Comorbidities up frailty risk in older adults, worsen surgical outcomes

In older adults up for elective noncardiac surgery, having more multimorbidities aggravates the risk of frailty, in turn worsening surgical outcomes, according to a recent Singapore study.

“Only a small proportion of those with multimorbidity accumulate enough biological deficits to develop frailty, putting them at higher risk than [those] with solely multimorbidity or frailty,” said the researchers, pointing out that “[d]ementia and depression are comorbidities with strong associations that have yet to see coordinated interventional efforts in the preoperative setting.”

The single-centre retrospective cohort study included 1,396 participants (mean age 75.8±4.7 years, 52.8 percent women) who had undergone preoperative evaluation at the Singapore General Hospital. Patients were eligible if they were >70 years of age and scheduled for elective noncardiac surgery. Frailty was assessed using the Edmonton Frail Scale (EFS).

Most of the participants (n=1,008) were nonfrail, with an EFS score of 0–5. The remaining 388 were deemed to be frail, with EFS scores of 6–7 (mildly frail), 8–9 (moderately frail), and >9 (severely frail); the overall incidence of frailty was 27.8 percent. Multimorbidity was detected in 63.4 percent of patients. [Cureus 2021;13:e15033]

Unadjusted analysis found the following comorbidities to be associated with frailty: diabetes mellitus (DM) and accompanying insulin treatment, chronic kidney disease (CKD), end-stage renal failure (ESRF), ischaemic heart disease (IHD), hypertension, congestive heart failure (CHF), peripheral vascular disease (PVD), dementia, depression, haemiplegia, peptic ulcer disease (PUD), cerebrovascular accident/transient ischaemic attack (CVA/TIA), and anaemia.

Multivariable regression analysis revealed that of these, dementia seemed to be the strongest risk factor for frailty, increasing its odds by over sixfold (adjusted odds ratio [aOR], 6.38, 95 percent confidence interval [CI], 2.75–16.11; p<0.001).

Other independent comorbid risk factors included DM (aOR, 1.69, 95 percent CI, 1.28–2.24; p<0.001), CKD (aOR, 1.47, 95 percent CI, 1.03–2.09; p=0.034), ESRF (aOR, 3.58, 95 percent CI, 1.79–7.49; p<0.001), moderate anaemia (aOR, 2.11, 95 percent CI, 1.44–3.09; p<0.001), a history of CVA/TIA (aOR, 1.87, 95 percent CI, 1.2–2.9), depression (aOR, 3.82, 95 percent CI, 1.54–9.97; p=0.005), and PUD (aOR, 1.98, 95 percent CI, 1.06–3.67; p=0.031).

Age (aOR, 1.07, 95 percent CI, 1.04–1.11; p<0.001) and being female (aOR, 1.67, 95 percent CI, 1.25–2.22; p<0.001) were likewise significant correlates of frailty.

Multimorbidity also emerged as a significant risk factor for frailty (OR, 2.93, 95 percent CI, 2.23–3.87), an interaction that strengthened as the number of comorbid conditions increased. For instance, having three instead of two comorbidities more than doubled the OR, jumping from 2.45 (95 percent CI, 1.43–4.47; p<0.002) to 4.85 (95 percent CI, 2.79–8.92; p<0.001).

Having more than five comorbidities magnified the risk of frailty by over 10 times (OR, 11.28, 95 percent CI, 4.71–28.37; p<0.001).

“Distinguishing the contributions of different domains in EFS is valuable to policymakers in deciding the resources needed to deliver tailored care,” the researchers said. “Our results show the main contributing domains were those involving a loss of function, ie, the ability to perform activities of daily living and the number of hospital admissions in the past year.”

“This suggests that loss of functional independence may have a disproportionate impact on the onset of frailty in older people,” they added.