Economic analysis of two-stage septic revision after total hip arthroplasty: What are the relevant costs for the hospital's orthopedic department?

BACKGROUND: The number of septic total hip arthroplasty (THA) revisions is increasing continuously, placing a growing financial burden on hospitals. Orthopedic departments performing septic THA revisions have no basis for decision making regarding resource allocation as the costs of this procedure for the departments are unknown. It is widely assumed that septic THA procedures can only be performed at a loss for the department. Therefore, the purpose of this study was to investigate whether this assumption is true by performing a detailed analysis of the costs and revenues for two-stage septic THA revision. METHODS: Patients who underwent revision THA for septic loosening in two sessions from January 2009 through March 2012 were included in this retrospective, consecutive cost study from the orthopedic department's point of view. We analyzed variable and case-fixed costs for septic revision THA with special regard to implantation and explantation stay. By using marginal costing approach we neglected hospital-fixed costs. Outcome measures include reimbursement and daily contribution margins. RESULTS: The average direct costs (reimbursement) incurred for septic two-stage revision THA was €10,828 (€24,201). The difference in cost and contribution margins per day was significant (p < .001 and p = 0.019) for ex- and implantation (€4147 vs. €6680 and €429 vs. €306) while length of stay and reimbursement were comparable. CONCLUSIONS: This is the first detailed analysis of the hospital department's cost for septic revision THA performed in two sessions. Disregarding hospital-fixed costs the included variable and case fixed-costs were covered by revenues. This study provides cost data, which will be guidance for health care decision makers.

A workplace exercise versus health promotion intervention to prevent and reduce the economic and personal burden of non-specific neck pain in office personnel: protocol of a cluster-randomised controlled trial.

INTRODUCTION: Non-specific neck pain is a major burden to industry, yet the impact of introducing a workplace ergonomics and exercise intervention on work productivity and severity of neck pain in a population of office personnel is unknown. RESEARCH QUESTION: Does a combined workplace-based best practice ergonomic and neck exercise program reduce productivity losses and risk of developing neck pain in asymptomatic workers, or decrease severity of neck pain in symptomatic workers, compared to a best practice ergonomic and general health promotion program? DESIGN: Prospective cluster randomised controlled trial. PARTICIPANTS AND SETTING: Office personnel aged over 18 years, and who work>30 hours/week. INTERVENTION: Individualised best practice ergonomic intervention plus 3×20 minute weekly, progressive neck/shoulder girdle exercise group sessions for 12 weeks. CONTROL: Individualised best practice ergonomic intervention plus 1-hour weekly health information sessions for 12 weeks. MEASUREMENTS: Primary (productivity loss) and secondary (neck pain and disability, muscle performance, and quality of life) outcome measures will be collected using validated scales at baseline, immediate post-intervention and 12 months after commencement. PROCEDURE: 640 volunteering office personnel will be randomly allocated to either an intervention or control arm in work group clusters. ANALYSIS: Analysis will be on an 'intent-to-treat' basis and per protocol. Multilevel, generalised linear models will be used to examine the effect of the intervention on reducing the productivity loss in dollar units (AUD), and severity of neck pain and disability. DISCUSSION: The findings of this study will have a direct impact on policies that underpin the prevention and management of neck pain in office personnel.

A conceptual model of compensation/decompensation in lumbar segmental instability.

Lumbar spinal instability (LSI) is a common spinal disorder and can be associated with substantial disability. The concept of defining clinically relevant classifications of disease or 'target condition' is used in diagnostic research. Applying this concept to LSI we hypothesize that a set of clinical and radiological criteria can be developed to identify patients with this target condition who are at high risk of 'irreversible' decompensated LSI for whom surgery becomes the treatment of choice. In LSI, structural deterioration of the lumbar disc initiates a degenerative cascade of segmental instability. Over time, radiographic signs become visible: traction spurs, facet joint degeneration, misalignment, stenosis, olisthesis and de novo scoliosis. Ligaments, joint capsules, local and distant musculature are the functional elements of the lumbar motion segment. Influenced by non-functional factors, these functional elements allow a compensation of degeneration of the motion segment. Compensation may happen on each step of the degenerative cascade but cannot reverse it. However, compensation of LSI may lead to an alleviation or resolution of clinical symptoms. In return, the target condition of decompensation of LSI may cause the new occurrence of symptoms and pain. Functional compensation and decompensation are subject to numerous factors that can change which makes estimation of an individual's long-term prognosis difficult. Compensation and decompensation may influence radiographic signs of degeneration, e.g. the degree of misalignment and segmental angulation caused by LSI is influenced by the tonus of the local musculature. This conceptual model of compensation/decompensation may help solve the debate on functional and psychosocial factors that influence low back pain and to establish a new definition of non-specific low back pain. Individual differences of identical structural disorders could be explained by compensated or decompensated LSI leading to changes in clinical symptoms and pain. Future spine surgery will have to carefully define and measure functional aspects of LSI, e.g. to identify a point of no return where multidisciplinary interventions do not allow a re-compensation and surgery becomes the treatment of choice.

Comparison of pain-resilient working individuals to population-based case controls with/without momentary low back pain.

BACKGROUND: Few studies have examined the 20% of individuals who never experience an episode of low back pain (LBP). To date, no investigation has been undertaken that examines a group who claim to have never experienced LBP in their lifetime in comparison to two population-based case-control groups with and without momentary LBP. This study investigates whether LBP-resilient workers between 50 and 65 years had better general health, demonstrated more positive health behaviour and were better able to achieve routine activities compared with both case-control groups. METHODS: Forty-two LBP-resilient participants completed the same pain assessment questionnaire as a population-based LBP sample from a nationwide, large-scale cross-sectional survey in Switzerland. The LBP-resilient participants were pairwise compared to the propensity score-matched case controls by exploring differences in demographic and work characteristics, and by calculating odds ratios (ORs) and effect sizes. A discriminant analysis explored group differences, while the multiple logistic regression analysis specified single indicators which accounted for group differences. RESULTS: LBP-resilient participants were healthier than the case controls with momentary LBP and achieved routine activities more easily. Compared to controls without momentary LBP, LBP-resilient participants had a higher vitality, a lower workload, a healthier attitude towards health and behaved more healthily by drinking less alcohol. CONCLUSIONS: By demonstrating a difference between LBP-resilient participants and controls without momentary LBP, the question that arises is what additional knowledge can be attained. Three underlying traits seem to be relevant about LBP-resilient participants: personality, favourable work conditions and subjective attitudes/attributions towards health. These rationales have to be considered with respect to LBP prevention.

Variability of blood lactate during and between given constant prolonged cycling power.

AIM: Blood lactate concentration (BLC) has been the basis of rational performance diagnostics for almost five decades. Aim of this study was to identify the variability of the BLC during repeated constant power tests (VC-BLC) and to quantify the corresponding variability of changes in the BLC over time (VC-BLC-Difference). METHODS: Twelve healthy male subjects (24.8±3-8 years, 182.9±7.5 cm, 75.7±7.1 kg, ·VO2peak: 4.1±0.6 l min-1) performed four series of three constant power tests at exercise intensities of 45% (A), 60% (B), 75% (C) and 90% (D) of VO2peak. Blood sampling was conducted before, at the end of every 5th min and at the end of each test terminated ahead of schedule. RESULTS: BLC was different at all exercise intensities from minute five onwards. Power output was equivalent to 142.1±18.9 W (A), 196.3±25.2 W (B), 247.9±30.3 W (C) and 302.5±38.4 W (D). VC-BLC varied between 9±2.2% and 21±10.1%. VC-BLC and VC-BLC-Difference between 10th and 30th min correlated inversely with mean BLC level and BLC-Difference respectively. CONCLUSION: By providing first data on constant power test VC-BLC and VC-BLC-Difference this study might help to improve performance diagnostics and training control in sports medicine and medical exercise therapy by assisting in selecting and monitoring exercise intensity. Performance monitoring with BLC-Differences is feasible at moderate and high exercise intensities; single BLC measurements at termination of tests might not be sufficient.

Resources for preventing sickness absence due to low back pain.

BACKGROUND: After an episode of non-specific low back pain (LBP) some individuals fail to return to work. The factors leading to such LBP-related sickness absence are not yet fully understood. AIMS: To identify individual resources, over and above the already established predictors, for preventing LBP-related sickness absence in a population-based sample of workers experiencing an episode of LBP. METHODS: Cohort study with 1-year follow-up. Participants were from a working population who reported an episode of acute or subacute LBP at baseline. Four potential resources-life satisfaction, doing sports, job satisfaction and social support at work-were examined for their incremental value in predicting sickness absence over and above baseline sickness absence and fear-avoidance beliefs about work. RESULTS: In all, 279 workers participated in the study. All four resources showed an inverse relationship with regard to sickness absence. A multiple regression analysis revealed that life satisfaction as a resource protected against sickness absence, when controlling for established risk factors. Job satisfaction and social support at work minimized the influence of sickness absence at baseline and at 1-year follow-up. CONCLUSIONS: In a non-clinical working sample of individuals experiencing an acute/subacute episode of LBP, life satisfaction was a unique predictor of sickness absence after 1 year. Prevention in the occupational setting should not only address common risk factors but also occupational and individual resources that keep workers satisfied with life despite having LBP.

[Efficacy, utility and cost-effectiveness of multidisciplinary treatment for chronic low back pain]. / Wirksamkeit, Zweckmässigkeit und Wirtschaftlichkeit des multimodalen Behandlungsansatzes bei chronisch lumbalen Rückenschmerzen.

BACKGROUND: Qualitative criteria, such as efficacy, utility and cost-effectiveness are essential for insurance and reimbursement companies to meet the costs for a multidisciplinary treatment (MDT) for persons with chronic low back pain (CLBP). METHOD: A systematic search concerning the qualitative criteria of MDT for CLBP presents an overview of the current literature. RESULTS: The search revealed 8 systematic reviews which document a moderate efficacy of MDT as a treatment for persons with CLBP although some reported restrictions. Analysis of 6 studies that have not yet been included in previous reviews confirmed the findings from these reviews. The comparison of conservative and surgical treatment for CLBP revealed that long-term outcomes hardly differed in quality, whereas surgical treatment was more expensive and contained more and higher risks. References on moderate to high cost-effectiveness of MDT are represented in 3 original studies. CONCLUSION: The MDT of CLBP is moderately efficient, purposeful, cost-effective and demonstrate an alternative treatment form to surgical treatment.

Age at hip or knee joint replacement surgery predicts likelihood of revision surgery.

We compared revision and mortality rates of 4668 patients undergoing primary total hip and knee replacement between 1989 and 2007 at a University Hospital in New Zealand. The mean age at the time of surgery was 69 years (16 to 100). A total of 1175 patients (25%) had died at follow-up at a mean of ten years post-operatively. The mean age of those who died within ten years of surgery was 74.4 years (29 to 97) at time of surgery. No change in comorbidity score or age of the patients receiving joint replacement was noted during the study period. No association of revision or death could be proven with higher comorbidity scoring, grade of surgeon, or patient gender. We found that patients younger than 50 years at the time of surgery have a greater chance of requiring a revision than of dying, those around 58 years of age have a 50:50 chance of needing a revision, and in those older than 62 years the prosthesis will normally outlast the patient. Patients over 77 years old have a greater than 90% chance of dying than requiring a revision whereas those around 47 years are on average twice as likely to require a revision than die. This information can be used to rationalise the need for long-term surveillance and during the informed consent process.

Predicting the transition from acute to persistent low back pain.

BACKGROUND: Most people experience low back pain (LBP) at least once in their lifetime. Only a minority of them go on to develop persistent LBP. However, the socioeconomic costs of persistent LBP significantly exceed the costs of the initial acute LBP episode. AIMS: To identify factors that influence the progression of acute LBP to the persistent state at an early stage. METHODS: Prospective inception cohort study of patients attending a health practitioner for their first episode of acute LBP or recurrent LBP after a pain free period of at least 6 months. Patients were assessed at baseline addressing occupational and psychological factors as well as pain, disability, quality of life and physical activity and followed up at 3, 6, 12 weeks and 6 months. Variables were combined to the three indices 'working condition', 'depression and maladaptive cognitions' and 'pain and quality of life'. RESULTS: The index 'depression and maladaptive cognitions' was found to be a significant baseline predictor for persistent LBP up to 6 months (OR 5.1; 95% CI: 1.04-25.1). Overall predictive accuracy of the model was 81%. CONCLUSIONS: In this study of patients with acute LBP in a primary care setting psychological factors at baseline correlated with a progression to persistent LBP up to 6 months. The benefit of including factors such as 'depression and maladaptive cognition' in screening tools is that these factors can be addressed in primary and secondary prevention.

Development of a documentation instrument for the conservative treatment of spinal disorders in the International Spine Registry, Spine Tango.

Spine Tango is the first and only International Spine Registry in operation to date. So far, only surgical spinal interventions have been recorded and no comparable structured and comprehensive documentation instrument for conservative treatments of spinal disorders is available. This study reports on the development of a documentation instrument for the conservative treatment of spinal disorders by using the Delphi consensus method. It was conducted with a group of international experts in the field. We also assessed the usability of this new assessment tool with a prospective feasibility study on 97 outpatients and inpatients with low back or neck pain undergoing conservative treatment. The new 'Spine Tango conservative' questionnaire proved useful and suitable for the documentation of pathologies, conservative treatments and outcomes of patients with low back or neck problems. A follow-up questionnaire seemed less important in the predominantly outpatient setting. In the feasibility study, between 43 and 63% of patients reached the minimal clinically important difference in pain relief and Core Outcome Measures Index at 3 months after therapy; 87% of patients with back pain and 85% with neck pain were satisfied with the received treatment. With 'Spine Tango conservative' a first step has been taken to develop and implement a complementary system for documentation and evaluation of non-surgical spinal interventions and outcomes within the framework of the International Spine Registry. It proved useful and feasible in a first pilot study, but it will take the experience of many more cases and therapists to develop a version similarly mature as the surgical instruments of Spine Tango.

How to Tango: a manual for implementing Spine Tango.

The generic approach of the Spine Tango documentation system, which uses web-based technologies, is a necessity for reaching a maximum number of participants. This, in turn, reduces the potential for customising the Tango according to the individual needs of each user. However, a number of possibilities still exist for tailoring the data collection processes to the user's own hospital workflow. One can choose between a purely paper-based set-up (with in-house scanning, data punching or mailing of forms to the data centre at the University of Bern) and completely paper-free online data entry. Many users work in a hybrid mode with online entry of surgical data and paper-based recording of the patients' perspectives using the Core Outcome Measures Index (COMI) questionnaires. Preoperatively, patients can complete their questionnaires in the outpatient clinic at the time of taking the decision about surgery or simply at the time of hospitalisation. Postoperative administration of patient data can involve questionnaire completion in the outpatient clinic, the handing over the forms at the time of discharge for their mailing back to the hospital later, sending out of questionnaires by post with a stamped addressed envelope for their return or, in exceptional circumstances, conducting telephone interviews. Eurospine encourages documentation of patient-based information before the hospitalisation period and surgeon-based information both before and during hospitalisation; both patient and surgeon data should be acquired for at least one follow-up, at a minimum of three to six months after surgery. In addition, all complications that occur after discharge, and their consequences should be recorded.

Benchmarking with Spine Tango: potentials and pitfalls.

The newly released online statistics function of Spine Tango allows comparison of own data against the aggregated results of the data pool that all other participants generate. This comparison can be considered a very simple way of benchmarking, which means that the quality of what one organization does is compared with other similar organizations. The goal is to make changes towards better practice if benchmarking shows inferior results compared with the pool. There are, however, pitfalls in this simplified way of comparing data that can result in confounding. This means that important influential factors can make results appear better or worse than they are in reality and these factors can only be identified and neutralized in a multiple regression analysis performed by a statistical expert. Comparing input variables, confounding is less of a problem than comparing outcome variables. Therefore, the potentials and limitations of automated online comparisons need to be considered when interpreting the results of the benchmarking procedure.

Identification of prognostic factors for chronicity in patients with low back pain: a review of screening instruments.

Low back pain (LBP) is currently the most prevalent and costly musculoskeletal problem in modern societies. Screening instruments for the identification of prognostic factors in LBP may help to identify patients with an unfavourable outcome. In this systematic review screening instruments published between 1970 and 2007 were identified by a literature search. Nine different instruments were analysed and their different items grouped into ten structures. Finally, the predictive effectiveness of these structures was examined for the dependent variables including "work status", "functional limitation", and "pain". The strongest predictors for "work status" were psychosocial and occupational structures, whereas for "functional limitation" and "pain" psychological structures were dominating. Psychological and occupational factors show a high reliability for the prognosis of patients with LBP. Screening instruments for the identification of prognostic factors in patients with LBP should include these factors as a minimum core set.

Patient characteristics differently affect early cup and stem loosening in THA: a case-control study on 7,535 patients.

We postulated that certain patient characteristics have different effects on early THA component loosening. With two matched case-control studies we assessed 3,028 cups and 5,224 stems. Loosening was defined using signs of mechanical component failure on routine follow-up radiographs or revision for aseptic loosening. Women and men had similar cup-loosening odds, but women had lower odds for stem loosening (p < 0.0001). Odds for cup loosening decreased by 2.1% per additional year of age (p = 0.0004), those for stem loosening by 2.4% (p < 0.0001). Each additional kilogram of weight decreased cup loosening odds by 1.3% (p = 0.0051). Each additional unit of BMI increased stem loosening odds (p = 0.0109). Charnley classes B and C were protective factors against loosening of both components. There were no risk differences for the various main diagnoses. Certain patient characteristics differently affected early cup and stem loosening, although some characteristics had the same protective or harmful effect on component survival.