Chronic kidney disease, risk of readmission, and progression to end-stage renal disease in 519,387 patients undergoing coronary artery bypass grafting

Objective

The association between chronic kidney disease and adverse outcomes after coronary artery bypass grafting is well established; in contrast, the association between chronic kidney disease and readmission has been less thoroughly investigated. We hypothesized that patients at higher chronic kidney disease stages have greater risk of readmission, poorer operative outcomes, and greater hospitalization cost.

Methods

Using the 2016-2018 Nationwide Readmissions Database, we identified 519,387 patients who underwent isolated coronary artery bypass grafting. Patients were stratified by chronic kidney disease stage based on International Classification of Diseases 10^th Revision classification. Multivariable logistic regression was used to assess risk factors for in-hospital mortality and 90-day readmission.

Results

Hospital readmission, in-hospital mortality, and cost progressively increased with worsening chronic kidney disease stage; patients with end-stage renal disease had the highest in-hospital mortality rate (7.2%), hospitalization costs ($59,616) (P < .001), and 90-day readmission rate (40%) (P < .001). Chronic kidney disease stage greater than 3 was associated with in-hospital mortality (odds ratio, 1.56, 95% confidence interval, 1.40-1.73; P < .001) and 90-day readmission (odds ratio, 1.66, 95% confidence interval, 1.56-1.76; P < .001). At 30 days after discharge, new-onset dialysis dependence was more frequent in patients readmitted with chronic kidney disease 4 to 5 (8.9%; n = 1495) than in patients with chronic kidney disease 1 to 3 (1.4%; n = 8623) and patients without chronic kidney disease (0.3%; n = 38,885). At 90 days after discharge, dialysis dependence increased to 11.1% (n = 1916) in readmitted patients with chronic kidney disease 4 to 5 but remained stable for patients with chronic kidney disease 1 to 3 (1.4%; n = 10,907) and patients without chronic kidney disease (0.3%; n = 50,200).

Conclusions

Chronic kidney disease stage is strongly associated with mortality, new-onset dialysis dependence, readmission, and higher cost after coronary artery bypass grafting. Patients with chronic kidney disease 4 and 5 and patients with end-stage renal disease are readmitted at the highest rates. Although further research is needed, a targeted approach may reduce costly readmissions and improve outcomes after coronary artery bypass grafting in patients with chronic kidney disease.

Medicaid expansion in Oregon and postpartum healthcare among people with and without prenatal substance use disorder

Background

People with a maternal substance use disorder (SUD) may experience a lack of access to necessary healthcare and more specifically, postpartum healthcare. It is not known whether increased insurance coverage introduced by Medicaid expansion has improved postpartum healthcare utilization among this population.

Methods

Oregon 2008-2016 birth certificates and Medicaid claims were used to examine whether continuous insurance enrollment and postpartum healthcare utilization increased post-Medicaid expansion in a population with and without SUD (n = 9,337). International Classification of Diseases codes were used to identify deliveries, SUD, and postpartum healthcare. Univariable and multivariable generalized linear regression with standard errors clustered by individual were used to estimate the association between Medicaid expansion and postpartum healthcare utilization, stratified by maternal SUD.

Results

Among the 10.3% with SUD, expansion was not associated with increased continuous enrollment or postpartum healthcare utilization. Among those without SUD, post-expansion deliveries were associated with increased continuous enrollment (+105.0 days; 95% CI=96.9-113.2), total (+4.4; 95% CI=2.9-6.0), postpartum (+0.3; 95% CI=0.2-0.4), inpatient (+0.9; 95% CI=0.7-1.1), outpatient (+2.3; 95% CI=1.4-3.3), office (+0.9; 95% CI=0.2-1.6), and emergency department (+0.3; 95% CI=0.1-0.5) visits. Among deliveries to postpartum people with SUD, 27.2% had opioid use disorder (OUD); expansion was associated with increased OUD medication use (12.0% vs 18.3%) and number of fills (6.7 vs 16.6).

Conclusions

Medicaid expansion in Oregon was only associated with increased Medicaid-financed healthcare utilization for postpartum people without SUD, with the exception of those with OUD, demonstrating the need for assessing various strategies to improve postpartum healthcare utilization.

Nationwide database analysis of one-year readmission rates after open surgical or thoracic endovascular repair of Stanford Type B aortic dissection

OBJECTIVE

We examined readmissions and resource use during the first postoperative year in patients who underwent thoracic endovascular aortic repair or open surgical repair of Stanford type B aortic dissection.

METHODS

The Nationwide Readmissions Database (2016-2018) was queried for patients with type B aortic dissection who underwent thoracic endovascular aortic repair or open surgical repair. The primary outcome was readmission during the first postoperative year. Secondary outcomes included 30-day and 90-day readmission rates, in-hospital mortality, length of stay, and cost. A Cox proportional hazards model was used to determine risk factors for readmission.

RESULTS

During the study period, type B aortic dissection repair was performed in 6456 patients, of whom 3517 (54.5%) underwent thoracic endovascular aortic repair and 2939 (45.5%) underwent open surgical repair. Patients undergoing thoracic endovascular aortic repair were older (63 vs 59 years; P < .001) with fewer comorbidities (Elixhauser score of 11 vs 17; P < .001) than patients undergoing open surgical repair. Thoracic endovascular aortic repair was performed electively more often than open surgical repair (29% vs 20%; P < .001). In-hospital mortality was 9% overall and lower in the thoracic endovascular aortic repair cohort than in the open surgical repair cohort (5% vs 13%; P < .001). However, the 90-day readmission rate was comparable between the thoracic endovascular aortic repair and open surgical repair cohorts (28% vs 27%; P = .7). Freedom from readmission for up to 1 year was also similar between cohorts (P = .6). Independent predictors of 1-year readmission included length of stay more than 10 days (P = .005) and Elixhauser comorbidity risk index greater than 4 (P = .033).

CONCLUSIONS

Approximately one-third of all patients with type B aortic dissection were readmitted within 90 days after aortic intervention. Surprisingly, readmission during the first postoperative year was similar in the open surgical repair and thoracic endovascular aortic repair cohorts, despite marked differences in preoperative patient characteristics and interventions.

Use of Post-Acute Care Services and Readmissions After Acute Myocardial Infarction Complicated by Cardiac Arrest and Cardiogenic Shock

OBJECTIVE

To evaluate post-acute care utilization and readmissions after cardiac arrest (CA) and cardiogenic shock (CS) complicating acute myocardial infarction (AMI).

METHODS

With use of an administrative claims database, AMI patients from January 1, 2010, to May 31, 2018, were stratified into CA+CS, CA only, CS only, and AMI alone. Outcomes included 90-day post-acute care (inpatient rehabilitation or skilled nursing facility) utilization and 1-year emergency department visits and readmissions.

RESULTS

Of 163,071 AMI patients, CA+CS, CA only, and CS only were noted in 3965 (2.4%), 8221 (5.0%), and 6559 (4.0%), respectively. In-hospital mortality was noted in 10,686 (6.6%) patients: CA+CS, 1935 (48.8%); CA only, 2948 (35.9%); CS only, 1578 (24.1%); and AMI alone, 4225 (2.9%) (P<.001). Among survivors, post-acute care services were used in 67,799 (44.5%), with higher use in the CS+CA cohort (1310 [64.6%]; hazard ratio [HR], 1.19; 95% CI, 1.06 to 1.33; P=.003) and CA cohort (2738 [51.9%]; HR, 1.27; 95% CI, 1.20 to 1.35; P<.001) but not in the CS cohort (3048 [61.2%]; HR, 1.03; 95% CI, 0.97 to 1.11; P=.35) compared with the AMI cohort (60,703 [43.3%]). Compared with the AMI cohort (48,990 [35.0%]), patients with CS only (2,085 [41.9%]; HR, 1.16; 95% CI, 1.10 to 1.22; P<.001) but not those with CA+CS (724 [35.7%]; HR, 1.07; 95% CI, 0.98 to 1.17; P=.14) had higher rates of readmissions (P=.03). Readmissions were lower in those with CA (1,590 [30.2%]; HR, 0.94; 95% CI, 0.89 to 0.99). Repeated AMI, coronary artery disease, and heart failure were the most common readmission reasons. There were no differences for emergency department visits.

CONCLUSION

CA is associated with increased post-acute care use, whereas CS is associated with increased readmission risk in AMI survivors.

Risk Factors for Unnecessary Antibiotic Prescribing for Acute Respiratory Tract Infections in Primary Care

Objective

To determine independent risk factors for inappropriate antibiotic prescribing for acute respiratory tract infections (ARIs) in internal medicine (IM) residency–based primary care offices.

Patients and Methods

A retrospective study was conducted to measure antibiotic prescribing rates, and multivariable analysis was utilized to identify predictors of inappropriate prescribing among patients presenting to IM residency–based primary care office practices. Patients with an office visit at either of 2 IM residency–based primary care office practices from January 1, 2016, through December 31, 2016, with a primary encounter diagnosis of ARI were included.

Results

During the study period, 911 unique patient encounters were included with 518 for conditions for which antibiotics were considered always inappropriate. Antibiotics were not indicated in 85.8% (782 of 911) of encounters. However, antibiotics were prescribed in 28.4% (222 of 782) of these encounters. Inappropriate antibiotic prescribing occurred in 111 of 518 (21.4%) encounters for conditions for which antibiotics are always inappropriate. Using multivariable logistic regression analysis to assess for independent risk factors when adjusted for other potential risk factors for office visits at which antibiotics were not indicated, IM resident–associated visits (odds ratio, 0.25; 95% CI, 0.18-0.36) was the only variable independently associated with lower risk of inappropriate antibiotic prescribing.

Conclusion

For ARI visits at which antibiotics were not indicated, IM resident comanagement was associated with lower rates of inappropriate prescribing.

Opioid-Induced Hypogonadism in the United States

Objective

To examine the incidence of screening, diagnosis, and treatment of hypogonadism among men treated with opioids in the United States.

Patients and Methods

Using one of the nation's largest commercial insurance databases, we identified 53,888 men aged 20 years or older who had 90 or more days of opioid prescriptions in a single 12-month period between January 1, 2010, and December 31, 2017, with no history of hypogonadism or testosterone therapy in the preceding 12 months. We matched this cohort to 53,888 men with 14 or fewer days of opioid prescriptions based on age, opioid initiation date, opioid indication, and comparable exclusion criteria. We assessed whether men, 14 or fewer days after initiation of opioid treatment, received a serum testosterone test, a diagnosis of hypogonadism, or a prescription for testosterone therapy. All men were followed up until they lost coverage from the commercial insurance plan, experienced one of the study outcomes, or the end of study (December 31, 2017).

Results

In the multivariable analyses-adjusting for age, year of opioid initiation, region, comorbid disease, glucocorticoid use, and health care utilization-the 53,888 prolonged opioid users, in comparison with 53,888 short-term users, had an increased incidence of serum testosterone screening (5991 [17.15%; 95% CI, 16.70%-17.61%] vs 3514 [11.55%; 95% CI, 11.11%-12.01%] at 5 years; hazard ratio [HR], 1.46; 95% CI, 1.38-1.55), hypogonadism diagnosis (3125 [9.44%; 95% CI, 9.09%-9.80%] vs 1421 [4.85%; 95% CI, 4.55%-5.16%; HR, 1.74; 95% CI, 1.60-1.90]), and receipt of testosterone therapy (1919 [5.76%; 95% CI, 5.49%-6.05%] vs 631 [2.21%; 95% CI, 2.04%-2.43%; HR, 2.41; 95% CI, 2.13-2.74]). Each of these findings persisted across multiple sensitivity analyses.

Conclusion

Prolonged opioid exposure was associated with increased rates of screening, diagnosis, and treatment for opioid-induced hypogonadism, but these rates were much lower than expected based on previous serum-based studies.