Determining the quality and effectiveness of surgical spine care: patient satisfaction is not a valid proxy

Background contextGiven the unsustainable costs of the US health-care system, health-care purchasers, payers, and hospital systems are adopting the concept of value-based purchasing by shifting care away from low-quality providers or hospitals. Legislation now allows public reporting of these quality rankings. True measures of quality, such as surgical morbidity and validated questionnaires of effectiveness, are burdensome and costly to collect. Hence, patients' satisfaction with care has emerged as a commonly used metric as a proxy for quality because of its feasibility of collection. However, patient satisfaction metrics have yet to be validated as a measure of overall quality of surgical spine care.PurposeWe set out to determine whether patient satisfaction is a valid measure of safety and effectiveness of care in a prospective longitudinal spine registry.Study designProspective longitudinal cohort study.Patient populationAll patients undergoing elective spine surgery for degenerative conditions over a 6-month period at a single medical center.Outcome measuresPatient-reported outcome instruments (numeric rating scale [NRS], Oswestry disability index [ODI], neck disability index [NDI], short-form 12-item survey [SF-12], Euro-Qol-5D [EQ-5D], Zung depression scale, and Modified Somatic Perception Questionnaire [MSPQ] anxiety scale), return to work, patient satisfaction with outcome, and patient satisfaction with provider care.MethodsAll patients undergoing elective spine surgery for degenerative conditions over a 6-month period at a single medical center were enrolled into a prospective longitudinal registry. Data collected on all patients included demographics, disease characteristics, treatment variables, readmissions/reoperations, and all 90-day surgical morbidity. Patient-reported outcome instruments (NRS, ODI, NDI, SF-12, EQ-5D, Zung depression scale, and MSPQ anxiety scale), return to work, patient satisfaction with outcome, and patient satisfaction with provider care were recorded at baseline and 3 months after treatment. Receiver-operating characteristic (ROC) curve analysis was performed to determine whether extent of improvement in quality of life (SF-12 physical component summary [PCS]) and disability (ODI/NDI) accurately predicted patient satisfaction versus dissatisfaction. Standard interpretation of area under the curve (AUC) was used: less than 0.7, poor; 0.7 to 0.8, fair; and greater than 0.8, good accuracy. Multivariate logistic regression analysis was performed to determine if surgical morbidity (quality) or improvement in disability and quality of life (effectiveness of care) were independently associated with patient satisfaction.ResultsFour hundred twenty-two (84%) patients completed all questionnaires 3 months after surgery during the reviewed time period (mean age 55±14 years). Lumbar surgery was performed in 287 (68%) and cervical surgery in 135 (32%) patients. There were 51 (12.1%) 90-day complications, including 21 (5.0%) readmissions and 12 (2.8%) return to operating room. Three hundred fifty-eight (84.8%) patients were satisfied with provider care and 288 (68.2%) with their outcome. Satisfaction with provider care: In ROC analyses, extent of improvement in quality of life (SF-12) and disability (ODI/NDI) differentiated satisfaction versus dissatisfaction with care with very poor accuracy (AUC 0.49–0.69). In regression analysis, 3-month morbidity (odds ratio [95% confidence interval]: 1.45 [0.79–2.66]), readmission (0.66 [0.24–1.80]), improvement in quality of life (SF-12 PCS), or improvement in general health (health transition index) were not associated with satisfaction with care. Satisfaction with outcome: In ROC analyses, improvement in quality of life (SF-12) and disability (ODI/NDI) failed to differentiate satisfaction with good accuracy (AUC 0.76). Neither 90-day morbidity (1.05 [0.46–2.34]) nor 90-day readmission (0.27 [0.04–2.04]) was associated with satisfaction with outcome in regression analysis.ConclusionsPatient satisfaction is not a valid measure of overall quality or effectiveness of surgical spine care. Patient satisfaction metrics likely represent the patient's subjective contentment with health-care service, a distinct aspect of care. Satisfaction metrics are important patient-centered measures of health-care service but should not be used as a proxy for overall quality, safety, or effectiveness of surgical spine care.     

Incidence of Low Back Pain After Lumbar Discectomy for Herniated Disc and Its Effect on Patient-reported Outcomes

Background

Long-term postdiscectomy degenerative disc disease and low back pain is a well-recognized disorder; however, its patient-centered characterization and quantification are lacking.

Questions/purposes

We performed a systematic literature review and prospective longitudinal study to determine the frequency of recurrent back pain after discectomy and quantify its effect on patient-reported outcomes (PROs).

Methods

A MEDLINE search was performed to identify studies reporting on the frequency of recurrent back pain, same-level recurrent disc herniation, and reoperation after primary lumbar discectomy. After excluding studies that did not report the percentage of patients with persistent back or leg pain more than 6 months after discectomy or did not report the rate of same level recurrent herniation, 90 studies, which in aggregate had evaluated 21,180 patients, were included in the systematic review portion of this study. For the longitudinal study, all patients undergoing primary lumbar discectomy between October 2010 and March 2013 were enrolled into our prospective spine registry. One hundred fifteen patients were more than 12 months out from surgery, 103 (90%) of whom were available for 1-year outcomes assessment. PROs were prospectively assessed at baseline, 3 months, 1 year, and 2 years. The threshold of deterioration used to classify recurrent back pain was the minimum clinically important difference in back pain (Numeric Rating Scale Back Pain [NRS-BP]) or Disability (Oswestry Disability Index [ODI]), which were 2.5 of 10 points and 20 of 100 points, respectively.

Results Systematic Review

The proportion of patients reporting short-term (6–24 months) and long-term (> 24 months) recurrent back pain ranged from 3% to 34% and 5% to 36%, respectively. The 2-year incidence of recurrent disc herniation ranged from 0% to 23% and the frequency of reoperation ranged from 0% to 13%.

Prospective Study

At 1-year and 2-year followup, 22% and 26% patients reported worsening of low back pain (NRS: 5.3 ± 2.5 versus 2.7 ± 2.8, p < 0.001) or disability (ODI%: 32 ± 18 versus 21 ± 18, p < 0.001) compared with 3 months.

Conclusions

In a systematic literature review and prospective outcomes study, the frequency of same-level disc herniation requiring reoperation was 6%. Two-year recurrent low back pain may occur in 15% to 25% of patients depending on the level of recurrent pain considered clinically important, and this leads to worse PROs at 1 and 2 years postoperatively.     

Accurately measuring the quality and effectiveness of lumbar surgery in registry efforts: determining the most valid and responsive instruments

Background contextProspective registries have emerged as a feasible way to capture real-world care across large patient populations. However, the proven validity of more robust and cumbersome patient-reported outcomes instruments (PROis) must be balanced with what is feasible to apply in large-scale registry efforts.PurposeTo determine the relative validity and responsiveness of common PROis in accurately determining effectiveness of lumbar fusion for degenerative lumbar spondylolisthesis in registry efforts.Study designProspective cohort study.Patient sampleFifty-eight patients undergoing transforaminal lumbar interbody fusion (TLIF) for degenerative lumbar spondylolisthesisOutcome measuresPatient-reported outcome measures for pain (numeric rating scale for back and leg pain [NRS-BP, NRS-LP]), disability (Oswestry Disability Index [ODI]), general health (Short Form [SF]-12), quality of life (QOL) (EuroQol five dimensions [EQ-5D]), and depression (Zung depression scale [ZDS]) were assessed.MethodsFifty-eight patients undergoing primary TLIF for lumbar spondylolisthesis were entered into an institutional registry and prospectively followed for 2 years. Baseline and 2-year patient-reported outcomes were assessed. To assess the validity of PROis to discriminate between effective and noneffective improvements, receiver operating characteristic curves were generated for each outcomes instrument. An area under the curve (AUC) of ≥0.80 was considered an accurate discriminator. The difference between standardized response means (SRMs) in patients reporting meaningful improvement versus not was calculated to determine the relative responsiveness of each instrument.ResultsFor pain and disability, ODI had AUC=0.94, suggesting it as an accurate discriminator of meaningful improvement. Oswestry Disability Index was most responsive to postoperative improvement (SRM difference: 2.18), followed by NRS-BP and NRS-LP. For general health and QOL, SF-12 physical component score (AUC: 0.90), ZDS (AUC: 0.89), and SF-12 mental component score (AUC: 0.85) were all accurate discriminators of meaningful improvement, however, EQ-5D was most accurate (AUC: 0.97). EuroQol five dimensions was also most responsive (SRM difference: 2.83).ConclusionsFor pain and disability, ODI was the most valid and responsive measure of effectiveness of lumbar fusion. Numeric rating scale-BP and NRS-LP should not be used as substitutes for ODI in measuring effectiveness of care in registry efforts. For health-related QOL, EQ-5D was the most valid and responsive measure of improvement, however, SF-12 and ZDS are valid alternatives with less responsiveness.     

Differential modulation of beta2 and beta4 subunits of human neuronal nicotinic acetylcholine receptors by acidification

We have shown previously that acidification increases the affinity of agonists to rat alpha3beta4 nicotinic acetylcholine receptors (nAChR) and accelerates both the activation and decay kinetics of agonist-induced currents recorded from human embryonic kidney 293 cells stably expressing the receptor (Abdrakhmanova et al., 2002b). Here, we report on experiments examining the effect of rapid acidification on four different subtypes (alpha3beta4alpha5, alpha4beta2, alpha3beta2, and alpha3beta2alpha5) of human neuronal nAChRs stably expressed in tsA201 cells using a piezoelectric device for rapid (<5 ms) solution application. Application of ACh, at its EC(50) concentration for each nAChR subtype, at pH values 7.4 and 6.0, showed that acidification, similarly to that reported for rat alpha3beta4 acetylcholine receptors (AChRs), increased the amplitude and accelerated the activation and decay kinetics of the currents in human alpha3beta4alpha5 AChRs by increasing their affinity to the agonist. In sharp contrast, acidification reduced the amplitude but accelerated the decay kinetics of the current in all human beta2-containing nAChR subtypes (alpha3beta2, alpha3alpha5beta2, alpha4beta2) examined in this study. Brief application of ACh at saturating concentration (1 mM) on alpha3beta4alpha5 AChRs induced a "rebound current" upon rapid washout of the agonist at pH 7.4, but no "rebound current" was observed in alpha3beta2 AChRs. Surprisingly, acidification, pH 6.0, applied only during the agonist pulse also accelerated the decay kinetics of the "rebound current". Our data provide evidence for the specificity of proton-induced modulation of neuronal nAChRs based on their beta subunit composition. Furthermore, in alpha3beta4alpha5 AChR, we find that protonation effects may persist, after washout of acidic solutions, consistent with proton-induced conformational changes of the receptor.     

The serologic diagnosis of group B salmonelloses]

Antibacterial sera activities towards Citrobacter O22 and Salmonella typhimurium were tested with O22, O1, O4, O5, O12 erythrocytic diagnostic agents. Cross activities of O22, O1, O4, O5, O12, and Hi antigens were tested with the same and Hi erythrocytic diagnostic agents in the antibody neutralization test. The findings have confirmed the identity or very close relationship between the tested O antigens. Screening for antigens of the excretions from patients with S. typhimurium and Citrobacter O22 infections has shown that indication of Hi antigen may be considered as the differentiating criterion between these infections.     

In vitro and in vivo characterization of a novel negative allosteric modulator of neuronal nAChRs

In this study, we compared the in vitro and in vivo neuronal nicotinic acetylcholine receptor (nAChR) properties of 1,2,3,3a,4,8b-hexahydro-2-benzyl-6-N,N-dimethylamino-1-methylindeno[1,2,-b]pyrrole (HDMP, 4) to that of negative allosteric modulator (NAM), PCP. Patch-clamp experiments showed that HDMP exhibited an inhibitory functional activity at α7 nAChRs with an IC₅₀ of 0.07 μM, and was 357- and 414-fold less potent at α4β2 and α3β4 nAChRs, with IC₅₀s of 25.1 and 29.0 μM, respectively. Control patch-clamp experiments showed that PCP inhibited α7, α4β2 and α3β4 nAChRs with IC₅₀s of to 1.3, 29.0 and 6.4 μM, respectively. Further, HDMP did not exhibit any appreciable binding affinity to either α7 or α4β2 nAChRs, suggesting its action via a non-competitive mechanism at these neuronal nAChR subtypes. The in vivo study showed that HDMP was a potent antagonist of nicotine-induced analgesia in the tail-flick (AD₅₀ = 0.008 mg/kg), but not in the hot-plate test. All together, our in vitro and in vivo data suggest that HDMP is a novel NAM of neuronal nAChRs with potent inhibitory activity at α7 nAChR subtype at concentrations ≤1 μM that are not effective for α4β2 and α3β4 nAChRs.