Association of the Intermountain Risk Score with major adverse health events in patients positive for COVID-19: an observational evaluation of a US cohort

Abstract

ObjectivesThe Intermountain Risk Score (IMRS), composed using published sex-specific weightings of parameters in the complete blood count (CBC) and basic metabolic profile (BMP), is a validated predictor of mortality. We hypothesised that IMRS calculated from prepandemic CBC and BMP predicts COVID-19 outcomes and that IMRS using laboratory results tested at COVID-19 diagnosis is also predictive.DesignProspective observational cohort study.SettingPrimary, secondary, urgent and emergent care, and drive-through testing locations across Utah and in sections of adjacent US states. Viral RNA testing for SARS-CoV-2 was conducted from 3 March to 2 November 2020.ParticipantsPatients aged ≥18 years were evaluated if they had CBC and BMP measured in 2019 and tested positive for COVID-19 in 2020.Primary and secondary outcome measuresThe primary outcome was a composite of hospitalisation or mortality, with secondary outcomes being hospitalisation and mortality separately.ResultsAmong 3883 patients, 8.2% were hospitalised and 1.6% died. Subjects with low, mild, moderate and high-risk IMRS had the composite endpoint in 3.5% (52/1502), 8.6% (108/1256), 15.5% (152/979) and 28.1% (41/146) of patients, respectively. Compared with low-risk, subjects in mild-risk, moderate-risk and high-risk groups had HR=2.33 (95% CI 1.67 to 3.24), HR=4.01 (95% CI 2.93 to 5.50) and HR=8.34 (95% CI 5.54 to 12.57), respectively. Subjects aged <60 years had HR=3.06 (95% CI 2.01 to 4.65) and HR=7.38 (95% CI 3.14 to 17.34) for moderate and high risks versus low risk, respectively; those ≥60 years had HR=1.95 (95% CI 0.99 to 3.86) and HR=3.40 (95% CI 1.63 to 7.07). In multivariable analyses, IMRS was independently predictive and was shown to capture substantial risk variation of comorbidities.ConclusionsIMRS, a simple risk score using very basic laboratory results, predicted COVID-19 hospitalisation and mortality. This included important abilities to identify risk in younger adults with few diagnosed comorbidities and to predict risk prior to SARS-CoV-2 infection.

Intermittent fasting and changes in clinical risk scores: Secondary analysis of a randomized controlled trial

“…This study reports an increase in a risk score that predicts mortality and supports the need for safety evaluation based on changes in IMRS, a powerful quantitative, objective, temporally-dynamic risk score [ [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] ]. When IMRS is measured multiple times longitudinally, those serial measurements were found previously to provide independent risk information [ 19 , 22 ].…”

“…The proposal that the observed IMRS increase measures a trigger for intermediate- and long-term disease risk reduction and longevity improvement is, in part, suggested by the minimal clinical significance of the observed median 1.0 (mean: 0.78) increase in IMRS (theoretical IMRS range in females: −5 to 28; males: −1 to 28) [ 12 ]. Prior literature shows that increase represents a minor change in actual mortality [ [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] ]. In particular, a study of the change score of IMRS from baseline to a second IMRS measurement 6–24 months later revealed an average IMRS increase of 1.6 and 2.0 for female and male patients, respectively (2.05–2.56 fold higher than the average IMRS change observed here), whose baseline IMRS values were in a low-risk range similar to the range of IMRS values in this WONDERFUL Trial study [ 19 ].…”

“…Further, the trial sample size was not large, detailed dietary intake data were not collected, and the endpoints were not clinical events but risk scores for such events [ 26 ]. Also, participants were community-dwelling adults with some cardiometabolic risk factors but no cardiovascular diseases, cancer, respiratory conditions, or other major causes of death, and since most IMRS studies evaluated outpatients and inpatients [ 12 , [14] , [15] , [16] , [17] , [18] , [19] ], the meaning of a 0.78 point IMRS increase for apparently healthy people and the generalizability of findings to other populations is unknown. Strengths of the study were the low-frequency 24-h fasting regimen that evoked improvements in cardiometabolic risk factors even when weight was not significantly decreased [ 26 ], and the ad libitum control of subjects utilizing their standard dietary choices that reflect real-world behaviors.…”

“…IMRS is a widely-validated quantitative longevity prediction tool computed from objective, standardized clinical laboratory factors in the complete blood count (CBC) and basic metabolic profile (BMP) [ [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] ]. IMRS was developed for clinical mortality risk assessment in outpatients and inpatients [ 12 ], and has a similar to superior ability to predict mortality compared to comorbidity scores [ 15 , 16 , 20 ].…”