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Treatment for Frailty Does Not Improve Complication Rates in Corrective Surgery for Adult Spinal Deformity

Yagi, Mitsuru, MD, PhD∗,†,‡; Michikawa, Takehiro, MD, PhD§; Hosogane, Naobumi, MD, PhD‡,¶; Fujita, Nobuyuki, MD, PhD∗,‡; Okada, Eijiro, MD, PhD∗,‡; Suzuki, Satoshi, MD, PhD∗,‡; Tsuji, Osahiko, MD, PhD∗,‡; Nagoshi, Narihito, MD, PhD∗,‡; Asazuma, Takashi, MD, PhD; Tsuji, Takashi, MD, PhD‡,||; Nakamura, Masaya, MD, PhD∗,‡; Matsumoto, Morio, MD, PhD∗,‡; Watanabe, Kota, MD, PhD∗,‡

doi: 10.1097/BRS.0000000000002929
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Study Design. A retrospective multicenter database review of 240 consecutive patients at least 21 years of age (mean 58 ± 17, range 22–79) who underwent surgery for adult spinal deformity (ASD) and were followed at least 2 years.

Objective. To investigate how treatment for frailty affects complications in surgery for ASD.

Summary of Background Data. Several recent studies have focused on associations between frailty and surgical complications. However, it is not clear whether treating frailty affects complication rates in surgery for ASD.

Methods. Patients were categorized as robust (R group), prefrail, or frail based on the modified frailty index (mFI); prefrail and frail patients were divided by good control of frailty (G group), defined as treatment following the appropriate guidelines for each mFI factor, or poorly controlled frailty (PC group). We compared clinical outcomes and perioperative and 2-year complications between the three groups.

Results. Of the 240 patients, 142 (59%) were robust, 81 (34%) were prefrail, and 17 (7%) were frail. Among the frail and prefrail patients, 71 (72%) were classified as G and 27 (28%) as PC. The perioperative complication rate was similar in the G and PC groups (32% vs. 37%) but was significantly lower in the R group (15%, P < 0.01). The age- and sex-adjusted odds ratio for 2-year complications was not different in the P group when the G group was referenced (odds ratio 1.3 [0.5–3.2], P = 0.63). In the G and PC groups, which had similar 2-year outcomes, the Scoliosis Research Society-22 function and total scores were significantly lower than in the R group (function: R 3.9 ± 0.7, G 3.5 ± 0.7, P 3.3 ± 0.6; total: R 3.9 ± 0.6, 3.7 ± 0.7, 3.4 ± 0.6; P < 0.01).

Conclusion. Regardless of its treatment status, frailty increases the risk of complications and inferior clinical outcomes in ASD surgery. Surgeons should routinely evaluate frailty and inform patients of frailty-related risks when considering surgery for ASD.

Level of Evidence: 4

Retrospective review of 240 surgically consecutive ASD patients from multicenter database revealed that regardless of its treatment status, frailty increases the risk of complications and inferior clinical outcomes in ASD surgery. Surgeons should routinely evaluate frailty and inform patients of frailty-related risks when considering surgery for ASD.

Department of Orthopedic Surgery, Keio University School of Medicine

Department of Orthopedic Surgery, National Hospital Organization Murayama Medical Center

Keio Spine Research Group

§Department of Environmental and Occupational Health, School of Medicine, Toho University

Department of Orthopedic Surgery, Kyorin University School of Medicine, Tokyo

||Department of Orthopedic Surgery, Fujita Health University, Nagoya, Japan.

Address correspondence and reprint requests to Kota Watanabe, MD, PhD, Department of Orythopedic Surgey, Keio University School of Medicine, 35 Shinanomachi, Shinjyuku-ku Tokyo Japan Kota Watanabe; E-mail: KW19751@keio.jp

Received 28 September, 2018

Revised 9 October, 2018

Accepted 17 October, 2018

The manuscript submitted does not contain information about medical device(s)/drug(s).

No funds were received in support of this work.

Relevant financial activities outside the submitted work: grants.

Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Website (www.spinejournal.com).

Surgery to correct adult spinal deformity (ASD) is invasive and carries a substantial risk of complications.1–6 Appropriate patient selection and good surgical decisions are key to successful treatment.1–7 Several risk factors have been reported for surgical complications and inferior clinical outcomes,1–7 including frailty.7–12

In 1956, Parfentjev13 described frailty as a clinically recognizable state of increased vulnerability resulting from an aging-associated decline in reserves and function across multiple systems, such that the ability to cope with everyday or acute stressors is compromised. Several studies describe the importance of frailty on outcomes in general surgery.14–17 A systematic review by Abdullahi et al16 concluded that assessing frailty may improve the preoperative work-up and optimize risk stratification measures for patients undergoing cardiothoracic procedures. A systematic review by Eamer et al17 describe the preoperative frailty assessment as a promising tool for predicting surgical complications in general surgery in an elderly population. Although frailty has long been recognized as an established clinical syndrome, the effect of frailty on outcomes of elective spine surgery is still under discussion.14–19 After reviewing 100 patients older than 65 years who underwent elective spinal surgery, Rothrock et al18 concluded that cognitive recovery at 3 months after surgery was worse in frail patients. On the contrary, Charest-Morin et al19 concluded that frailty did not predict acute complications in 102 elderly patients (older than 65 years) who underwent simple lumbar spine surgery. Moreover, the existing literature does not address whether treating patients for frailty can affect complication rates in ASD or other spine surgery, even though several frailty indexes are modifiable. The present study was conducted to investigate relationships between treatment status for frailty and complications and outcomes of surgery for ASD.

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MATERIALS AND METHODS

Funding

No external funding was used for this study.

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Patient Population

This study was approved by our institution's review board. We retrospectively reviewed charts and radiographs for 240 consecutive patients with ASD who underwent corrective spine surgery at one of three academic hospitals. All patients were enrolled prospectively and analyzed retrospectively.

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Inclusion and Exclusion Criteria

To be eligible for this study, patients had to be at least 21 years old at the time of surgery, with a spinal deformity defined by a Cobb angle of 20° or more, C7 sagittal vertical axis (C7SVA) of 5 cm or more, or pelvic tilt of 25° or more. Patients had to have 5 or more fused vertebral levels, segmental pedicle screw fixation from the upper-instrumented vertebra to the lower instrumented vertebra (LIV), and complete 2-year follow-up data. Patients were excluded if they lacked appropriate radiographs or had a syndromic, neuromuscular, or other pathological condition.

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Data Collection and Assessment of Radiographs and Health-Related Quality of Life

We collected the following demographic and clinical data for each patient: age, sex, comorbidities (history of diabetes mellitus, cancer, congestive heart failure, hypertension requiring medication, cerebrovascular accident with or without neurological deficit, obstructive or other chronic pulmonary disease, conjunctive tissue disease, percutaneous coronary intervention, prior cardiac surgery, angina, transient ischemic attack, myocardial infarction, peripheral vascular disease, impaired sensorium, dementia, kidney disease, leukemia, lymphoma, liver disease, acquired immune deficiency syndrome or acquired immunodeficiency syndrome), body mass index, bone mineral density (BMD), and history of spine surgery. Frailty and comorbidities were assessed with the Modified Frailty Index (mFI) and Charlson Comorbidity Index (CCI).8,9,18,20–22 Patients were categorized as robust (mFI = 0), prefrail (mFI < 0.21), or frail (mFI > 0.21) based on their physical activity and comorbidities.

Surgical data collected for each patient included the Schwab-Scoliosis Research Society (SRS) ASD classification and subcategory,23 application of pedicle subtraction osteotomy, upper-instrumented vertebra and LIV levels, and number of fused vertebrae. BMD was calculated from dual-x ray absorptiometry scores of the right femoral neck. We used full-length standing whole-spine radiographs obtained at baseline and at the 6-week and 2-year follow-up appointments to determine the Cobb angle, C7SVA, T4-T12 thoracic kyphosis, T12-sacrum lumbar lordosis, sacral slope, pelvic tilt, pelvic incidence, T1 pelvic angle, and spinopelvic alignment (pelvic incidence −lumbar lordosis). As a health-related quality of life (HRQoL) surrogate, we used results from the Oswestry Disability Index and SRS-22r questionnaire (SRS-22r), obtained at baseline and at 2 years after surgery.

Of 249 candidates, 240 had complete demographic and radiographic data that would capture any postoperative complications. Seven patients were lost during follow-up and two patients died during follow-up for reasons unrelated to the surgery (cancer and unknown reason), and therefore were excluded from the analysis. Thus, the study included 240 patients (92% women; age 58.4 ± 16.7 years [22–79] years; mFI 0.07 ± 0.11 [0.00–0.64]; BMD T-score −1.0 ± 0.9 [−3.2–2.3], and 9.6 ± 2.8 [5–19] fused levels).

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Inclusion of Complications

We analyzed intraoperative and postoperative complications during the 2-year follow-up period based on patient charts and radiographic findings. Based on previous reports, surgical complications were categorized as neurological, implant-related (proximal and distal junctional kyphosis, rod breakage, pseudoarthrosis, implant dislodgement, screw breakage, and others), surgical-site infection, other infection (urinary tract infection and others), excessive bleeding (>2000 mL), delirium, cardiopulmonary (hemodynamic instability, myocardial infarction, deep venous thrombosis, pulmonary embolisms, thoracic atelectasis, congestive heart failure, and others), gastrointestinal (ileus, cholecystitis), or renal (acute renal failure).11,24 Complication severity was assessed by the Clavien–Dindo (C–D) classification.25

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Data Preparation and Evaluation of Frailty Status

Patients were categorized by frailty and treatment status as robust (R), frail or prefrail with good control (G), defined as a treatment regimen following the appropriate guidelines for each mFI factor (Supplemental Table 1, http://links.lww.com/BRS/B399), or poorly controlled frail or pre-frail (PC).26–31 Relationships between the treatment status for frailty and the development of complications were investigated by univariable and multivariable logistic regression analyses.

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Statistical Analysis

Differences between the R, G, and PC groups were compared by chi-square test, analysis of variance, or Tukey-honestly significant difference (HSD) test as appropriate. Changes between baseline and postoperative values were analyzed by paired t test. To compare the odds ratio (OR) of surgical complications between the R, G, and PC groups, we created a multivariable logistic regression model to evaluate age- and sex-adjusted associations and to predict the likelihood of developing surgical complications. A P value less than .05 with a confidence interval of 95% was considered statistically significant. Data were analyzed with the Statistical Package for the Social Sciences (SPSS statistics version 25.0, IBM Corp., Armonk, NY) and Stata14 (Stata Corporation, College Station, TX).

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RESULTS

Characteristics of the R, G, and P Groups

Patient characteristics are shown in Table 1. Of the 240 patients, 81 (34%) were categorized as prefrail and 17 (7%) as frail. Among the 98 frail or prefrail patients, frailty was under good control in 71 patients (72%, G group) and poor control in 27 patients (28%, PC group). Baseline values in the G and P groups were comparable for age, body mass index, dual-x ray absorptiometry (T-score), and Charlson Comorbidity Index; these values were significantly worse in the G and P groups than in the R group (Table 1). Time in surgery was similar in the G and PC groups but was significantly shorter in the R group (Table 1). However, the estimated blood loss was similar in the three groups.

TABLE 1

TABLE 1

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Comparison of Radiographic Parameters

The baseline sagittal-plane deformity was significantly worse in the G group than in the R group (Table 2). The postoperative C7SVA was worse in the G and PC groups than in the R group (Table 2). However, sagittal alignment was similar in the G and PC groups at the 2-year follow-up (Table 2).

TABLE 2

TABLE 2

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Comparison of Complications

Major complications developed in 107 of 240 patients (45%) within 2 years of ASD surgery; 54 (50%) occurred within 30 days of surgery (perioperative complications) and the remaining 53 (50%) occurred after 30 days but within 2 years. The rate of both perioperative and 2-year complications increased as the severity of frailty increased (Figure 1A and B). The perioperative complication rates and 2-year overall complication rates were similar in the G and PC groups but were significantly lower in the R group (Figure 1C and D). After adjusted the age and sex of these groups, OR for 2-year complications or perioperative complications were not different between G and PC group when referencing the G group (2-year complication; OR 1.26 [0.49–3.21]; P = 0.630, preoperative complication; OR 1.19 [0.46–3.11]; P = 0.717, Table 3). The incidence of C–D 2 or higher or C–D 3 or higher complication were both similar in the GC and PC groups (C–D >2, G 34% vs. PC 33%; C–D >3, G 25% vs. PC 19%) but were significantly lower than those in the R group (11% and 10% respectively; P < 0.01; Figures 2 and 3A and B). The adjusted OR for complications with a severity of C–D 2 or higher or C–D 3 or higher did not differ in the PC group (C–D >2, OR 0.98 [0.38–2.55], P = 0.970; C–D >3, OR 0.67 [0.22–2.07], P = 0.490). However, the OR for complications in the R group was significantly lower than in the GC group for any time period (Table 3).

Figure 1

Figure 1

TABLE 3

TABLE 3

Figure 2

Figure 2

Figure 3

Figure 3

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Clinical Outcomes in the R, G, and PC Groups

Regardless of the status of frailty treatment, clinical outcomes were similar in the G and PC groups at baseline and 2 years after surgery (Table 4). The SRS22 function and total scores were significantly lower in the G and PC groups than in the R group, both at baseline and 2 years after surgery (Table 4).

TABLE 4

TABLE 4

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DISCUSSION

Several demographic, radiographic, and surgical factors have been reported as risk factors for complications in ASD surgery.1–12 Relationships between HRQoL and comorbidities in adults with chronic conditions are widely recognized.7–12 Recent studies have described relationships between comorbidities and inferior clinical outcomes in ASD surgery.32 Typically, the presence of severe comorbidities (i.e., chronic obstructive pulmonary disease, severe cardiovascular disease, cerebrovascular disease with neurological deficit, etc.) influences HRQoL, as measured by various protocols and scales, in ASD surgery.11,32

Frailty is frequently observed clinically in older adults. Frailty increases the risk of poor health outcomes, including falls, incidence of disability, prolonged hospitalization, and mortality.13,14 Frailty is reported to be a significant risk factor for postsurgical complications and the need for extended care.7–10,14 Afilalo et al33 reported that frailty more than doubles the risk of morbidity and mortality in general surgery and under cardiovascular conditions. Recent studies have indicated that frailty increases the risk for perioperative complications after ASD surgery.7–10 Rothrock et al18 reported that frail patients are less likely than prefrail and robust patients to recover to cognitive baseline after elective spine surgery. Miller et al34 described associations between frailty and inferior clinical outcomes using many common quality and value metrics, including an increased risk of major complications. Yagi et al7 reported that mFI is an independent risk factor for 2-year complications in ASD surgery. After reviewing 1001 patients with ASD from the American College of Surgeons National Surgical Quality Improvement Program database, Leven et al11 reported that frailty is an independent predictor of postoperative complications, mortality, and reoperation in patients undergoing surgery for ASD.

It can be said that frailty is not simply the coexistence of many comorbidities, but is rather a state of increased vulnerability resulting from an aging-related decline in reserves and function. The mFI is currently the most common and most widely used method for measuring the severity of frailty, and most studies have used the mFI to determine predictors for adverse postoperative outcomes.7–12 However, the mFI is an index based primarily on the patient's medical history and activity and does not reflect the treatment status of each comorbidity. In the present study, we first investigated how the status of treatment for frailty affected the complication rates and clinical outcomes in ASD surgery. The clinical outcomes and complication rates were similar in the G and PC groups, which clearly indicated that even when prefrailty or frailty and its comorbidities are treated following the appropriate guidelines for each mFI factor, the clinical outcomes and complication rates for ASD surgery are not improved.

Possible explanations for the lack of association between treatment for frailty and complications and clinical outcomes in ASD surgery include the invasiveness of spinal surgery for ASD, which typically requires large dissection, long-segment spinal fusion, osteotomy, blood transfusion, and extended hospitalization. Thus, corrective surgery for ASD provides favorable outcomes but also poses a substantial risk for major complications and poor outcomes in both the perioperative and long-term postoperative periods.2,24,32 Yagi et al7 reported inferior clinical outcomes and higher complication rates for frail middle-aged and elderly patients who underwent surgery for ASD, whereas no difference was observed between robust, prefrail, and frail patients who underwent laminectomy, posterior lumbar interbody fusion for degenerative lumbar spondylolisthesis, or laminoplasty for cervical spondylotic myelopathy. Taken together, our findings indicate that frail patients may not fully recover after ASD or other highly invasive surgeries, even when frailty is treated according to the relevant guidelines for each mFI factor. It is also possible that associations between frailty and outcomes were confounded by differences in the degree of invasiveness between individual patients. Although indicators of surgical invasiveness (number of levels fused, time in surgery, and EB) were similar in the G and P groups, the complication rates might have been affected by variables that were not measured in this study.

This study was limited by its retrospective design, which precludes drawing firm conclusions about the effect of frailty treatment status on complications in ASD surgery. A prospective study by Smith et al32 reported higher complication rates for ASD surgery than those observed in the present study. However, we enrolled consecutive patients from a prospective database and analyzed the patients retrospectively, which is the most common method for investigating how a factor affects outcomes and complications in clinical research when randomized controlled trials are not possible. Our study is also limited by the lack of consensus criteria for treating frailty and prefrailty. In the present study, we evaluated treatment for frailty according to the appropriate guidelines for each mFI factor. However, treatment guidelines are evidence-based recommendations for clinicians caring for patients with specific conditions, and these guidelines aim to provide effective intervention for the specific condition rather than addressing how interventions might affect other conditions, surgical complications, HRQoL, and so forth. Therefore, it might be necessary to reconsider whether the specific comorbidity cut-off values offered in these guidelines are appropriate for analyzing associations between frailty treatment status and complications in ASD surgery.

Despite these limitations, the present study indicates that the status of treatment for frailty did not affect the risk of complications in ASD surgery. Careful patient selection and preoperative planning that takes patient frailty along with demographic and radiographic factors into account may decrease surgical complications and improve clinical outcomes for corrective surgery for ASD. Surgeons should routinely evaluate and consider frailty when contemplating surgical correction of ASD and when informing patients of possible complications.

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CONCLUSION

Our study demonstrated that treatment for frailty did not improve the risk of complications in surgery for ASD surgery. Frailty is a risk factor for inferior clinical outcomes and high rates of operative complications in ASD surgery regardless of whether the patient is being treated for frailty. Surgeons should routinely evaluate and consider frailty when contemplating surgical correction of ASD and when informing patients of possible complications.Key PointsA retrospective multicenter database review of 240 consecutive patients at least 21 years of age (range 58 ± 17) who underwent surgery for ASD and were followed at least 2 years.Patients were categorized as robust (R group), prefrail, or frail based on the mFI; prefrail and frail patients were divided by good control of frailty (G group), defined as treatment following the appropriate guidelines for each mFI factor, or poorly controlled frailty (PC group).The age- and sex-adjusted OR for 2-year complications was not different in the P group when the G group was referenced (OR 1.3 [0.5–3.2], P = 0.63).Regardless of its treatment status, frailty increases the risk of complications and inferior clinical outcomes in ASD surgery. Surgeons should routinely evaluate frailty and inform patients of frailty-related risks when considering surgery for ASD.

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References

1. Veeravagu A, Li A, Swinney C, et al. Predicting complication risk in spine surgery: a prospective analysis of a novel risk assessment tool. J Neurosurg Spine 2017; 27:81–91.
2. Ratliff JK, Balise R, Veeravagu A, et al. Predicting occurrence of spine surgery complications using “big data” modeling of an administrative claims database. J Bone Joint Surg Am 2016; 98:824–834.
3. Mirza SK, Deyo RA, Heagerty PJ, et al. Towards standardized measurement of adverse events in spine surgery: conceptual model and pilot evaluation. BMC Musculoskelet Disord 2006; 7:53.
4. Yagi M, King A, Boachie-Adjei O. Incidence, risk factors and classification of proximal junctional kyphosis: surgical outcomes review of adult idiopathic scoliosis. Spine (Phila Pa 1976) 2011; 36:E60–E68.
5. Yagi M, King AB, Boachie-Adjei O. Incidence, risk factors, and natural course of proximal junctional kyphosis: surgical outcomes review of adult idiopathic scoliosis. Minimum 5 years of follow-up. Spine (Phila Pa 1976) 2012; 37:1479–1489.
6. Yagi M, Rahm M, Gaines R, et al. Complex Spine Study Group. Characterization and surgical outcomes of proximal junctional failure (PJF) in surgically treated adult spine deformity patients. Spine (Phila Pa 1976) 2014; 39:E607–E614.
7. Yagi M, Fujita N, Okada E, et al. Impact of frailty and comorbidities on surgical outcomes and complications in adult spinal disorders. Spine (Phila Pa 1976) 2018; 43:1259–1267.
8. Flexman AM, Charest-Morin R, Stobart L, et al. Frailty and postoperative outcomes in patients undergoing surgery for degenerative spine disease. Spine J 2016; 16:1315–1323.
9. Ali R, Schwalb JM, Nerenz DR, et al. Use of the modified frailty index to predict 30-day morbidity and mortality from spine surgery. J Neurosurg Spine 2016; 25:537–541.
10. Adams P, Ghanem T, Stachler R, et al. Frailty as a predictor of morbidity and mortality in inpatient head and neck surgery. JAMA Otolaryngol Head Neck Surg 2013; 139:783–789.
11. Leven DM, Lee NJ, Kothari P, et al. Frailty index is a significant predictor of complications and mortality after surgery for adult spinal deformity. Spine (Phila Pa 1976) 2016; 41:E1394–E1401.
12. Karam J, Tsiouris A, Shepard A, et al. Simplified frailty index to predict adverse outcomes and mortality in vascular surgery patients. Ann Vasc Surg 2013; 27:904–908.
13. Parfentjev IA. Frailty of old age and bacterial allergy. Geriatrics 1956; 11:260–262.
14. Obeid NM, Azuh O, Reddy S, et al. Predictors of critical care-related complications in colectomy patients using the National Surgical Quality Improvement Program: exploring frailty and aggressive laparoscopic approaches. J Trauma Acute Care Surg 2012; 72:878–883.
15. Hewitt J, Moug SJ, Middleton M, et al. Prevalence of frailty and its association with mortality in general surgery. Am J Surg 2015; 209:254–259.
16. Abdullahi YS, Athanasopoulos LV, Casula RP, et al. Systematic review on the predictive ability of frailty assessment measures in cardiac surgery. Interact Cardiovasc Thorac Surg 2017; 24:619–624.
17. Eamer G, Gibson JA, Gillis C, et al. Surgical frailty assessment: a missed opportunity. BMC Anesthesiol 2017; 17:99.
18. Rothrock RJ, Steinberger JM, Badgery H, et al. Frailty status as a predictor of three month cognitive and functional recovery following spinal surgery: a prospective pilot study. Spine J 2018; pii: S1529-9430(18)30251-1.
19. Charest-Morin R, Street J, Zhang H. Frailty and sarcopenia do not predict adverse events in an elderly population undergoing non-complex primary elective surgery for degenerative conditions of the lumbar spine. Spine J 2018; 18:245–254.
20. Charlson ME, Pompei P, Ales KL, et al. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis 1987; 40:373–383.
21. Quan H, Li B, Couris CM, et al. Updating and validating the Charlson comorbidity index and score for risk adjustment in hospital discharge abstracts using data from 6 countries. Am J Epidemiol 2011; 173:676–682.
22. Ladha K, Zhao K, Quraishi SA, et al. The Deyo-Charlson and Elixhauser-van Walraven Comorbidity Indices as predictors of mortality in critically ill patients. BMJ Open 2015; 5:e008990.
23. Terran J, Schwab F, Shaffrey CI, et al. The SRS-Schwab adult spinal deformity classification: assessment and clinical correlations based on a prospective operative and nonoperative cohort. Neurosurgery 2013; 73:559–568.
24. Poorman GW, Passias PG, Buckland AJ, et al. Comparative analysis of peri-operative outcomes using nationally derived hospital discharge data relative to a prospective multi-center surgical database of adult spinal deformity surgery. Spine (Phila Pa 1976) 2017; 42:1165–1171.
25. Dindo D, Demartines N, Clavien PA. Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg 2004; 240:205–213.
26. Japan Diabetes Society. Treatment Guide for Diabetes 2016–2017 BUNKODO 2017, http://www.fa.kyorin.co.jp/jds/uploads/Treatment_Guide_for_Diabetes_2016-2017.pdf.
27. Shimamoto K, Ando K, Fujita T, et al. The Japanese Society of Hypertension Guidelines for the Management of Hypertension (JSH 2014). Hypertens Res 2014; 37:253–390.
28. Kitamura S. COPD guideline of Japanese Respiratory Society [in Japanese]. Nihon Rinsho 2003; 61:2077–2081.
29. JCS Joint Working Group. Guidelines for treatment of acute heart failure (JCS 2011). Circ J 2013; 77:2157–2201.
30. Shinohara Y. For readers (stroke specialists and general practitioners) of the Japanese guidelines for the management of stroke. Preface. J Stroke Cerebrovasc Dis 2011; 20 (4 suppl):S1–S6.
31. Miyata T, Akatsuka K, Akishita M, et al. Guidelines for the management of peripheral arterial occlusion disease (JCS 2015). Available at: http://www.j-circ.or.jp/guideline/pdf/JCS2015_miyata_h.pdf. Accessed April 1, 2018.
32. Smith JS, Shaffrey CI, Lafage V, et al. Comparison of best versus worst clinical outcomes for adult spinal deformity surgery: a retrospective review of a prospectively collected, multicenter database with 2-year follow-up. J Neurosurg Spine 2015; 23:349–359.
33. Afilalo J, Karunananthan S, Eisenberg MJ, et al. Role of frailty in patients with cardiovascular disease. Am J Cardiol 2009; 103:1616–1621.
34. Miller EK, Neuman BJ, Jain A, et al. An assessment of frailty as a tool for risk stratification in adult spinal deformity surgery. Neurosurg Focus 2017; 43:E3.
Keywords:

adult spinal deformity; complication; frailty; scoliosis

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