Does patient selection account for the perceived cost savings in outpatient spine surgery? A meta-analysis of current evidence and analysis from an administrative database

Presented at the 2018 AANS/CNS Joint Section on Disorders of the Spine and Peripheral Nerves

Restricted access

OBJECTIVE

From 1994 to 2006 outpatient spinal surgery increased 5-fold. The perceived cost savings with outcomes comparable to or better than those achieved with inpatient admission for the same procedures are desirable in an era where health expenditures are scrutinized. The increase in outpatient spine surgery is also driven by the proliferation of ambulatory surgery centers. In this study, the authors hypothesized that the total savings in outpatient spine surgery is largely driven by patient selection and biases toward healthier patients.

METHODS

A meta-analysis assessed patient selection factors and outcomes associated with outpatient spine procedures. Pooled odds ratios and mean differences were calculated using a Bayesian random-effects model. The authors extended this analysis in a novel way by using the results of the meta-analysis to examine cost data from an administrative database of academically affiliated hospitals. A Bayesian approach with priors informed by the meta-analysis was used to compare costs for inpatient and outpatient performance of anterior cervical discectomy and fusion (ACDF) and lumbar laminectomy.

RESULTS

Sixteen studies with a total of 370,195 patients met the inclusion criteria. Outpatient procedures were associated with younger patient age (mean difference [MD] −2.34, 95% credible interval [CrI] −4.39 to −0.34) and no diabetes diagnosis (odds ratio [OR] 0.78, 95% CrI 0.54–0.97). Outpatient procedures were associated with a lower likelihood of reoperation (OR 0.42, 95% CrI 0.16–0.80), 30-day readmission (OR 0.39, 95% CrI 0.16–0.74), and complications (OR 0.29, 95% CrI 0.15–0.50) and with lower overall costs (MD −$121,392.72, 95% CrI −$216,824.81 to −$23,632.92). Additional analysis of the national administrative data revealed more modest cost savings than those found in the meta-analysis for outpatient spine surgeries relative to inpatient spine surgeries. Estimated cost savings for both younger patients ($555 for those age 30–35 years [95% CrI −$733 to −$374]) and older patients ($7290 for those age 65–70 years [95% CrI −$7380 to −$7190]) were less than the overall cost savings found in the meta-analysis.

CONCLUSIONS

Compared to inpatient spine surgery, outpatient spine surgery was associated with better short-term outcomes and an initial reduction in direct costs. A selection bias for outpatient procedures toward younger, healthier patients may confound these results. The additional analysis of the national database suggests that cost savings in the outpatient setting may be less than previously reported and a result of outpatient procedures being offered more frequently to younger and healthier individuals.

ABBREVIATIONS ACDF = anterior cervical discectomy and fusion; BMI = body mass index; CCI = Charlson Comorbidity Index; CDB/RM = (Vizient) Clinical Data Base/Resource Manager; CrI = credible interval; DM = diabetes mellitus; LOS = length of stay; MD = mean difference; OR = odds ratio.

Article Information

Correspondence Mohamad Bydon: Mayo Clinic, Rochester, MN. bydon.mohamad@mayo.edu.

INCLUDE WHEN CITING Published online September 14, 2018; DOI: 10.3171/2018.4.SPINE1864.

Disclosures Dr. Nassr reports support for the study described from Pfizer and Premia Spine and fellowship support from AOSpine.

© AANS, except where prohibited by US copyright law.

Headings

Figures

  • View in gallery

    Study selection flowchart.

  • View in gallery

    Forest plot for age as a factor for patient selection between inpatient and outpatient spine surgery.

  • View in gallery

    Forest plot for effect of diabetes on spine surgery setting.

  • View in gallery

    Forest plot for comparison of reoperation rates between inpatient and outpatient spine surgery.

  • View in gallery

    Forest plot for comparison of 30-day readmission rates between inpatient and outpatient spine surgery.

  • View in gallery

    Forest plot for comparison of complication rates between inpatient and outpatient spine surgery.

  • View in gallery

    Forest plot for comparison of costs between inpatient and outpatient spine surgery.

References

  • 1

    Adamson TGodil SSMehrlich MMendenhall SAsher ALMcGirt MJ: Anterior cervical discectomy and fusion in the outpatient ambulatory surgery setting compared with the inpatient hospital setting: analysis of 1000 consecutive cases. J Neurosurg Spine 24:8788842016

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 2

    Ahn JMassel DHMayo BCHijji FYNarain ASAboushaala K: The utility of routinely obtaining postoperative laboratory studies following a minimally invasive transforaminal lumbar interbody fusion. Clin Spine Surg 30:E1405E14102017

    • Search Google Scholar
    • Export Citation
  • 3

    Baird EOBrietzke SCWeinberg ADMcAnany SJQureshi SACho SK: Ambulatory spine surgery: a survey study. Global Spine J 4:1571602014

  • 4

    Baird EOEgorova NNMcAnany SJQureshi SAHecht ACCho SK: National trends in outpatient surgical treatment of degenerative cervical spine disease. Global Spine J 4:1431502014

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 5

    Baser O: Too much ado about propensity score models? Comparing methods of propensity score matching. Value Health 9:3773852006

  • 6

    Bekelis KMissios SKakoulides GRahmani RSimmons N: Selection of patients for ambulatory lumbar discectomy: results from four US states. Spine J 14:194419502014

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 7

    Best MJBuller LTEismont FJ: National trends in ambulatory surgery for intervertebral disc disorders and spinal stenosis: a 12-year analysis of the National Surveys of Ambulatory Surgery. Spine (Phila Pa 1976) 40:170317112015

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 8

    Best NMSasso RC: Outpatient lumbar spine decompression in 233 patients 65 years of age or older. Spine (Phila Pa 1976) 32:113511402007

  • 9

    Chin KRPencle FJRCoombs AVBrown MDConklin KJO’Neill AM: Lateral lumbar interbody fusion in ambulatory surgery centers: patient selection and outcome measures compared with an inhospital cohort. Spine (Phila Pa 1976) 41:6866922016

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 10

    Crawford DCLi CSSprague SBhandari M: Clinical and cost implications of inpatient versus outpatient orthopedic surgeries: a systematic review of the published literature. Orthop Rev (Pavia) 7:61772015

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 11

    Hozo SPDjulbegovic BHozo I: Estimating the mean and variance from the median, range, and the size of a sample. BMC Med Res Methodol 5:132005

  • 12

    Kruschke JK: Bayesian estimation supersedes the t test. J Exp Psychol Gen 142:5736032013

  • 13

    Lee MJKalfas IHolmer HSkelly A: Outpatient surgery in the cervical spine: is it safe? Evid Based Spine Care J 5:1011112014

  • 14

    Liu JTBriner RPFriedman JA: Comparison of inpatient vs. outpatient anterior cervical discectomy and fusion: a retrospective case series. BMC Surg 9:32009

  • 15

    Martin CTPugely AJGao YMendoza-Lattes S: Thirty-day morbidity after single-level anterior cervical discectomy and fusion: identification of risk factors and emphasis on the safety of outpatient procedures. J Bone Joint Surg Am 96:128812942014

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 16

    McClelland S IIIOren JHProtopsaltis TSPassias PG: Outpatient anterior cervical discectomy and fusion: A meta-analysis. J Clin Neurosci 34:1661682016

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 17

    McGirt MJGodil SSAsher ALParker SLDevin CJ: Quality analysis of anterior cervical discectomy and fusion in the outpatient versus inpatient setting: analysis of 7288 patients from the NSQIP database. Neurosurg Focus 39(6):E92015

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 18

    Missios SRahmani RBekelis K: Spinal cord stimulators: socioeconomic disparities in four US states. Neuromodulation 17:4514562014

  • 19

    Ortega ASarmiento JMPatil CMukherjee DUgiliweneza BNuño M: Comparative analysis of inpatient and outpatient interspinous process device placement for lumbar spinal stenosis. J Neurol Surg A Cent Eur Neurosurg 76:4434502015

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 20

    Peikes DNMoreno LOrzol SM: Propensity score matching. A note of caution for evaluators of social programs. Am Stat 62:2222312008

  • 21

    Pugely AJMartin CTGao YMendoza-Lattes SA: Outpatient surgery reduces short-term complications in lumbar discectomy: an analysis of 4310 patients from the ACS-NSQIP database. Spine (Phila Pa 1976) 38:2642712013

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 22

    Samuel AMGrauer JNRihn JALabrum JT IV: Two-level anterior cervical discectomy and fusion: an outpatient surgery? J Spinal Disord Tech 28:3493512015

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 23

    Silvers HRLewis PJSuddaby LSAsch HLClabeaux DEBlumenson LE: Day surgery for cervical microdiscectomy: is it safe and effective? J Spinal Disord 9:2872931996

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 24

    Smith WDWohns RNWChristian GRodgers EJRodgers WB: Outpatient minimally invasive lumbar interbody: fusion predictive factors and clinical results. Spine (Phila Pa 1976) 41 (Suppl 8):S106S1222016

    • Search Google Scholar
    • Export Citation
  • 25

    Stieber JRBrown KDonald GDCohen JD: Anterior cervical decompression and fusion with plate fixation as an outpatient procedure. Spine J 5:5035072005

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 26

    Sutton AJAbrams KR: Bayesian methods in meta-analysis and evidence synthesis. Stat Methods Med Res 10:2773032001

  • 27

    Walid MSRobinson JS IIIRobinson ERMBrannick BBAjjan MRobinson JS Jr: Comparison of outpatient and inpatient spine surgery patients with regards to obesity, comorbidities and readmission for infection. J Clin Neurosci 17:149714982010

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 28

    Wohns RN: A comparison of the safety of lumbar fusions performed as outpatient (<25-hour discharge) or inpatient (>24-hour discharge) procedures. Spine J 12 (9 Suppl):S155S1562012 (Abstract)

    • Search Google Scholar
    • Export Citation

TrendMD

Metrics

Metrics

All Time Past Year Past 30 Days
Abstract Views 200 200 12
Full Text Views 129 129 9
PDF Downloads 152 152 9
EPUB Downloads 0 0 0

PubMed

Google Scholar