Modeled cost-effectiveness of transforaminal lumbar interbody fusion compared with posterolateral fusion for spondylolisthesis using N2QOD data

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OBJECTIVE

Transforaminal lumbar interbody fusion (TLIF) has become the most commonly used fusion technique for lumbar degenerative disorders. This suggests an expectation of better clinical outcomes with this technique, but this has not been validated consistently. How surgical variables and choice of health utility measures drive the cost-effectiveness of TLIF relative to posterolateral fusion (PSF) has not been established. The authors used health utility values derived from Short Form-6D (SF-6D) and EQ-5D and different cost-effectiveness thresholds to evaluate the relative cost-effectiveness of TLIF compared with PSF.

METHODS

From the National Neurosurgery Quality and Outcomes Database (N2QOD), 101 patients with spondylolisthesis who underwent PSF were propensity matched to patients who underwent TLIF. Health-related quality of life measures and perioperative parameters were compared. Because health utility values derived from the SF-6D and EQ-5D questionnaires have been shown to vary in patients with low-back pain, quality-adjusted life years (QALYs) were derived from both measures. On the basis of these matched cases, a sensitivity analysis for the relative cost per QALY of TLIF versus PSF was performed in a series of cost-assumption models.

RESULTS

Operative time, blood loss, hospital stay, and 30-day and 90-day readmission rates were similar for the TLIF and PSF groups. Both TLIF and PSF significantly improved back and leg pain, Oswestry Disability Index (ODI) scores, and EQ-5D and SF-6D scores at 3 and 12 months postoperatively. At 12 months postoperatively, patients who had undergone TLIF had greater improvements in mean ODI scores (30.4 vs 21.1, p = 0.001) and mean SF-6D scores (0.16 vs 0.11, p = 0.001) but similar improvements in mean EQ-5D scores (0.25 vs 0.22, p = 0.415) as patients treated with PSF. At a cost per QALY threshold of $100,000 and using SF-6D–based QALYs, the authors found that TLIF would be cost-prohibitive compared with PSF at a surgical cost of $4830 above that of PSF. However, with EQ-5D–based QALYs, TLIF would become cost-prohibitive at an increased surgical cost of $2960 relative to that of PSF. With the 2014 US per capita gross domestic product of $53,042 as a more stringent cost-effectiveness threshold, TLIF would become cost-prohibitive at surgical costs $2562 above that of PSF with SF-6D–based QALYs or at a surgical cost exceeding that of PSF by $1570 with EQ-5D–derived QALYs.

CONCLUSIONS

As with all cost-effectiveness studies, cost per QALY depended on the measure of health utility selected, durability of the intervention, readmission rates, and the accuracy of the cost assumptions.

ABBREVIATIONSN2QOD = National Neurosurgery Quality and Outcomes Database; ODI = Oswestry Disability Index; PSF = posterolateral fusion; QALY = quality-adjusted life year; TLIF = transforaminal lumbar interbody fusion.

OBJECTIVE

Transforaminal lumbar interbody fusion (TLIF) has become the most commonly used fusion technique for lumbar degenerative disorders. This suggests an expectation of better clinical outcomes with this technique, but this has not been validated consistently. How surgical variables and choice of health utility measures drive the cost-effectiveness of TLIF relative to posterolateral fusion (PSF) has not been established. The authors used health utility values derived from Short Form-6D (SF-6D) and EQ-5D and different cost-effectiveness thresholds to evaluate the relative cost-effectiveness of TLIF compared with PSF.

METHODS

From the National Neurosurgery Quality and Outcomes Database (N2QOD), 101 patients with spondylolisthesis who underwent PSF were propensity matched to patients who underwent TLIF. Health-related quality of life measures and perioperative parameters were compared. Because health utility values derived from the SF-6D and EQ-5D questionnaires have been shown to vary in patients with low-back pain, quality-adjusted life years (QALYs) were derived from both measures. On the basis of these matched cases, a sensitivity analysis for the relative cost per QALY of TLIF versus PSF was performed in a series of cost-assumption models.

RESULTS

Operative time, blood loss, hospital stay, and 30-day and 90-day readmission rates were similar for the TLIF and PSF groups. Both TLIF and PSF significantly improved back and leg pain, Oswestry Disability Index (ODI) scores, and EQ-5D and SF-6D scores at 3 and 12 months postoperatively. At 12 months postoperatively, patients who had undergone TLIF had greater improvements in mean ODI scores (30.4 vs 21.1, p = 0.001) and mean SF-6D scores (0.16 vs 0.11, p = 0.001) but similar improvements in mean EQ-5D scores (0.25 vs 0.22, p = 0.415) as patients treated with PSF. At a cost per QALY threshold of $100,000 and using SF-6D–based QALYs, the authors found that TLIF would be cost-prohibitive compared with PSF at a surgical cost of $4830 above that of PSF. However, with EQ-5D–based QALYs, TLIF would become cost-prohibitive at an increased surgical cost of $2960 relative to that of PSF. With the 2014 US per capita gross domestic product of $53,042 as a more stringent cost-effectiveness threshold, TLIF would become cost-prohibitive at surgical costs $2562 above that of PSF with SF-6D–based QALYs or at a surgical cost exceeding that of PSF by $1570 with EQ-5D–derived QALYs.

CONCLUSIONS

As with all cost-effectiveness studies, cost per QALY depended on the measure of health utility selected, durability of the intervention, readmission rates, and the accuracy of the cost assumptions.

The primary goal of lumbar fusion surgery is to improve a patient's quality of life by adequately decompressing the neural structures and achieving a stable arthrodesis. However, the optimal surgical approach to treating degenerative conditions of the lumbar spine remains controversial. Although historically posterolateral spinal fusion (PSF) was the most commonly used procedure, transforaminal lumbar interbody fusion (TLIF) is increasingly becoming more common.29 Theoretical advantages of TLIF over PSF include anterior column support, indirect foraminal decompression, removal of the disc as a pain generator, and restoration of lumbar lordosis.3,10,18,30,36 These theoretical advantages, which come at an increased cost, have not consistently translated into better clinical outcomes.1,12,19–21,40 A recent study conducting a cost-utility analysis of data from a prospective randomized trial20 reported that TLIF was not a relevant alternative to PSF from a socioeconomic, societal perspective.8

Determination of the cost-effectiveness of any intervention requires measures of both the cost and the effectiveness of the intervention. For an intervention to be more cost-effective than another, it either has to cost less and be at least as effective, or has to generate sufficient added value to justify the additional cost. Although a current procedural terminology code for PSF as a standalone procedure is still being used, the American Medical Association in 2012 bundled the codes for TLIF and PSF into a single posterior interbody fusion code (https://www.cms.gov/Medicare/Medicare-Fee-for-Service-Payment/PhysicianFeeSched/PFS-Federal-Regulation-Notices-Items/CMS1253669.html). This change will reduce both the relative value and the payment rate for this new single current procedural terminology code as compared with the payment rates for the 2 previous codes used to report the procedures. However, because of the additional implant cost and the additional time required to insert an interbody device, TLIF will likely cost more.

The other half of the cost-effectiveness equation is measuring an intervention's effectiveness. Health gains or losses after an intervention are measured as quality-adjusted life years (QALYs),11,17 which take into account both the quantity and the quality of life. The QALY is the arithmetic product of life expectancy and a measure of the quality of the remaining life years. Several generic preference-weighted health state classification questionnaires, which combine a health-status measure with a societal value or utility for each health state,4 are used in economic studies. The most widely used questionnaires are the EQ-5D13 and the Short Form–6D (SF-6D).5,6 However, several studies have shown that although both the EQ-5D and SF-6D are psychometrically valid measures of health state utility in patients with low-back pain, they cannot be used interchangeably.22,24,25,32,33 Differences in the health state utility values derived from the EQ-5D and SF-6D are substantial enough that several cost-effectiveness studies present their results using both the EQ-5D and the SF-6D as part of the sensitivity analysis.34,35

The purpose of this study was to determine for patients with spondylolisthesis enrolled in the National Neurosurgery Quality and Outcomes Database (N2QOD)2,26,27 at what threshold of increased surgical cost TLIF will be come cost-prohibitive relative to PSF when both EQ-5D and SF-6D health state utility values are considered.

Methods

In October 2014, the N2QOD database was queried to retrieve the records of those patients who had a diagnosis of spondylolisthesis, a 1-level or 2-level posterior lumbar fusion with or without an interbody graft, and complete baseline and 12-month follow-up data. Only patients with spondylolisthesis were included in this study, as the definition for this pathology is widely accepted, and surgical fusion is considered an effective treatment for this condition. As per the N2QOD registry inclusion criteria, only patients with vertebral slips of Meyerding28 Grade I or lower and who had not previously undergone surgery were included. Delineation between isthmic and degenerative types of spondylolisthesis was not available. Patients who had a concurrent or subsequent anterior procedure, such as an anterior lumbar interbody fusion, or a lateral access procedure, such as an extreme-lateral interbody fusion or direct lateral interbody fusion, were excluded. Patients who underwent a noninstrumented fusion or a greater than 2-level fusion were also excluded.

To control for an individual surgeon selection bias that is inherent in surgical decision making, patients who had undergone PSF were propensity matched to patients who had undergone TLIF; the patients were matched on the following variables: age, sex, body mass index, smoking status, race, educational level, employment status, presence of an anxiety disorder, insurance status, workers' compensation status, symptom duration, American Society of Anesthesiologists grade, number of levels fused, preoperative back and leg pain numeric rating scales (ranging from 0 to 10)23 and Oswestry Disability Index (ODI)14,15 and EQ-5D13 scores. The propensity matching allows for matching multiple patient characteristics across groups without one-on-one matching of each case to a control.9,31 As none of the short forms (36-Item Short Form Health Survey [SF-36] or Short Form–12)37 are collected as part of the N2QOD registry, the SF-6D scores were estimated from the ODI scores with a previously published logistic regression model.7

Statistical analysis was carried out with IBM SPSS software version 21.0. To account for multiple concurrent analyses, statistical significance was set at the p < 0.01 level for both the propensity-matching analysis and subsequent comparisons. Student's t-test was used to determine any statistical significance of differences between continuous demographic variables and to compare preoperative and postoperative health-related quality of life scores of the PSF group with those of the TLIF groups. The Fisher exact test was used to compare categorical variables of the 2 groups.

Results

The search of the N2QOD database identified 2035 patients who underwent lumbar fusion between the inception of the registry in March 2012 and October 2013. For 1722 of these patients (84.6%), 12-month follow-up data were available. This cohort included 771 patients (44.8%) with spondylolisthesis, of whom 134 (17.4%) underwent PSF and 637 (82.6%) TLIF. After the propensity matching, 101 cases from each group were included in the analysis.

As expected after propensity matching, the TLIF and PSF cohorts were similar in demographic, health status, and health insurance data (Table 1). Operative time and blood loss, hospital length of stay, and 30-day and 90-day readmission rates were also similar for the 2 groups (Table 2). Both TLIF and PSF improved the scores for back and leg pain, ODI, EQ-5D, and SF-6D at 3 and 12 months after surgery relative to baseline. Twelve months after surgery, patients who had undergone TLIF had a statistically significantly greater improvement in the mean ODI score than the PSF patients (30.4 vs 21.1, p = 0.001). The TLIF patients also had greater improvements in the mean scores for back pain (4.2 vs 3.5, p = 0.090) and leg pain (4.6 vs 3.7, p = 0.096) than those in the PSF group, but these differences did not reach statistical significance. Both groups had similar gains in the EQ-5D utility scores (mean 0.25 vs 0.22, p = 0.415). However, gains in the SF-6D utility scores were statistically significantly greater for the TLIF group than for the PSF group (0.16 vs 0.11, p = 0.001) (Table 3).

TABLE 1.

Summary of the demographic, health status, and health insurance data of the patients in this study*

VariableTreatmentp Value
TLIF (n = 101)PSF (n = 101)
Mean age in yrs (SD)63.3 (11.1)65.3 (9.5)0.186
Male42320.189
Mean BMI (SD)31.9 (7.0)31.3 (6.3)0.581
Smoking0.623
  Current every-day smoker128
  Current some-days smoker11
  Former smoker3631
  Never a smoker5158
  Unknown13
Race0.540
  White9497
  Native American10
  African American54
  Asian10
Education0.244
  < High school58
  High school3540
  2-yr college1925
  4-yr college2418
  Postgraduate1810
Employment status0.187
  Employed, currently working3225
  Employed, not currently working73
  Unemployed6273
Anxiety disorder14110.670
Insurance status0.535
  Uninsured01
  Medicare4750
  Medicaid41
  VA/government23
  Private4846
Workers' compensation0.194
  No9995
  Yes23
  Unknown03

BMI = body mass index; VA = Department of Veterans Affairs.

Data represent number of patients, unless indicated otherwise.

TABLE 2.

Summary of surgical and discharge data*

VariableTreatment (SD)p Value
TLIFPSF
ASA grade0.106
  113
  25137
  34958
  403
No. of levels0.132
  17463
  22738
Mean EBL in ml381.5 (361.8)418.7 (295.1)0.484
Mean op time in mins199.0 (91.2)194.2 (93.0)0.711
LOS in days3.74 (2.3)4.0 (7.6)0.646
Discharge disposition0.955
  Home routine7168
  Home w/health service1111
  Postacute care setting1618
  Transfer to acute care34
Readmission
  w/in 30 days020.498
  w/in 3 mos140.369

ASA = American Society of Anesthesiologists; EBL = estimated blood loss; LOS = length of stay.

Data represent number of patients, unless indicated otherwise.

TABLE 3.

Summary of surgical outcomes data*

ScoreTreatmentp Value
TLIFPSF
Back pain
  Baseline7.1 (2.2)7.3 (2.4)0.444
  3 mos4.3 (2.9)3.9 (3.0)0.332
  12 mos4.2 (3.1)3.5 (3.2)0.090
Leg pain
  Baseline6.8 (3.1)6.8 (3.0)1.000
  3 mos4.9 (3.9)4.4 (4.1)0.426
  12 mos4.6 (3.9)3.7 (3.8)0.096
ODI
  Baseline53.6 (15.8)52.7 (17.4)0.685
  3 mos25.3 (16.8)19.8 (19.0)0.034
  12 mos30.4 (18.6)21.1 (19.2)0.001
EQ-5D
  Baseline0.51 (0.22)0.51 (0.22)0.976
  3 mos0.24 (0.25)0.25 (0.29)0.760
  12 mos0.25 (0.26)0.22 (0.25)0.415
SF-6D
  Baseline0.51 (0.08)0.51 (0.09)0.685
  3 mos0.13 (0.09)0.10 (0.10)0.034
  12 mos0.16 (0.10)0.11 (0.10)0.001

Data represent mean scores (SD).

Both EQ-5D and SF-56D utility values indicated that TLIF gave greater gains in QALYs than PSF. However, according to the EQ-5D utility values, the QALY gain with TLIF relative to PSF was 0.03; in contrast, for the SF-6D utility values, the QALY gain with TLIF relative to PSF was 0.05. Thus, at a cost-effectiveness threshold of $100,000,38 TLIF would be cost-prohibitive at surgical costs exceeding those of PSF by more than $4830 ($100,000 × 0.04830) according to the SF-6D–based QALYs. However, on the basis of EQ-5D–based QALYs, TLIF would become cost-prohibitive when its surgical costs exceeded those of PSF by $2960 ($100,000 × 0.0296). When we used the 2014 US per capita gross domestic product of $53,042 (from http://data.worldbank.org/indicator/NY.GDP.PCAP.CD) as a more stringent cost-effectiveness threshold,39 TLIF became cost-prohibitive at surgical costs exceeding those of PSF by $2562 ($53,042 × 0.0483) according to the SF-6D–based QALYs or at a surgical costs greater exceeding those of PSF by $1570 ($53,042 × 0.0296) according to the EQ-5D–derived QALYs.

Discussion

The N2QOD is prospective multicenter, multisurgeon quality assurance program with a substantial infrastructure to optimize data integrity and validity.2,26,27 Although patient enrollment is based on widely accepted, well-defined etiologic diagnostic criteria, surgical treatment is determined by the standard practice of the individual surgeon. The use of a large registry allows researchers to pragmatically evaluate surgical interventions for a specific diagnostic indication.

Reflective of the increasing use of interbody support with posterior fusions,29 most spondylolisthesis patients in the current study (83%) underwent TLIF, and only 17% PSF. This trend in use of these 2 treatments has been widely observed despite the lack of strong evidence supporting the routine use of TLIF.

Although previous studies1,16,20 have shown that TLIF results in longer operative times and greater estimated blood loss than PSF, the current study showed no difference in these surgical parameters between the 2 treatment groups. This lack of a difference may be due to increased surgical proficiency, improvement in surgical techniques and tools, inclusion of only 1-level and 2-level fusions in the present study, and variability in surgical skill. Previous studies have also reported higher complication rates with TLIF,19,21,30 but these were not observed in the current study. In addition, the length of stay, discharge disposition, and 30-day and 90-day readmission rates were also similar for the 2 groups. The observed similarities in perioperative parameters and complication and readmission rates suggested no substantial difference in direct costs between the 2 treatments, except for the interbody implant and graft material.

Patients in the TLIF group had substantially better ODI scores at 3 and 12 months after surgery than those in the PSF group. However, the TLIF and PSF groups had similar improvements in back and leg pain scores. These inconsistencies may be explained by the unidimensional property of the pain scores, which may limit their sensitivity to change, in contrast to the ODI score, which is multidimensional.

Greater health utility gains were observed in the TLIF group than in the PSF group, but these gains were greater when the SF-6D rather than the EQ-5D questionnaire was used. The EQ-5D score is less sensitive to change than that of the SF-6D for patients with low-back disorders.22,24,25,32,33 These differences in health utility valuation for the same disease entity in the same cohort have prompted researchers to present the results of cost-effectiveness analyses for both valuation methods. Several studies have shown that whereas the SF-6D and ODI scores are dispersed and normally distributed, the EQ-5D scores tend to cluster and to have a bimodal distribution.6,33 The EQ-5D score has also been shown to have a ceiling effect in patients with low-back pain.6,24,25,33 In addition, the EQ-5D currently in wide use has 3 choices for each domain and may therefore not be sensitive enough to detect small changes in health status.

Depending on which cost-effectiveness threshold and health utility value were used, the increased surgical cost at which TLIF becomes less cost-effective than PSF varied from $1570 to $4830. The use of more expensive bone graft substitutes or enhancers in PSF or TLIF can change this cost-per-QALY ratio. However, the N2QOD registry does not have sufficient granularity to allow analysis of this issue.

There are limitations to this study, some of which are inherent to the use of registry data. Isthmic and degenerative spondylolisthesis types were not delineated in the present study. Information about the proportion of TLIF patients in our cohort who underwent a minimally invasive approach was also not available. The relatively small sample size in the present study may have caused a failure to detect statistically significant differences, especially in the ordinal values of back and leg pain scores. The relatively short length of follow-up precluded any study on the relative durability of TLIF and PSF. Although the SF-6D should ideally be derived from either the Short Form-12 or the SF-36,4,5 neither of these 2 forms was administered as part of the N2QOD. Thus, the SF-6D transformed from the ODI was used.7 Of note, previous studies have shown no statistically significant difference between the SF-6D score estimated from the ODI and the SF-36–derived SF-6D score in a cohort of patients who underwent lumbar fusion surgery for degenerative conditions.7

Conclusions

Using a large national spine registry, we showed here that operative time, length of hospital stay, complication rates, discharge disposition, and readmission rates were similar for both TLIF and PSF. QALY gains with TLIF calculated with the SF-6D were greater than those calculated with EQ-5D, and these gains may justify the additional costs associated with TLIF compared with PSF. Importantly, this study demonstrates that the cost per QALY depends on the measure of health utility selected, durability of the intervention, readmission rates, and the accuracy of the cost assumptions.

References

  • 1

    Abdu WALurie JDSpratt KFTosteson ANAZhao WTosteson TD: Degenerative spondylolisthesis: does fusion method influence outcome? Four-year results of the spine patient outcomes research trial. Spine (Phila Pa 1976) 34:235123602009

    • Search Google Scholar
    • Export Citation
  • 2

    Asher ALSperoff TDittus RSParker SLDavies JMSelden N: The National Neurosurgery Quality and Outcomes Database (N2QOD): a collaborative North American outcomes registry to advance value-based spine care. Spine (Phila Pa 1976) 39:22 Suppl 1S106S1162014

    • Search Google Scholar
    • Export Citation
  • 3

    Audat ZMoutasem OYousef KMohammad B: Comparison of clinical and radiological results of posterolateral fusion, posterior lumbar interbody fusion and transforaminal lumbar interbody fusion techniques in the treatment of degenerative lumbar spine. Singapore Med J 53:1831872012

    • Search Google Scholar
    • Export Citation
  • 4

    Brazier JDeverill MGreen C: A review of the use of health status measures in economic evaluation. J Health Serv Res Policy 4:1741841999

    • Search Google Scholar
    • Export Citation
  • 5

    Brazier JRoberts JDeverill M: The estimation of a preference-based measure of health from the SF-36. J Health Econ 21:2712922002

    • Search Google Scholar
    • Export Citation
  • 6

    Brazier JRoberts JTsuchiya ABusschbach J: A comparison of the EQ-5D and SF-6D across seven patient groups. Health Econ 13:8738842004

    • Search Google Scholar
    • Export Citation
  • 7

    Carreon LYGlassman SDMcDonough CMRampersaud RBerven SShainline M: Predicting SF-6D utility scores from the Oswestry disability index and numeric rating scales for back and leg pain. Spine (Phila Pa 1976) 34:208520892009

    • Search Google Scholar
    • Export Citation
  • 8

    Christensen AHøy KBünger CHelmig PHansen ESAndersen T: Transforaminal lumbar interbody fusion vs posterolateral instrumented fusion: cost-utility evaluation along side an RCT with a 2-year follow-up. Eur Spine J 23:113711432014

    • Search Google Scholar
    • Export Citation
  • 9

    D'Agostino RB Jr: Propensity score methods for bias reduction in the comparison of a treatment to a non-randomized control group. Stat Med 17:226522811998

    • Search Google Scholar
    • Export Citation
  • 10

    Dehoux EFourati EMadi KReddy BSegal P: Posterolateral versus interbody fusion in isthmic spondylolisthesis: functional results in 52 cases with a minimum follow-up of 6 years. Acta Orthop Belg 70:5785822004

    • Search Google Scholar
    • Export Citation
  • 11

    Drummond MFSculpher MJTorrance GWO'Brien BJStoddart GL: Methods for the Economic Evaluation of Health Care Programmes New YorkOxford University Press2005

    • Search Google Scholar
    • Export Citation
  • 12

    Ekman PMöller HTullberg TNeumann PHedlund R: Posterior lumbar interbody fusion versus posterolateral fusion in adult isthmic spondylolisthesis. Spine (Phila Pa 1976) 32:217821832007

    • Search Google Scholar
    • Export Citation
  • 13

    EuroQol Group: EuroQol—a new facility for the measurement of health-related quality of life. Health Policy 16:1992081990

  • 14

    Fairbank JCCouper JDavies JBO'Brien JP: The Oswestry low back pain disability questionnaire. Physiotherapy 66:2712731980

  • 15

    Fairbank JCPynsent PB: The Oswestry Disability Index. Spine (Phila Pa 1976) 25:294029522000

  • 16

    Farrokhi MRRahmanian AMasoudi MS: Posterolateral versus posterior interbody fusion in isthmic spondylolisthesis. J Neurotrauma 29:156715732012

    • Search Google Scholar
    • Export Citation
  • 17

    Gold MRSiegel JERussel LBWeinstein MC: Cost-Effectiveness in Health and Medicine OxfordOxford University Press1996

  • 18

    Ha KYNa KHShin JHKim KW: Comparison of posterolateral fusion with and without additional posterior lumbar interbody fusion for degenerative lumbar spondylolisthesis. J Spinal Disord Tech 21:2292342008

    • Search Google Scholar
    • Export Citation
  • 19

    Hee HTCastro FP JrMajd MEHolt RTMyers L: Anterior/posterior lumbar fusion versus transforaminal lumbar interbody fusion: analysis of complications and predictive factors. J Spinal Disord 14:5335402001

    • Search Google Scholar
    • Export Citation
  • 20

    Høy KBünger CNiederman BHelmig PHansen ESLi HS: Transforaminal lumbar interbody fusion (TLIF) versus posterior instrumented fusion (PLF) in degenerative lumbar disorders: A randomized clinical trial with 2-year follow-up. Eur Spine J 22:202220292013

    • Search Google Scholar
    • Export Citation
  • 21

    Humphreys SCHodges SDPatwardhan AGEck JCMurphy RBCovington LA: Comparison of posterior and transforaminal approaches to lumbar interbody fusion. Spine (Phila Pa 1976) 26:5675712001

    • Search Google Scholar
    • Export Citation
  • 22

    Kind PDolan PGudex CWilliams A: Variations in population health status: results from a United Kingdom national questionnaire survey. BMJ 316:7367411998

    • Search Google Scholar
    • Export Citation
  • 23

    McCaffery MBeebe A: Pain: A Clinical Manual for Nursing Practice BaltimoreMosby1993

  • 24

    McDonough CMGrove MRTosteson TDLurie JDHilibrand ASTosteson AN: Comparison of EQ-5D, HUI, and SF-36-derived societal health state values among spine patient outcomes research trial (SPORT) participants. Qual Life Res 14:132113322005

    • Search Google Scholar
    • Export Citation
  • 25

    McDonough CMTosteson TDTosteson ANJette AMGrove MRWeinstein JN: A longitudinal comparison of 5 preference-weighted health state classification systems in persons with intervertebral disk herniation. Med Decis Making 31:2702802011

    • Search Google Scholar
    • Export Citation
  • 26

    McGirt MJParker SLAsher ALNorvell DSherry NDevin CJ: Role of prospective registries in defining the value and effectiveness of spine care. Spine (Phila Pa 1976) 39:22 Suppl 1S117S1282014

    • Search Google Scholar
    • Export Citation
  • 27

    McGirt MJSperoff TDittus RSHarrell FE JrAsher AL: The National Neurosurgery Quality and Outcomes Database (N2QOD): general overview and pilot-year project description. Neurosurg Focus 34:1E62013

    • Search Google Scholar
    • Export Citation
  • 28

    Meyerding HW: Spondylolisthesis. Surg Gynecol Obstet 54:3713771931

  • 29

    Pannell WCSavin DDScott TPWang JCDaubs MD: Trends in the surgical treatment of lumbar spine disease in the United States. Spine J 15:171917272015

    • Search Google Scholar
    • Export Citation
  • 30

    Potter BKFreedman BAVerwiebe EGHall JMPolly DW JrKuklo TR: Transforaminal lumbar interbody fusion: clinical and radiographic results and complications in 100 consecutive patients. J Spinal Disord Tech 18:3373462005

    • Search Google Scholar
    • Export Citation
  • 31

    Rosenbaum PR: Model-based direct adjustment. J Am Stat Assoc 82:3873941987

  • 32

    Sach THBarton GRJenkinson CDoherty MAvery AJMuir KR: Comparing cost-utility estimates: does the choice of EQ-5D or SF-6D matter?. Med Care 47:8898942009

    • Search Google Scholar
    • Export Citation
  • 33

    Søgaard RChristensen FBVidebaek TSBünger CChristiansen T: Interchangeability of the EQ-5D and the SF-6D in long-lasting low back pain. Value Health 12:6066122009

    • Search Google Scholar
    • Export Citation
  • 34

    Tosteson ANLurie JDTosteson TDSkinner JSHerkowitz HAlbert T: Surgical treatment of spinal stenosis with and without degenerative spondylolisthesis: cost-effectiveness after 2 years. Ann Intern Med 149:8458532008

    • Search Google Scholar
    • Export Citation
  • 35

    Tosteson ANSkinner JSTosteson TDLurie JDAndersson GBBerven S: The cost effectiveness of surgical versus nonoperative treatment for lumbar disc herniation over two years: evidence from the Spine Patient Outcomes Research Trial (SPORT). Spine (Phila Pa 1976) 33:210821152008

    • Search Google Scholar
    • Export Citation
  • 36

    Wang YPFei QQiu GXZhao HZhang JGTian Y: Outcome of posterolateral fusion versus circumferential fusion with cage for lumbar stenosis and low degree lumbar spondylolisthesis. Chin Med Sci J 21:41472006

    • Search Google Scholar
    • Export Citation
  • 37

    Ware JE JrSherbourne CD: The MOS 36-Item Short Form Health Survey (SF-36). I Conceptual framework and item selection. Med Care 30:4734831992

    • Search Google Scholar
    • Export Citation
  • 38

    Winkelmayer WCWeinstein MCMittleman MAGlynn RJPliskin JS: Health economic evaluations: the special case of end-stage renal disease treatment. Med Decis Making 22:4174302002

    • Search Google Scholar
    • Export Citation
  • 39

    World Health Organization: Macroeconomics and Health: Investing in Health for Economic Development: Report of the Commission on Macroeconomics and Health GenevaWorld Health Organization2001

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  • 40

    Zhou ZJZhao FDFang XQZhao XFan SW: Meta-analysis of instrumented posterior interbody fusion versus instrumented posterolateral fusion in the lumbar spine. J Neurosurg Spine 15:2953102011

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Disclosures

Dr. Glassman is employed by Norton Healthcare, holds patents with Medtronic, has received clinical or research support not related to this study from Norton Healthcare, and has received royalties from Medtronic. Dr. Carreon is employed by Norton Healthcare; has received clinical or research support not related to this study from Norton Healthcare, AO Spine, OREF, and SRS; has received travel funds from OREF, DOD, the Association for Collaborative Spine Research, Center for Spine Surgery and Research of the University of Southern Denmark, and the University of Louisville Institutional Review Board; and has received honoraria for participation in review panels at the National Institutes of Health, Children's Tumor Foundation, and the Global Evidence Advisory Board, Medtronic. Dr. Mummaneni is a consultant for DePuy Spine, has direct stock ownership in Spinicity/ISD, and receives royalties from DePuy Spine and from the publishers Taylor and Francis, Thieme, and Springer.

Author Contributions

Conception and design: Carreon, Glassman. Acquisition of data: all authors. Analysis and interpretation of data: Carreon. Drafting the article: Carreon. Critically revising the article: Carreon, Glassman, Ghogawala, Mummaneni. Reviewed submitted version of manuscript: Carreon, Glassman, Ghogawala, Mummaneni. Approved the final version of the manuscript on behalf of all authors: Carreon. Statistical analysis: Carreon. Administrative/technical/material support: McGirt, Asher.

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Article Information

INCLUDE WHEN CITING Published online February 19, 2016; DOI: 10.3171/2015.10.SPINE15917.

Correspondence Leah Y. Carreon, Norton Leatherman Spine Center, 210 E. Gray St., Ste. 900, Louisville, KY 40202. email: leah.carreon@nortonhealthcare.org.

© AANS, except where prohibited by US copyright law.

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References

  • 1

    Abdu WALurie JDSpratt KFTosteson ANAZhao WTosteson TD: Degenerative spondylolisthesis: does fusion method influence outcome? Four-year results of the spine patient outcomes research trial. Spine (Phila Pa 1976) 34:235123602009

    • Search Google Scholar
    • Export Citation
  • 2

    Asher ALSperoff TDittus RSParker SLDavies JMSelden N: The National Neurosurgery Quality and Outcomes Database (N2QOD): a collaborative North American outcomes registry to advance value-based spine care. Spine (Phila Pa 1976) 39:22 Suppl 1S106S1162014

    • Search Google Scholar
    • Export Citation
  • 3

    Audat ZMoutasem OYousef KMohammad B: Comparison of clinical and radiological results of posterolateral fusion, posterior lumbar interbody fusion and transforaminal lumbar interbody fusion techniques in the treatment of degenerative lumbar spine. Singapore Med J 53:1831872012

    • Search Google Scholar
    • Export Citation
  • 4

    Brazier JDeverill MGreen C: A review of the use of health status measures in economic evaluation. J Health Serv Res Policy 4:1741841999

    • Search Google Scholar
    • Export Citation
  • 5

    Brazier JRoberts JDeverill M: The estimation of a preference-based measure of health from the SF-36. J Health Econ 21:2712922002

    • Search Google Scholar
    • Export Citation
  • 6

    Brazier JRoberts JTsuchiya ABusschbach J: A comparison of the EQ-5D and SF-6D across seven patient groups. Health Econ 13:8738842004

    • Search Google Scholar
    • Export Citation
  • 7

    Carreon LYGlassman SDMcDonough CMRampersaud RBerven SShainline M: Predicting SF-6D utility scores from the Oswestry disability index and numeric rating scales for back and leg pain. Spine (Phila Pa 1976) 34:208520892009

    • Search Google Scholar
    • Export Citation
  • 8

    Christensen AHøy KBünger CHelmig PHansen ESAndersen T: Transforaminal lumbar interbody fusion vs posterolateral instrumented fusion: cost-utility evaluation along side an RCT with a 2-year follow-up. Eur Spine J 23:113711432014

    • Search Google Scholar
    • Export Citation
  • 9

    D'Agostino RB Jr: Propensity score methods for bias reduction in the comparison of a treatment to a non-randomized control group. Stat Med 17:226522811998

    • Search Google Scholar
    • Export Citation
  • 10

    Dehoux EFourati EMadi KReddy BSegal P: Posterolateral versus interbody fusion in isthmic spondylolisthesis: functional results in 52 cases with a minimum follow-up of 6 years. Acta Orthop Belg 70:5785822004

    • Search Google Scholar
    • Export Citation
  • 11

    Drummond MFSculpher MJTorrance GWO'Brien BJStoddart GL: Methods for the Economic Evaluation of Health Care Programmes New YorkOxford University Press2005

    • Search Google Scholar
    • Export Citation
  • 12

    Ekman PMöller HTullberg TNeumann PHedlund R: Posterior lumbar interbody fusion versus posterolateral fusion in adult isthmic spondylolisthesis. Spine (Phila Pa 1976) 32:217821832007

    • Search Google Scholar
    • Export Citation
  • 13

    EuroQol Group: EuroQol—a new facility for the measurement of health-related quality of life. Health Policy 16:1992081990

  • 14

    Fairbank JCCouper JDavies JBO'Brien JP: The Oswestry low back pain disability questionnaire. Physiotherapy 66:2712731980

  • 15

    Fairbank JCPynsent PB: The Oswestry Disability Index. Spine (Phila Pa 1976) 25:294029522000

  • 16

    Farrokhi MRRahmanian AMasoudi MS: Posterolateral versus posterior interbody fusion in isthmic spondylolisthesis. J Neurotrauma 29:156715732012

    • Search Google Scholar
    • Export Citation
  • 17

    Gold MRSiegel JERussel LBWeinstein MC: Cost-Effectiveness in Health and Medicine OxfordOxford University Press1996

  • 18

    Ha KYNa KHShin JHKim KW: Comparison of posterolateral fusion with and without additional posterior lumbar interbody fusion for degenerative lumbar spondylolisthesis. J Spinal Disord Tech 21:2292342008

    • Search Google Scholar
    • Export Citation
  • 19

    Hee HTCastro FP JrMajd MEHolt RTMyers L: Anterior/posterior lumbar fusion versus transforaminal lumbar interbody fusion: analysis of complications and predictive factors. J Spinal Disord 14:5335402001

    • Search Google Scholar
    • Export Citation
  • 20

    Høy KBünger CNiederman BHelmig PHansen ESLi HS: Transforaminal lumbar interbody fusion (TLIF) versus posterior instrumented fusion (PLF) in degenerative lumbar disorders: A randomized clinical trial with 2-year follow-up. Eur Spine J 22:202220292013

    • Search Google Scholar
    • Export Citation
  • 21

    Humphreys SCHodges SDPatwardhan AGEck JCMurphy RBCovington LA: Comparison of posterior and transforaminal approaches to lumbar interbody fusion. Spine (Phila Pa 1976) 26:5675712001

    • Search Google Scholar
    • Export Citation
  • 22

    Kind PDolan PGudex CWilliams A: Variations in population health status: results from a United Kingdom national questionnaire survey. BMJ 316:7367411998

    • Search Google Scholar
    • Export Citation
  • 23

    McCaffery MBeebe A: Pain: A Clinical Manual for Nursing Practice BaltimoreMosby1993

  • 24

    McDonough CMGrove MRTosteson TDLurie JDHilibrand ASTosteson AN: Comparison of EQ-5D, HUI, and SF-36-derived societal health state values among spine patient outcomes research trial (SPORT) participants. Qual Life Res 14:132113322005

    • Search Google Scholar
    • Export Citation
  • 25

    McDonough CMTosteson TDTosteson ANJette AMGrove MRWeinstein JN: A longitudinal comparison of 5 preference-weighted health state classification systems in persons with intervertebral disk herniation. Med Decis Making 31:2702802011

    • Search Google Scholar
    • Export Citation
  • 26

    McGirt MJParker SLAsher ALNorvell DSherry NDevin CJ: Role of prospective registries in defining the value and effectiveness of spine care. Spine (Phila Pa 1976) 39:22 Suppl 1S117S1282014

    • Search Google Scholar
    • Export Citation
  • 27

    McGirt MJSperoff TDittus RSHarrell FE JrAsher AL: The National Neurosurgery Quality and Outcomes Database (N2QOD): general overview and pilot-year project description. Neurosurg Focus 34:1E62013

    • Search Google Scholar
    • Export Citation
  • 28

    Meyerding HW: Spondylolisthesis. Surg Gynecol Obstet 54:3713771931

  • 29

    Pannell WCSavin DDScott TPWang JCDaubs MD: Trends in the surgical treatment of lumbar spine disease in the United States. Spine J 15:171917272015

    • Search Google Scholar
    • Export Citation
  • 30

    Potter BKFreedman BAVerwiebe EGHall JMPolly DW JrKuklo TR: Transforaminal lumbar interbody fusion: clinical and radiographic results and complications in 100 consecutive patients. J Spinal Disord Tech 18:3373462005

    • Search Google Scholar
    • Export Citation
  • 31

    Rosenbaum PR: Model-based direct adjustment. J Am Stat Assoc 82:3873941987

  • 32

    Sach THBarton GRJenkinson CDoherty MAvery AJMuir KR: Comparing cost-utility estimates: does the choice of EQ-5D or SF-6D matter?. Med Care 47:8898942009

    • Search Google Scholar
    • Export Citation
  • 33

    Søgaard RChristensen FBVidebaek TSBünger CChristiansen T: Interchangeability of the EQ-5D and the SF-6D in long-lasting low back pain. Value Health 12:6066122009

    • Search Google Scholar
    • Export Citation
  • 34

    Tosteson ANLurie JDTosteson TDSkinner JSHerkowitz HAlbert T: Surgical treatment of spinal stenosis with and without degenerative spondylolisthesis: cost-effectiveness after 2 years. Ann Intern Med 149:8458532008

    • Search Google Scholar
    • Export Citation
  • 35

    Tosteson ANSkinner JSTosteson TDLurie JDAndersson GBBerven S: The cost effectiveness of surgical versus nonoperative treatment for lumbar disc herniation over two years: evidence from the Spine Patient Outcomes Research Trial (SPORT). Spine (Phila Pa 1976) 33:210821152008

    • Search Google Scholar
    • Export Citation
  • 36

    Wang YPFei QQiu GXZhao HZhang JGTian Y: Outcome of posterolateral fusion versus circumferential fusion with cage for lumbar stenosis and low degree lumbar spondylolisthesis. Chin Med Sci J 21:41472006

    • Search Google Scholar
    • Export Citation
  • 37

    Ware JE JrSherbourne CD: The MOS 36-Item Short Form Health Survey (SF-36). I Conceptual framework and item selection. Med Care 30:4734831992

    • Search Google Scholar
    • Export Citation
  • 38

    Winkelmayer WCWeinstein MCMittleman MAGlynn RJPliskin JS: Health economic evaluations: the special case of end-stage renal disease treatment. Med Decis Making 22:4174302002

    • Search Google Scholar
    • Export Citation
  • 39

    World Health Organization: Macroeconomics and Health: Investing in Health for Economic Development: Report of the Commission on Macroeconomics and Health GenevaWorld Health Organization2001

    • Search Google Scholar
    • Export Citation
  • 40

    Zhou ZJZhao FDFang XQZhao XFan SW: Meta-analysis of instrumented posterior interbody fusion versus instrumented posterolateral fusion in the lumbar spine. J Neurosurg Spine 15:2953102011

    • Search Google Scholar
    • Export Citation

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