A discrete choice experiment to identify the most efficient quality indicators for the supervision of psychiatric hospitals.

BACKGROUND: In the Netherlands, health care is regulated by the Health and Youth Care Inspectorate. Forty-six indicators are used to prioritize supervision of psychiatric hospitals. The objective of this study is to define a smaller set of weighted indicators which reflects a consensus among inspectors about which aspects are most important for risk assessment. METHODS: The set of 46 indicators, complemented with missing information, was reduced to six indicators by means of interviews, group discussions and ranking among the inspectors. These indicators were used as attributes in a discrete choice experiment (DCE) to define their weights. RESULTS: Twenty-six inspectors defined the top four indicators suitable for the risk assessment of psychiatric hospitals. These are: the policy on prevention of compulsory treatment; the policy on dysfunctional professionals; the quality of internal research after a serious incident; and the implementation of multidisciplinary guidelines on suicidal behaviour. These indicators share the same importance with regard to risk assessment. The screening of somatic symptoms and the policy on integrated care are important indicators too, but less relevant. CONCLUSION: Through a DCE, we reduced the amount of information for risk assessment of psychiatric hospitals to six weighted indicators. Inspectors can use these indicators to prioritize their inspections.

Prediction of bladder outcomes after ischemic spinal cord injury: A longitudinal cohort study from the European multicenter study about spinal cord injury.

OBJECTIVE: The recovery of bladder function after spinal cord injury (SCI) is of major importance for patients and caregivers. We recently developed prediction models of bladder outcomes (defined as the capacity of storing the urine and emptying completely the bladder) 1 year after a SCI of traumatic etiology and investigated if these models would also be applicable to patients with ischemic SCI. PATIENTS AND METHODS: From the European multicenter study about spinal cord injury (EMSCI), we extracted data of all ischemic SCI patients with available neurological and functional data (according to the International Standards for Neurological Classification of Spinal Cord Injury, ISNCSCI, and Spinal Cord Independence Measure, SCIM) within 40 days and bladder outcomes 1 year after ischemia. The model relies on three predictors: strength of the legs, the presence of sensation in the S3 dermatome, and the part of the SCIM assessing breathing and bladder and bowel control. A simplified model relying on leg strength only was also tested. Bladder outcomes were evaluated according to the score of item six of SCIM. RESULTS: In total 85 patients (56 males (66%), mean age 55 years) were included. Twenty-three patients (27%) showed complete bladder function recovery one year after ischemia. Both models showed a very good predictive power: the area under the receiver operating characteristics curve (aROC) of the two models was 0.825 and 0.822, respectively. CONCLUSIONS: Comparable to acute traumatic SCI, also in ischemic SCI the outcome of full bladder function recovery can be predicted by clinical scores, and prediction models of bladder outcomes may be applicable in clinical trials.

Effectiveness of a multicomponent self-management intervention for adults with epilepsy (ZMILE study): A randomized controlled trial.

BACKGROUND: The objective of the ZMILE study was to compare the effectiveness of a multicomponent self-management intervention (MCI) with care as usual (CAU) in adult patients with epilepsy (PWE) over a six-month period. METHODS: Participants (PWE & relative) were randomized into intervention or CAU groups. Self-report questionnaires were used to measure disease-specific self-efficacy as the primary outcome measure and general self-efficacy, adherence, seizure severity, emotional functioning, quality of life, proactive coping, and side-effects of antiepileptic drugs (AED) as secondary outcome measures. Instruments used at baseline and during a six-month follow-up period were the following: disease-specific self-efficacy (Epilepsy Self-Efficacy Scale [ESES], General Self-Efficacy Scale [GSES]); adherence (Medication Adherence Scale [MARS] and Medication Event Monitoring System [MEMS]); seizure severity (National Hospital Seizure Severity Scale [NHS3]); emotional well-being (Hospital Anxiety and Depression Scale [HADS]); quality of life (Quality of Life in Epilepsy [QOLIE-31P]); proactive coping (Utrecht Proactive Coping Competence [UPCC]); and side-effects of antiepileptic drugs [SIDAED]. Multilevel analyses were performed, and baseline differences were corrected by inclusion of covariates in the analyses. RESULTS: In total, 102 PWE were included in the study, 52 of whom were in the intervention group. On the SIDAED and on three of the quality of life subscales QOLIE-31P, a significant difference was found (p<0.05) in the intervention group. Self-efficacy, however, showed no significant differences between the MCI and the CAU groups. None of the other outcome measures showed any significant difference between the two groups. SIGNIFICANCE: Although we found no statistically significant difference in the primary outcome measure, disease-specific self-efficacy, this MCI could prove promising, since we found improvement in some domains of quality of life in epilepsy scale and a decrease in AED side-effects in the MCI group compared with the CAU group.

No Transfer of Pressure to Adjacent Discs During Human Low-Pressure Controlled Discography: A Prospective Clinical Study.

Background: A substantial part of low back pain (LBP) originates from degeneration of the intervertebral disc. To confirm the diagnosis of discogenic pain, provocation discography seems the best available tool. However, provocation discography is also considered to be a controversial and subjective test because the patient's personal pain response is the most crucial for the result of the test. Recently, an in vivo porcine study and a study in nine human subjects showed passing of pressure to the adjacent discs during discography. This could mean that the concordant pain the patient describes originates from an adjacent disc. The object of this study is to assess if during human lumbar pressure-controlled provocation discography there is pressure transmission to adjacent discs. Methods: Consecutive patients between age 18 and 65 years with intractable low back pain and at least 50% preserved height of the suspected painful disc were included. Exclusion criteria were prior lumbar surgery of the suspected level, use of anticoagulants, pregnancy, local infection, and iodine allergy. An arterial blood pressure monitoring system simultaneously assessed the pressure in the adjacent discs while low-speed flow, pressure-controlled discography was performed. Results: In 50 patients with a positive discography, the average intradiscal peak pressure was 15.1 psi (SD = 11.1). In 48 procedures, no pressure rise in the adjacent discs was found. A small pressure rise (1.1 psi) in the adjacent disc during discography was recorded in two patients. Conclusions: Pressure rise in adjacent discs does not seem to occur during low-speed flow pressure-controlled lumbar provocation discography. False-positive pain reactions caused by potentially painful adjacent discs are therefore unlikely during pressure-controlled discography.

Prediction of Bladder Outcomes after Traumatic Spinal Cord Injury: A Longitudinal Cohort Study.

BACKGROUND: Neurogenic bladder dysfunction represents one of the most common and devastating sequelae of traumatic spinal cord injury (SCI). As early prediction of bladder outcomes is essential to counsel patients and to plan neurourological management, we aimed to develop and validate a model to predict urinary continence and complete bladder emptying 1 y after traumatic SCI. METHODS AND FINDINGS: Using multivariate logistic regression analysis from the data of 1,250 patients with traumatic SCI included in the European Multicenter Spinal Cord Injury study, we developed two prediction models of urinary continence and complete bladder emptying 1 y after traumatic SCI and performed an external validation in 111 patients. As predictors, we evaluated age, gender, and all variables of the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) and of the Spinal Cord Independence Measure (SCIM). Urinary continence and complete bladder emptying 1 y after SCI were assessed through item 6 of SCIM. The full model relies on lower extremity motor score (LEMS), light-touch sensation in the S3 dermatome of ISNCSI, and SCIM subscale respiration and sphincter management: the area under the receiver operating characteristics curve (aROC) was 0.936 (95% confidence interval [CI]: 0.922-0.951). The simplified model is based on LEMS only: the aROC was 0.912 (95% CI: 0.895-0.930). External validation of the full and simplified models confirmed the excellent predictive power: the aROCs were 0.965 (95% CI: 0.934-0.996) and 0.972 (95% CI 0.943-0.999), respectively. This study is limited by the substantial number of patients with a missing 1-y outcome and by differences between derivation and validation cohort. CONCLUSIONS: Our study provides two simple and reliable models to predict urinary continence and complete bladder emptying 1 y after traumatic SCI. Early prediction of bladder function might optimize counselling and patient-tailored rehabilitative interventions and improve patient stratification in future clinical trials.

Methods for Handling Missing Variables in Risk Prediction Models.

Prediction models should be externally validated before being used in clinical practice. Many published prediction models have never been validated. Uncollected predictor variables in otherwise suitable validation cohorts are the main factor precluding external validation. We used individual patient data from 9 different cohort studies conducted in the United States, Europe, and Latin America that included 7,892 patients with chronic obstructive pulmonary disease who enrolled between 1981 and 2006. Data on 3-year mortality and the predictors of age, dyspnea, and airflow obstruction were available. We simulated missing data by omitting the predictor dyspnea cohort-wide, and we present 6 methods for handling the missing variable. We assessed model performance with regard to discriminative ability and calibration and by using 2 vignette scenarios. We showed that the use of any imputation method outperforms the omission of the cohort from the validation, which is a commonly used approach. Compared with using the full data set without the missing variable (benchmark), multiple imputation with fixed or random intercepts for cohorts was the best approach to impute the systematically missing predictor. Findings of this study may facilitate the use of cohort studies that do not include all predictors and pave the way for more widespread external validation of prediction models even if 1 or more predictors of the model are systematically missing.

Predictors of anticoagulation quality in 15 834 patients performing patient self-management of oral anticoagulation with vitamin K antagonists in real-life practice: a survey of the International Self-Monitoring Association of Orally Anticoagulated Patients.

Although patient self-management (PSM) of oral anticoagulation with vitamin K antagonists is recommended for patients requiring long-term anticoagulation, important aspects are still unclear. Using data from a large international survey (n = 15 834; median age 72 years; 30·1% female), we studied predictors of poor anticoagulation control (percentage of International Normalized Ratio values within therapeutic range below 75%) and developed a simple prediction model. The following variables were identified as risk factors for poor anticoagulation control and included in the final model: higher intensity of therapeutic range (odds ratio [OR] on every level 1·9; 95% confidence interval [CI] 1·8-2·0), long intervals between measurements (>14 d; 1·5; 95% CI 1·3-1·7), female sex (OR 1·3; 95% CI 1·2-1·4), and management other than PSM (OR 1·4; 95% CI 1·2-1·6). At a threshold of 0·2 (at least one variable present), the model predicted poor anticoagulation control with a sensitivity of 85·3% (95% CI: 84·0, 86·4) and a specificity of 28·5% (27·6, 29·5). The area under the receiver operated characteristic curve was 0·65. Using the proposed prediction model, physicians will be able to identify patients with a low chance of performing well, considering additional training, regular follow-up, or adjustment of therapeutic ranges.

Predictive Factors for Successful Outcome of Pulsed Radiofrequency Treatment in Patients with Intractable Lumbosacral Radicular Pain.

BACKGROUND: In a previous prospective study on pulsed radiofrequency (PRF) treatment adjacent to the lumbar dorsal root ganglion (DRG) for patients with chronic lumbosacral radicular pain, we reported success in 55.4% of the patients at 6 months. Identification of predictors for success after PRF may improve outcome. We assessed the predictors of PRF in patients with chronic intractable lumbosacral radicular pain. METHODS: Patients with monosegmental chronic lumbosacral radicular pain of L5 or S1 first received a selective nerve root block at the corresponding level. Independent of the result of this block a PRF treatment at the same level was performed. At 6 weeks, 3 months, and 6 months after the procedure the outcome was evaluated. RESULTS: A positive diagnostic nerve root block and age ≥ 55 were predictive factors for successful outcome at 6 months, while disability was a negative predictor.The use of failed back surgery syndrome, gender, duration of pain, Numerical Rating Scale, level and side of treatment, DN4, and RAND-36 as predictors for success was not supported. CONCLUSIONS: Successful outcome after PRF adjacent to the DRG, in patients with intractable chronic lumbosacral radicular pain, is more likely in patients ≥ 55 years, with limited disability and after a positive diagnostic nerve root block. A combination of all these factors creates a fair predictive value (AUC: 0.73).

Faecal calprotectin in suspected paediatric inflammatory bowel disease.

OBJECTIVES: The diagnostic accuracy of faecal calprotectin (FC) concentration for paediatric inflammatory bowel disease (IBD) is well described at the population level, but not at the individual level. We reassessed the diagnostic accuracy of FC in children with suspected IBD and developed an individual risk prediction rule using individual patient data. METHODS: MEDLINE, EMBASE, DARE, and MEDION databases were searched to identify cohort studies evaluating the diagnostic performance of FC in paediatric patients suspected of having IBD. A standard study-level meta-analysis was performed. In an individual patient data meta-analysis, we reanalysed the diagnostic accuracy on a merged patient dataset. Using logistic regression analysis we investigated whether and how the FC value and patient characteristics influence the diagnostic precision. A prediction rule was derived for use in clinical practice and implemented in a spreadsheet calculator. RESULTS: According to the study-level meta-analysis (9 studies, describing 853 patients), FC has a high overall sensitivity of 0.97 (95% confidence interval [CI] 0.92-0.99) and a specificity of 0.70 (0.59-0.79) for diagnosing IBD. In the patient-level pooled analysis of 742 patients from 8 diagnostic accuracy studies, we calculated that at an FC cutoff level of 50 µg/g there would be 17% (95% CI 15-20) false-positive and 2% (1-3) false-negative results. The final logistic regression model was based on individual data of 545 patients and included both FC level and age. The area under the receiver operating characteristic curve of this derived prediction model was 0.92 (95% CI 0.89-0.94). CONCLUSIONS: In high-prevalence circumstances, FC can be used as a noninvasive biomarker of paediatric IBD with only a small risk of missing cases. To quantify the individual patients' risk, we developed a simple prediction model based on FC concentration and age. Although the derived prediction rule cannot substitute the clinical diagnostic process, it can help in selecting patients for endoscopic evaluation.

Pulsed radiofrequency for chronic intractable lumbosacral radicular pain: a six-month cohort study.

BACKGROUND AND OBJECTIVES: There is little evidence concerning the medical management of lumbosacral radicular pain. The prognosis for patients suffering pain for more than 3 months is poor. Pulsed radiofrequency (PRF) treatment of the dorsal root ganglion (DRG) has been suggested as a minimally invasive treatment. We studied the effect on pain and quality of life of PRF treatment of the DRG in patients with chronic, severe lumbosacral radicular pain. METHODS: Patients with lumbosacral radicular pain were screened to select a homogeneous population. PRF treatment of the DRG was performed at L5 or S1. Evaluation was carried out at 6 weeks, 3 months, and 6 months. Pain reduction and "fully recovered" or "much improvement," in terms of the global perceived effect, were the primary outcomes. Quality of life (RAND-36), disability (Oswestry Disability Index), and the neuropathic pain scales leeds assessment of neuropathic symptoms and signs (LANSS) and DN4 were registered at each time point. Medication use was scored with the Medication Quantification Scale. RESULTS: Out of 461 screened patients, 65 were included. According to the intention to treat analysis, clinical success was achieved in 56.9%, 52.3%, and 55.4% of the patients at respectively 6 weeks, 3 months, and 6 months. DN4, Oswestry Disability Index and physical component for the RAND-36 quality of life improved significantly while the mental component remained unchanged. The number of patients on opioids was reduced. CONCLUSIONS: PRF treatment of the DRG may be considered for patients with chronic, severe lumbosacral radicular pain refractory to conventional medical management.

Protocol for a randomized, placebo-controlled, double-blind clinical trial investigating sacral neuromodulation for neurogenic lower urinary tract dysfunction.

BACKGROUND: Sacral neuromodulation has become a well-established and widely accepted treatment for refractory non-neurogenic lower urinary tract dysfunction, but its value in patients with a neurological cause is unclear. Although there is evidence indicating that sacral neuromodulation may be effective and safe for treating neurogenic lower urinary tract dysfunction, the number of investigated patients is low and there is a lack of randomized controlled trials. METHODS AND DESIGN: This study is a prospective, randomized, placebo-controlled, double-blind multicenter trial including 4 sacral neuromodulation referral centers in Switzerland. Patients with refractory neurogenic lower urinary tract dysfunction are enrolled. After minimally invasive bilateral tined lead placement into the sacral foramina S3 and/or S4, patients undergo prolonged sacral neuromodulation testing for 3-6 weeks. In case of successful (defined as improvement of at least 50% in key bladder diary variables (i.e. number of voids and/or number of leakages, post void residual) compared to baseline values) prolonged sacral neuromodulation testing, the neuromodulator is implanted in the upper buttock. After a 2 months post-implantation phase when the neuromodulator is turned ON to optimize the effectiveness of neuromodulation using sub-sensory threshold stimulation, the patients are randomized in a 1:1 allocation in sacral neuromodulation ON or OFF. At the end of the 2 months double-blind sacral neuromodulation phase, the patients have a neuro-urological re-evaluation, unblinding takes place, and the neuromodulator is turned ON in all patients. The primary outcome measure is success of sacral neuromodulation, secondary outcome measures are adverse events, urodynamic parameters, questionnaires, and costs of sacral neuromodulation. DISCUSSION: It is of utmost importance to know whether the minimally invasive and completely reversible sacral neuromodulation would be a valuable treatment option for patients with refractory neurogenic lower urinary tract dysfunction. If this type of treatment is effective in the neurological population, it would revolutionize the management of neurogenic lower urinary tract dysfunction. TRIAL REGISTRATION NUMBER: http://www.clinicaltrials.gov; Identifier: NCT02165774.

Controlled-release oxycodone versus naproxen at home after ambulatory surgery: a randomized controlled trial.

BACKGROUND: Strong opioids in the home setting after ambulatory surgery have rarely been studied for fear of hazardous adverse effects such as respiratory depression. OBJECTIVES: We compared the efficacy of paracetamol/controlled-release (CR) oxycodone and paracetamol/naproxen for treatment of acute postoperative pain at home after ambulatory surgery. Secondary outcomes were adverse effects of study medication, treatment satisfaction, and postoperative analgesic compliance. METHODS: Patients undergoing ambulatory knee arthroscopy or inguinal hernia repair surgery (n = 105) were randomized into 3 groups: Group1 paracetamol/naproxen (n = 35), Group 2 paracetamol/CR oxycodone for 24 hours (n = 35), and Group 3 paracetamol/CR oxycodone for 48 hours (n = 35). Pain intensity at movement and at rest using a visual analog scale as well as satisfaction with postoperative analgesia and side effects were recorded for up to 48 hours postoperatively. Compliance with study medication was also assessed. RESULTS: For pain at movement and at rest, no significant differences were found between the paracetamol/naproxen group and either the paracetamol/CR oxycodone for 24 hours group (ß = 2.6 [4.9]; P = 0.597) or the paracetamol/CR oxycodone for 48 hours (ß = -1.7 [5.1]; P = 0.736). No major adverse effects of study medication were registered and satisfaction with postoperative pain treatment was high in all groups. Compliance was comparable across the groups. Despite clear instructions, 8 patients with the lowest pain scores did not use any of the prescribed pain medication. CONCLUSIONS: Paracetamol/CR oxycodone and paracetamol/naproxen are equally effective in treatment of acute postoperative pain at home after ambulatory surgery with comparable patient satisfaction level. We suggest paracetamol/CR oxycodone to be a valuable alternative for the current paracetamol/naproxen gold standard, particularly in patients with a contraindication for nonsteroidal anti-inflammatory drugs. ClinicalTrials.gov identifier: NCT02152592.

Long-term follow-up of cervical facet medial branch radiofrequency treatment with the single posterior-lateral approach: an exploratory study.

BACKGROUND: Over 50% of patients presenting to pain clinic with neck pain have the cervical facet joints as the source of pain. Radiofrequency (RF) treatment of the medial branch, innervating the facet joint, is a therapeutic option. The objectives of this study were to evaluate the therapeutic effect and its duration of RF treatment, using the single posterior-lateral approach in patients suffering from facet joint degeneration and to identify predictors for a long-term effect. METHODS: Of the 130 consecutive patients with axial neck pain referred to the University Pain Center Maastricht, 67 fulfilled the inclusion criteria. The therapeutic effect was measured using the Patients' Global Impression of Change (PGIC) scale. Retrospective data were made complete using newly collected PGIC follow-up data. A Kaplan-Meier curve evaluated the long-term therapeutic effect. Possible predictors of outcome were evaluated. RESULTS: Two patients refused to participate and in the remaining 65 patients, overall pain relief was reported in 55.4% at 2-month follow-up. Moderately, important change of improvement and substantial change of improvement were seen in 50.8% of patients. At 3-year follow-up, 30% still reported pain reduction. Spinal treatment level was the only predictor found. CONCLUSIONS: Radiofrequency treatment of the cervical facet joints using a single posterior-lateral approach is a promising technique in patients with chronic neck pain due to facet degeneration. The short-term and long-term therapeutic effects of this intervention justify a randomized controlled trial to estimate the efficacy of cervical facet joint RF treatment in a chronic neck pain population.

Detection of coronary plaques using MR coronary vessel wall imaging: validation of findings with intravascular ultrasound.

OBJECTIVES: Compared with X-ray coronary angiography (CAG), magnetic resonance imaging of the coronary vessel wall (MR-CVW) may provide more information about plaque burden and coronary remodelling. We compared MR-CVW with intravascular ultrasound (IVUS), the standard of reference for coronary vessel wall imaging, with regard to plaque detection and wall thickness measurements. METHODS: In this study 17 patients with chest pain, who had been referred for CAG, were included. Patients underwent IVUS and MR-CVW imaging of the right coronary artery (RCA). Subsequently, the coronary vessel wall was analysed for the presence and location of coronary plaques. RESULTS: Fifty-two matching RCA regions of interest were available for comparison. There was good agreement between IVUS and MR-CVW for qualitative assessment of presence of disease, with a sensitivity of 94% and specificity of 76%. Wall thickness measurements demonstrated a significant difference between mean wall thickness on IVUS and MR-CVW (0.48 vs 1.24 mm, P < 0.001), but great heterogeneity between wall thickness measurements, resulting in a low correlation between IVUS and MR-CVW. CONCLUSIONS: MR-CVW has high sensitivity for the detection of coronary vessel wall thickening in the RCA compared with IVUS. However, the use of MRI for accurate absolute wall thickness measurements is not supported when a longitudinal acquisition orientation is used.

Randomized comparison between the cemented Scientific Hip Prosthesis and Omnifit: 2-year DEXA and minimum 10-year clinical follow-up.

Radiostereometry (RSA) of the cemented Scientific Hip Prosthesis (SHP) reported excessive migration and predicted high failure rates. In a prospective randomized clinical trial we compared minimum 10 years results of the SHP (n=38) with the Omnifit-stem (n=37). Two-year bone remodelling, compared with dual energy x-ray absorptiometry and assessed in regions of interest A-D based on the 7 Gruen zones, showed better periprosthetic bone preservation around the SHP in all but one regions (P<.05). At 10 years Harris Hip Score was better for the SHP (P=.0001) but Oxford Hip Score was the same (P=.79). There were no revisions in either group, but radiographic loosening was definite in 1 SHP and 1 Omnifit. Based on earlier RSA studies, the rough surface finish of the SHP was expected to cause cement abrasion, osteolysis and inferior survival. However our clinical and remodelling results could not confirm these expectations, suggesting that the link of early migration and mid-term clinical results is not sufficiently clear for the SHP.

Spinal cord stimulation for complex regional pain syndrome type I: a prospective cohort study with long-term follow-up.

OBJECTIVES: Spinal cord stimulation (SCS) is an effective treatment for intractable complex regional pain syndrome type I pain. Long-term data are scarce on effectiveness, degree of pain relief, predictors, and complications. MATERIALS AND METHODS: From 1997 to 2008, 84 consecutive patients who received an implanted SCS system after positive test stimulation were included in the prospective study. Treatment effectiveness was assessed annually as measured by mean visual analog scale pain scores and with the Patients Global Impression of Change scale. Treatment success was defined as at least 30% mean pain relief at end point and treatment failure as explantation of the system. A Cox regression determined if baseline factors were associated with both these outcomes. RESULTS: During 11 years, 41% (95% CI: 27-55) of the patients experience at least 30% pain relief at assessment end point. During 12 years of follow-up 63% (95%CI: 41-85) of the implanted patients still use their SCS device at measured end point. Pain relief of at least 50% one week following test stimulation is associated with a higher probability of long-term treatment success. In 51 patients, 122 reinterventions were performed over 12 years; 13 were due to complications, 44 to battery changes, and 65 reinterventions were equipment related. CONCLUSION: SCS provides an effective long-term pain treatment for 63% (95%CI: 41-85) of implanted patients. Forty-one percent (95%CI: 27-55) of SCS treated patients have at least 30% pain reduction at measurement end point. The number of reinterventions after implantation due to equipment-related problems, battery changes, and complications is 122 over 12 years of follow-up. Sixty-one percent (N = 51) of the patients had at least one reintervention. Mean pain relief of at least 50% (visual analog scale) one week after the test stimulation is associated with long-term treatment success.

Good results in postoperative and hematogenous deep infections of 89 stable total hip and knee replacements with retention of prosthesis and local antibiotics.

BACKGROUND: Deep postoperative and hematogenous prosthesis infections may be treated with retention of the prosthesis, if the prosthesis is stable. How long the infection may be present to preclude a good result is unclear. PATIENTS AND METHODS: We retrospectively studied 89 deep-infected stable prostheses from 69 total hip replacements and 20 total knee replacements. There were 83 early or delayed postoperative infections and 6 hematogenous. In the postoperative infections, treatment had started 12 days to 2 years after implantation. In the hematogenous infections, symptoms had been present for 6 to 9 days. The patients had been treated with debridement, prosthesis retention, systemic antibiotics, and local antibiotics: gentamicin-PMMA beads or gentamicin collagen fleeces. The minimum follow-up time was 1.5 years. We investigated how the result of the treatment had been influenced by the length of the period the infection was present, and by other variables such as host characteristics, infection stage, and type of bacteria. RESULTS: In postoperative infections, the risk of failure increased with a longer postoperative interval: from 0.2 (95% CI: 0.1-0.3) if the treatment had started ≥ 4 weeks postoperatively to 0.5 (CI: 0.2-0.8) if it had started at ≥ 8 weeks. The relative risk for success was 0.6 (CI: 0.3-0.95) if the treatment had started ≥ 8 weeks. In the hematogenous group, 5 of 6 infections had been treated successfully. INTERPRETATION: A longer delay before the start of the treatment caused an increased failure rate, but this must be weighed against the advantage of keeping the prosthesis. We consider a failure rate of < 50% to be acceptable, and we therefore advocate keeping the prosthesis for up to 8 weeks postoperatively, and in hematogenous infections with a short duration of symptoms.

Individual patient data meta-analysis of diagnostic studies: opportunities and challenges.

Individual patient data meta-analyses using the raw data from primary diagnostic accuracy studies are taking hold in systematic reviews evaluating tests. Conventional reviews and meta-analyses that summarise study-level data on test accuracy (sensitivity and specificity) have several disadvantages. The most fundamental limitation of this approach is that it estimates the rates of test result-given disease (sensitivity is probability of positive test result-given disease is present; and specificity is probability of negative test result-given disease is absent). This may be addressed by summarising predictive values, but estimating accuracy for individual tests without consideration of other tests in the test chains that make up everyday diagnostic work-ups remain a problem. To inform clinical practice it is essential that test evaluation generates information about probability of disease given test results, and that it does so in view of the preceding contribution to diagnosis of other tests, for example, symptoms and signs. A multivariable (logistic regression) framework generates disease probabilities taking into account the important factors that play a role in diagnosis. Most primary accuracy studies lack statistical power to do this, particularly because of the small absolute number of disease events per test included in the diagnostic work. Synthesis using their raw data can overcome this problem, but meta-analysts will have limited success if there are difficulties in obtaining the large majority of valid studies, without 'missing' data on the tests relevant in clinical decision-making. Successful individual patient data meta-analyses create the opportunity to calculate directly and reliably disease probabilities corresponding with realistic chains of tests, thereby making outputs of reviews of test accuracy clinically applicable.

Geometrical models for cardiac MRI in rodents: comparison of quantification of left ventricular volumes and function by various geometrical models with a full-volume MRI data set in rodents.

MRI has been proven to be an accurate method for noninvasive assessment of cardiac function. One of the current limitations of cardiac MRI is that it is time consuming. Therefore, various geometrical models are used, which can reduce scan and postprocessing time. It is unclear how appropriate their use is in rodents. Left ventricular (LV) volumes and ejection fraction (EF) were quantified based on 7.0 Tesla cine-MRI in 12 wild-type (WT) mice, 12 adipose triglyceride lipase knockout (ATGL(-/-)) mice (model of impaired cardiac function), and 11 rats in which we induced cardiac ischemia. The LV volumes and function were either assessed with parallel short-axis slices covering the full volume of the left ventricle (FV, gold standard) or with various geometrical models [modified Simpson rule (SR), biplane ellipsoid (BP), hemisphere cylinder (HC), single-plane ellipsoid (SP), and modified Teichholz Formula (TF)]. Reproducibility of the different models was tested and results were correlated with the gold standard (FV). All models and the FV data set provided reproducible results for the LV volumes and EF, with interclass correlation coefficients ≥0.87. All models significantly over- or underestimated EF, except for SR. Good correlation was found for all volumes and EF for the SR model compared with the FV data set (R(2) ranged between 0.59-0.95 for all parameters). The HC model and BP model also predicted EF well (R(2) ≥ 0.85), although proved to be less useful for quantitative analysis. The SP and TF models correlated poorly with the FV data set (R(2) ≥ 0.45 for EF and R(2) ≥ 0.29 for EF, respectively). For the reduction in acquisition and postprocessing time, only the SR model proved to be a valuable method for calculating LV volumes, stroke volume, and EF.