways resulting in bronchospasm are not included. Patients with diffuse interstitial fibrosis, sarcoidosis, or silicosis are not included.  Purpose: To calculate the eleven co-morbidities modified frailty index (mFI) using the pertinent ICD-10 codes required to identify each of the eleven co-morbidities as an approximation. The ICD-10 codes were obtained from the Australian-Refined Diagnosis Related Groups (AR-DRG) upon patients' discharge from the hospital.
We have included all possible ICD-10 codes pertinent to each of the 11 mFI variables. Many have answered 'Maybe'. In Delphi Round 2 I have removed the 'Maybe' option. We are hoping for a 'YES' and 'NO' from you. Please mark these ICD-10 codes as variables that represent a comorbidity variable rather than as a frailty marker.
As Delphi Panel Members, on behalf of my co-authors, I request your help again.
Delphi Survey: This is the second survey.
Your participation is voluntary. By participating, you are providing consent for the study results to be used for publication. You will not receive any monetary benefits. You will be acknowledged in the manuscript as a Delphi Panel Member.
Only the researchers will be able to link your responses to your email address. surgery but subsequently found to be predictive of increased mortality and length of stay in a large Brazilian cohort of critically ill patients. The mFI is calculated by allocating one point for each of the eleven comorbidities (that encompasses previous medical events and functional capacity). The mFI categorises patients as non-frail if score=0-2, or frail i the score is ≥3.
The 11 variables that constitute the mFI are -1. Functional status (not independent) 2. History of hypertension requiring medication 3. History of chronic obstructive pulmonary disease or pneumonia 4. History of impaired sensorium 5. History of diabetes mellitus 6. History of myocardial infarction 7. History of congestive heart failure 8. History of stroke with neurologic deficit 9. History of percutaneous angiographic intervention, angina or stenting 10. History of Peripheral vascular disease or ischemic rest pain 11. History of Transient ischaemic attack or stroke However, nine of the eleven mFI items refer to medical co-morbidities that do not conform to the frailty 2011 expert consensus statement: "frailty is a multidimensional construct consisting of six domains (physical performance, gait speed, mobility, nutritional status, mental health, and cognition)". Moreover, two of the eleven mFI variables ('not independent of functional status' and 'impaired sensorium') did no have readily available ICD-10 codes. We have included all possible ICD-10 codes pertinent to each of the 11 mFI variables. We aim to refine these codes to establish an appropriate set of ICD-10 codes that could be used in the mFI evaluation.
We have provided the actual NSQIP definitions that were used for every variable. However, if need further clarification, please feel free to click the link below for the detailed NSQIP data dictionary.

4.
Variable 3: Please advise if these ICD-10 codes represent "History of chronic obstructive pulmonary disease or pneumonia". 7 ICD-10 codes that obtained 75% consensus has been removed. *

8.
Variable 7: Please advise if these ICD-10 codes represent "History of congestive heart failure". 75% Consensus was not obtained in any of these ICD-10 codes. * 11. Variable 10: Please advise if these ICD-10 codes represent "History of percutaneous angiographic intervention, angina or stenting". 75% Consensus was obtained in 1 ICD-10 code.

12.
Variable 11: Please advise if these ICD-10 codes represent "History of Peripheral vascular disease or ischemic rest pain". 75% Consensus was not obtained in any of these ICD-10 codes. * As Delphi Panel Members, on behalf of my co-authors, I request your help again. I promise this will be the last survey.
Purpose: To calculate the eleven co-morbidities modified frailty index (mFI) using the pertinent ICD-10 codes required to identify each of the eleven co-morbidities as an approximation. The ICD-10 codes were obtained from the Australian-Refined Diagnosis Related Groups (AR-DRG) upon patients' discharge from the hospital. We have included all possible ICD-10 codes pertinent to each of the 11 mFI variables.
Delphi Survey: This is the third and final survey. We will accept a majority rule, for those variables that have not reached a consensus. I've only included the 38 variables that we do not have a consensus on yet. In Delphi Round 3, I have introduced a 5-point Likert scale. Please mark these ICD-10 codes as variables that represent a comorbidity variable rather than as a frailty marker.
Your participation is voluntary. By participating, you are providing consent for the study results to be used for publication. You will not receive any monetary benefits. You will be acknowledged in the manuscript as a Delphi Panel Member.
Only the researchers will be able to link your responses to your email address.
The time taken to complete the survey is approximately 5-6 minutes Background: Frailty, across the adult age spectrum, is common in patients admitted to intensive care units (ICU), and patients with frailty generally have poorer outcomes. The validated clinical frailty scale (CFS) is the most commonly used scale in ICU patients globally.
Frailty index-based assessment may be difficult to deliver by the critical care team on a routine basis. Shorter modified versions have been validated in other countries. The modified frailty index (mFI) was created by mapping eleven comorbidity variables contained within the National Surgical Quality Improvement Program (NSQIP) database contained within the original 70-item Canadian Study of Health and Ageing Frailty Index. The mFI was originally created for patients having surgery but subsequently found to be predictive of increased mortality and length of stay in a large Brazilian cohort of critically ill patients. The mFI is calculated by allocating one point for each of the eleven co-morbidities (that encompasses previous medical events and