Association between anaemia and hospital readmissions in patients undergoing major surgery requiring postoperative intensive care

Abstract

Summary Anaemia is a common sequela of surgery, although its relationship with patient recovery is unclear. The goal of this investigation was to assess the associations between haemoglobin concentrations at the time of hospital discharge following major surgery and early post‐hospitalisation outcomes, with a primary outcome of 30 day unanticipated hospital readmissions. This investigation includes data from two independent population‐based observational cohorts of adult surgical patients (aged ≥ 18 years) requiring postoperative intensive care unit admission between 1 January 2010 and 31 December 2019 in hospitals in Olmsted County, Minnesota, and between 1 July 2010 and 30 June 2017 in the Kaiser Permanente Northern California integrated healthcare system, California. Cox proportional hazards models assessed the associations between discharge haemoglobin concentrations (per 10 g.l–1) and outcomes, with prespecified multivariable adjustment. A total of 3260 patients were included from Olmsted County hospitals and 29,452 from Kaiser Permanente Northern California. In adjusted analyses, each 10 g.l–1 decrease in haemoglobin at hospital discharge was associated with a 9% (hazard ratio 1.09, 95%CI 1.02–1.18; p = 0.014) and 8% increase (hazard ratio 1.08, 95%CI 1.06–1.11; p < 0.001) in the hazard for readmission within 30 days in Olmsted County and Kaiser Permanente Northern California, respectively. In a sensitivity analysis exploring relationships across varying levels of pre‐operative anaemia severity, these associations remained consistent, with lower discharge haemoglobin concentrations associated with higher readmissions irrespective of pre‐operative anaemia severity. Anaemia at hospital discharge in surgical patients requiring postoperative intensive care is associated with increased rates of hospital readmission in two large independent cohorts. Future studies are necessary to evaluate strategies to prevent and/or treat anaemia in these patients for the improvement of post‐hospitalisation outcomes.

Postoperative anaemia increases unplanned readmission: an international prospective cohort study of patients undergoing major abdominal surgery

“…In this international prospective study (POSTVenTT), anaemia after major surgery was common and had a negative impact on patient recovery, with an increased risk of unplanned readmission and increased frailty at 30 days. These results confirm the findings of previous retrospective database analyses and build on the secondary findings seen in the PREVENTT and FIT RCTs, including the reanalysis of trials which suggested a greater risk of mortality or disability up to 90 days following surgery, postoperative delirium and a longer length of stay 9 , 10 , 22 .…”

“…However, an interesting finding in both trials was that the greatest treatment effect was increased haemoglobin levels at 6–8 weeks after surgery, which was associated with a reduction in unplanned hospital readmissions 7 , 8 . The association of postoperative anaemia and worse patient recovery was also observed in a large database analysis of patients undergoing surgery 9 . In a reanalysis of a large perioperative clinical trial, postoperative anaemia was associated with an increased risk of death and disability at 90 days 10 .…”

Blood count derangements after sepsis and association with post-hospital outcomes

“…Additional work will be required to validate the utility of these parameters in this capacity. This study also adds to several large studies (44,45) showing that Hgb is an important predictor of long-term outcomes among survivors of sepsis and/or critical illness. However, as our study does not evaluate causation, additional work is needed to determine if anemia at hospital discharge contributes directly to longterm outcomes.…”

“…Several retrospective studies have identified Hgb as an important prognostic biomarker in sepsis survivors when measured on hospital admission or discharge (8, 37, 40-44). Among survivors of sepsis and critical illness, lower discharge Hgb is an independent risk factor for 30-day rehospitalization and posthospitalization mortality (37,40,41,44,45). Among patients discharged with anemia after critical illness, impaired recovery of Hgb is also associated with higher rates of 1-year rehospitalization and death (43).…”

National Estimates of Short- and Longer-Term Hospital Readmissions After Major Surgery Among Community-Living Older Adults

“… 32 , 33 Despite this, currently available estimates of hospital readmissions after major surgery in older persons are inadequate for several reasons. Prior studies have been limited to a subset of specific surgical procedures 2 , 9 , 34 , 35 , 36 or age groups, 9 , 37 , 38 , 39 are often restricted to a single institution 40 , 41 or are not otherwise nationally representative, 39 , 42 , 43 lack data beyond 30 days, 2 , 12 , 39 , 44 or have not evaluated clinically relevant geriatric subgroups. 10 , 35 , 43 , 45 Furthermore, prior estimates of hospital readmission based on CMS data 2 , 15 , 46 were based solely on FFS beneficiaries.…”