Development and construct validation of a parent-proxy quality of life instrument in children with bronchopulmonary dysplasia aged 4-8 years old.

PURPOSE: Children with bronchopulmonary dysplasia often develop complications that affect them well into adult life. Very little is known about how this affects their quality of life, since no sensitive instrument is available to measure health-related quality of life in this population. In this study, a Dutch parent-proxy instrument was developed for this purpose. METHODS: A list of items was generated after literature search and interviews with both parents of patients and clinical experts. Clinically relevant items were selected with the clinical impact method and item analysis. Results of clinical tests to measure complications in children with bronchopulmonary dysplasia were correlated with these items to select the items that show construct validity. Cronbach's alpha was calculated to estimate internal consistency of the items in the final questionnaire. RESULTS: In total, 92 children and their parents and 7 clinicians participated. Of 130 identified items, 47 showed clinical relevance. Spirometry, the Child Behavior Checklist, mean arterial pressure, and body mass index were used to determine construct validity of 33 items. These items were structured within five domains: pulmonary complaints, school functioning, growth and nutrition, exercise and locomotion, emotional functioning and health care concerns. The questionnaire showed excellent internal consistency with Cronbach's alpha of 0.919. CONCLUSION: This study developed a disease-specific parent-proxy instrument to measure health-related quality of life in children with bronchopulmonary dysplasia aged 4-8 years old, the BPD-QoL. All included items show construct validity and internal consistency reliability. Future research should focus on further validation and analysis of responsiveness and reliability.

Changes in Perceived Supervision Quality After Introduction of Competency-Based Orthopedic Residency Training: A National 6-Year Follow-Up Study.

OBJECTIVE: To evaluate the perceived quality of the learning environment, before and after introduction of competency-based postgraduate orthopedic education. DESIGN: From 2009 to 2014, we conducted annual surveys among Dutch orthopedic residents. The validated Dutch Residency Educational Climate Test (D-RECT, 50 items on 11 subscales) was used to assess the quality of the learning environment. Scores range from 1 (poor) to 5 (excellent). SETTING: Dynamic cohort follow-up study. PARTICIPANTS: All Dutch orthopedic residents were surveyed during annual compulsory courses. RESULTS: Over the 6-year period, 641 responses were obtained (response rate 92%). Scores for "supervision" (95% CI for difference 0.06-0.28, p = 0.002) and "coaching and assessment" (95% CI 0.11-0.35, p < 0.001) improved significantly after introduction of competency-based training. There was no significant change in score on the other subscales of the D-RECT. CONCLUSIONS: After the introduction of some of the core components of competency-based postgraduate orthopedic education the perceived quality of "supervision" and "coaching and assessment" improved significantly.

Minimal important change in the pelvic floor distress inventory-20 among women opting for conservative prolapse treatment.

BACKGROUND: The Pelvic Floor Distress Inventory-20 is used to evaluate symptoms and treatment effects in women with pelvic floor disorders. To interpret changes in the scores of this inventory, information is needed about what patients and clinicians perceive as the minimal important (meaningful) change. Although this change in the inventory score has been investigated previously in women who have undergone pelvic floor surgery, the results could not be generalized to women with milder symptoms (ie, lower scores) who often require only conservative treatment. OBJECTIVE: We aimed to estimate the minimal important change in the Pelvic Floor Distress Inventory-20 that was needed to demonstrate clinical improvement in women who qualify for conservative pelvic floor treatment. STUDY DESIGN: The data of 214 women aged ≥55 years were used. All participants were from 2 randomized controlled trials that compared conservative prolapse treatments in primary care in The Netherlands. The degree of prolapse was assessed with the use of the Pelvic Organ Prolapse Quantification system; participants completed the Pelvic Floor Distress Inventory-20 at baseline and at 12 months, with a global perception of improvement question at 12 months. To assess both the patient perspective and the clinical perspective, 2 anchors were assessed: (1) the global perception of improvement was considered the anchor for the patients' perspective, and (2) the difference in the degree of prolapse was considered the anchor for the clinical perspective. Provided that the anchors were correlated by at least 0.3 to the Pelvic Floor Distress Inventory-20 change scores, we estimated the following minimal important changes: (1) the optimal cutoff-point of the receiver operating characteristics curve that discriminates between women with and without improvement in the global perception of improvement scale and (2) the mean Pelvic Floor Distress Inventory-20 change score of participants who improved 1 assessment stage. We then calculated the smallest detectable change to check whether the minimal important change was larger than the measurement error of the questionnaire. RESULTS: Using the global perception of improvement as the anchor, we found a minimal important change for improvement of 13.5 points (95% confidence interval, 6.2-20.9). The Pelvic Organ Prolapse Quantification change scores correlated poorly to the Pelvic Floor Distress Inventory-20 change scores and therefore could not be used as an anchor. The smallest detectable change at the group level was 5.5 points. Thus, the minimal important change was larger than the smallest detectable change at the group level. CONCLUSION: In women with relatively mild pelvic floor symptoms, an improvement of 13.5 points (or a 23% reduction) in the Pelvic Floor Distress Inventory-20 score can be considered clinically relevant. This minimal important change can be used for clinical trial planning and evaluation of treatment effects in women whose condition is considered suitable for conservative treatment.

Diagnostic Accuracy of Fecal Calprotectin for Pediatric Inflammatory Bowel Disease in Primary Care: A Prospective Cohort Study.

PURPOSE: In specialist care, fecal calprotectin (FCal) is a commonly used noninvasive diagnostic test for ruling out inflammatory bowel disease (IBD) in children with chronic gastrointestinal symptoms. The aim of this study was to evaluate the diagnostic accuracy of FCal for IBD in symptomatic children in primary care. METHODS: We studied 2 prospective cohorts of children with chronic diarrhea, recurrent abdominal pain, or both: children initially seen in primary care (primary care cohort) and children referred to specialist care (referred cohort). FCal (index test) was measured at baseline and compared with 1 of the 2 reference standards for IBD: endoscopic assessment or 1-year follow-up. Physicians were blinded to FCal results, and values greater than 50 µg/g feces were considered positive. We determined specificity in the primary care cohort and sensitivity in the referred cohort. RESULTS: None of the 114 children in the primary care cohort ultimately received a diagnosis of IBD. The specificity of FCal in the primary care cohort was 0.87 (95% CI, 0.80-0.92). Among the 90 children in the referred cohort, 17 (19%) ultimately received a diagnosis of IBD. The sensitivity of FCal in the referred cohort was 0.99 (95% CI, 0.81-1.00). CONCLUSIONS: The findings of this study suggest that a positive FCal result in children with chronic gastrointestinal symptoms seen in primary care is not likely to be indicative of IBD. A negative FCal result is likely to be a true negative, which safely rules out IBD in children in whom a primary care physician considers referral to specialist care.

Long-term outcomes of the Bi-Metric proximally hydroxyapatite-coated femoral stem.

PURPOSE: Promising clinical results and survival rates have been reported for the Bi-Metric proximally hydroxyapatite (HA)-coated femoral stem in short- and mid-term studies. In this study we evaluated the long-term survival as well as clinical and radiological results of this stem. METHODS: From 1992 to 1998 we prospectively included 112 consecutive patients who received a total hip arthroplasty (THA) with an uncemented proximally HA-coated Bi-Metric femoral component (Biomet).At 3 months, 1 year and thereafter every 2 to 3 years, patients were clinically and radiologically monitored. Primary endpoint was revision of the stem for any reason. Secondary endpoints were survival of the cup and THA, radiological characteristics and clinical scores (HHS, HOOS, SF-36 and VAS). RESULTS: Median follow-up was 20 (16-22.25) years. Median age at surgery was 52 (22-63) years. At final follow-up, survival analysis showed an all-cause stem survival of 96.8% (95% CI, 93.3-100). Median HHS scores improved from 57 preoperatively to 94 at final follow-up (p<0.001). At final follow-up the median HOOS score was 80 (9-100); median SF-36 score 71 (18-100); median VAS pain score at rest 0 (0-6) and during activity 0 (0-10). CONCLUSIONS: In this prospective cohort study the 20-year survival rate of the Bi-Metric proximally HA-coated femoral stem was excellent.

First experiences with the direct anterior approach in lateral decubitus position: learning curve and 1 year complication rate.

The direct anterior approach (DAA) in supine position for hip arthroplasty has been reported to suffer from high complication rates initially. The DAA with the patient in lateral decubitus position is believed to provide better visibility and especially femoral accessibility with potential fewer complications.The first cohort of total hip prostheses, which were implanted by a single surgeon using DAA in lateral decubitus position more than 1 year ago, was analysed retrospectively.In total 182 hip prostheses (172 patients) were analysed. Three consecutive time periods based on equal number of surgical procedures were compared. The technical complication rate and operating time improved significantly between the 3 consecutive groups. The 1 year infection rate was 0.5% and survival rate of 98.9%.This is the first series of patients that were subjected to a hip replacement based on the direct anterior approach in a lateral decubitus position in which decreasing complication rates suggest the presence of a learning curve in surgeons conducting this type of surgery. Initial complication rate was high but decreased significantly in time and was acceptable certainly in the third group of our cohort. An unacceptable complication rate with the straight uncemented stem forced us to discontinue this configuration after only 7 surgical procedures. Complication, infection and revision rates were acceptable for the all cemented hip replacements using a curved anatomical stem.

Active encouragement of older women with urinary incontinence in primary care to undergo diagnosis and treatment: a matched-pair cluster randomized controlled trial.

OBJECTIVES: The URINO trial investigated the effect of offering treatment to older women with urinary incontinence in the general population, who had not sought help on their own initiative. STUDY DESIGN: In a cluster randomized trial, 14 general practitioners were matched into pairs and randomly allocated to an intervention or a control group. Women aged ≥ 55 years registered in the participating practices were asked about urinary incontinence via a postal questionnaire. Patients in the intervention group were assessed and treated whereas patients in the control group received standard care. MAIN OUTCOME MEASURES: Primary outcome was improvement (yes or no) of the severity of symptoms at 12-month follow-up measured with the Incontinence Severity Index. Secondary outcomes were the number of incontinence episodes per day and quality of life. The primary analysis was on an intention-to-treat basis with multiple imputation of missing data. A logistic regression model with correction for cluster randomization was fitted to estimate odds ratios (ORs). RESULTS: At 12 months, the severity of symptoms had improved in more patients in the intervention group (n166) than in the controls (n184) (OR 1.9; 95% CI 1.1-3.3). Also, the number of patients with fewer episodes of incontinence had increased (OR 2.5; 95% CI 1.5-4.1). No between-group differences in changes in quality of life were apparent (p0.14). CONCLUSIONS: It is recommended to encourage women in the general population aged ≥ 55 years with urinary incontinence to undergo diagnosis and treatment.

Effect of pelvic floor muscle training compared with watchful waiting in older women with symptomatic mild pelvic organ prolapse: randomised controlled trial in primary care.

OBJECTIVE: To compare the effects of pelvic floor muscle training and watchful waiting on pelvic floor symptoms in a primary care population of women aged 55 years and over with symptomatic mild pelvic organ prolapse. DESIGN: Randomised controlled trial. SETTING: Dutch primary care. PARTICIPANTS: Women aged 55 years or over with symptomatic mild prolapse (leading edge above the hymen) were identified by screening. Exclusion criteria were current prolapse treatment or treatment in the previous year, malignancy of pelvic organs, current treatment for another gynaecological disorder, severe/terminal illness, impaired mobility, cognitive impairment, and insufficient command of the Dutch language. INTERVENTIONS: Pelvic floor muscle training versus watchful waiting. MAIN OUTCOME MEASURES: The primary outcome was change in bladder, bowel, and pelvic floor symptoms measured with the Pelvic Floor Distress Inventory-20 (PFDI-20), three months after the start of treatment. Secondary outcomes were changes in condition specific and general quality of life, sexual function, degree of prolapse, pelvic floor muscle function, and patients' perceived change in symptoms. RESULTS: Of the 287 women who were randomised to pelvic floor muscle training (n=145) or watchful waiting (n=142), 250 (87%) completed follow-up. Participants in the intervention group improved by (on average) 9.1 (95% confidence interval 2.8 to 15.4) points more on the PFDI-20 than did participants in the watchful waiting group (P=0.005). Of women in the pelvic floor muscle training group, 57% (82/145) reported an improvement in overall symptoms from the start of the study compared with 13% (18/142) in the watchful waiting group (P<0.001). Other secondary outcomes showed no significant difference between the groups. CONCLUSIONS: Although pelvic floor muscle training led to a significantly greater improvement in PFDI-20 score, the difference between the groups was below the presumed level of clinical relevance (15 points). Nevertheless, 57% of the participants in the intervention group reported an improvement of overall symptoms. More studies are needed to identify factors related to success of pelvic floor muscle training and to investigate long term effects.Trial registration Dutch Trial Register (www.trialregister.nl) identifier: NTR2047.

Sexual function in older women with pelvic floor symptoms: a cross-sectional study in general practice.

BACKGROUND: Pelvic floor symptoms are common and are negatively associated with sexual function which, in turn, is an important aspect of quality of life. The majority of older women with pelvic floor symptoms are treated in general practice but evidence from studies in general practice on the sexual functioning of these women is scarce. AIM: This study examined predictors of sexual inactivity in older women with pelvic floor symptoms in general practice and of sexual functioning in those women who are sexually active. DESIGN AND SETTING: Cross-sectional study in women (aged ≥55 years) from 20 general practices who screened positive on a pelvic floor symptom questionnaire. METHOD: Logistic and linear regression analyses were used to determine predictors of sexual inactivity and sexual functioning (PISQ-12) by assessing their association with patient characteristics, symptoms (PFDI-20) and degree of prolapse (POP-Q). RESULTS: A total of 639 women were included (sexually active n = 393, sexually inactive n = 246). Predictors of sexual inactivity were increasing age (odds ratio [OR] = 1.13; 95% confidence interval [CI] = 1.10 to 1.17) and lower education (OR = 2.31; 95% CI = 1.50 to 3.54; Nagelkerke R(2) = 0.208). In sexually active women, sexual functioning was associated with pelvic floor symptom distress (P<0.001) and pelvic floor surgery (P = 0.018; R(2) = 0.138). CONCLUSION: In older women with pelvic floor symptoms, increasing age and lower educational level are predictors of sexual inactivity. Many of these older women are sexually active and pelvic floor symptom distress is negatively associated with sexual functioning. These results may encourage GPs to ask about sexual problems in women with pelvic floor symptoms.

Skin lesions suspected of malignancy: an increasing burden on general practice.

BACKGROUND: Skin cancer is believed to impose a heavy burden on healthcare services, but the burden of skin lesions suspected of malignancy on primary healthcare has never been evaluated. Therefore the aim of this study was to determine the demand for care in general practice due to these suspected skin lesions (i.e. lesions that are suspected of malignancy by either the patient or the GP). METHODS: Registry study based on data (2001-2010) from the Registration Network Groningen. This is a general practice registration network in the northern part of the Netherlands with an average annual population of approximately 30,000 patients. All patient contacts are coded according to the International Classification of Primary Care (ICPC). Consultations for skin lesions suspected of malignancy were selected according to the assigned ICPC codes. Subsequently, the number of consultations per year and the annual percent change in number of contacts (using the JoinPoint regression program) were calculated and analysed. Additionally, the percentage of patients referred to secondary care or receiving minor surgery within one year after the first contact were calculated. RESULTS: From 2001 onwards we found an annual increase in demand for care due to skin lesions suspected of malignancy of 7.3% (p < 0.01) and in 2010 the benign:malignant ratio was 10:1. In total 13.0% of the patients were referred and after 2006, minor surgery was performed on 31.2% of the patients. Most surgeries and referrals took place within 30 days. CONCLUSIONS: Suspected skin lesions impose an increasing burden on primary healthcare and most likely on healthcare costs as well. General practitioners should therefore be trained in diagnosing skin lesions suspected of malignancy, as a high diagnostic accuracy can save lives in the case of melanoma, and may also prevent unnecessary, costly, excisions and referrals to secondary healthcare.

Challenges in diagnostic accuracy studies in primary care: the fecal calprotectin example.

BACKGROUND: Low disease prevalence and lack of uniform reference standards in primary care induce methodological challenges for investigating the diagnostic accuracy of a test. We present a study design that copes with these methodological challenges and discuss the methodological implications of our choices, using a quality assessment tool for diagnostic accuracy studies (QUADAS-2). DESIGN: The study investigates the diagnostic value of fecal calprotectin for detecting inflammatory bowel disease in children presenting with chronic gastrointestinal symptoms in primary care. It is a prospective cohort study including two cohorts of children: one cohort will be recruited in primary care and the other in secondary/tertiary care. Test results of fecal calprotectin will be compared to one of the two reference standards for inflammatory bowel disease: endoscopy with histopathological examination of mucosal biopsies or assessment of clinical symptoms at 1-year follow-up. DISCUSSION: According to QUADAS-2 the use of two reference standards and the recruitment of patients in two populations may cause differential verification bias and spectrum bias, respectively. The clinical relevance of this potential bias and methods to adjust for this are presented. This study illustrates the importance of awareness of the different kinds of bias that result from choices in the design phase of a diagnostic study in a low prevalence setting. This approach is exemplary for other diagnostic research in primary care.

What is the optimal means of preparing the endometrium in frozen-thawed embryo transfer cycles? A systematic review and meta-analysis.

BACKGROUND Frozen-thawed embryo transfer (FET) enables surplus embryos derived from IVF or IVF-ICSI treatment to be stored and transferred at a later date. In recent years the number of FET cycles performed has increased due to transferring fewer embryos per transfer and improved laboratory techniques. Currently, there is little consensus on the most effective method of endometrium preparation prior to FET. METHODS Using both MEDLINE and EMBASE database a systematic review and meta-analysis of literature was performed. Case-series, case-control studies and articles in languages other than English, Dutch or Spanish were excluded. Those studies comparing clinical and ongoing pregnancy rates as well as live birth rates in (i) true natural cycle FET (NC-FET) versus modified NC-FET, (ii) NC-FET versus artificial cycle FET (AC-FET), (iii) AC-FET versus artificial with GnRH agonist cycle FET and (iv) NC-FET versus artificial with GnRH agonist cycle FET were included. Forest plots were constructed and relative risks or odds ratios were calculated. RESULTS A total of 43 publications were selected for critical appraisal and 20 articles were included in the final review. For all comparisons, no differences in the clinical pregnancy rate, ongoing pregnancy rate or live birth rate could be found. Based on information provided in the articles no conclusions could be drawn with regard to cancellation rates. CONCLUSIONS Based on the current literature it is not possible to identify one method of endometrium preparation in FET as being more effective than another. Therefore, all of the current methods of endometrial preparation appear to be equally successful in terms of ongoing pregnancy rate. However, in some comparisons predominantly retrospective studies were included leaving these comparisons subject to selection and publication bias. Also patients' preferences as well as cost-efficiency were not addressed in any of the included studies. Therefore, prospective randomized studies addressing these issues are needed.

Physical activity and risk of lymphoma: a meta-analysis.

BACKGROUND: Physical activity has a protective effect on some types of cancer. The aim of the present meta-analysis was to explore the literature on the association between physical activity and risk of lymphoma. METHODS: A meta-analysis was conducted for cohort and case-control studies examining the association between self-reported physical activity and risk of lymphoma. Depending on statistical heterogeneity, a random or fixed effects model was used to estimate the summary OR and corresponding 95% confidence interval (CI). RESULTS: Seven case-control studies and 5 cohort studies were included. When data from both study designs were combined, no significant influence of physical activity on risk of lymphoma was found (pooled OR = 0.90; 95% CI: 0.79-1.02; P = 0.10). Subgroup analysis revealed a significant protective influence of physical activity on risk of lymphoma in case-control studies (pooled OR = 0.81; 95% CI: 0.68-0.96; P = 0.02). In contrast, cohort studies, which have a higher level of evidence than case-control studies, confirm the results of the primary meta-analysis (pooled OR = 1.02; 95% CI: 0.88-1.19; P = 0.76). A subsequent subgroup analysis found no significant differences between results for Hodgkin lymphoma and non-Hodgkin lymphoma (χ(2) = 0.16; P = 0.69), nor between results for recreational and occupational activities (χ(2) = 1.01; P = 0.31). CONCLUSIONS: Epidemiologic research indicates no significant influence of physical activity on risk of lymphoma. IMPACT: Future research should examine the association between sedentary behavior and risk of lymphoma and investigate the dose-response and timing effect of physical activity on risk of lymphoma.

Impact of the European Randomized Study of Screening for Prostate Cancer (ERSPC) on prostate-specific antigen (PSA) testing by Dutch general practitioners.

OBJECTIVE: To determine the impact of the European Randomized Study of Screening for Prostate Cancer (ERSPC) publication in 2009 on prostate-specific antigen (PSA) level testing by Dutch general practitioners (GPs) in men aged ≥40 years. MATERIALS AND METHODS: Retrospective study with a Dutch insurance company database (containing PSA test claims) and a large district hospital-laboratory database (containing PSA-test results). The difference in primary PSA-testing rate as well as follow-up testing before and after the ERSPC was tested using the chi-square test with statistical significance at P < 0.05. RESULTS: Decline in PSA tests 4 months after ERSPC publication, especially for men aged ≥60 years. Primary testing as well as follow-up testing decreased, both for PSA levels of <4 ng/mL as well as for PSA levels of 4-10 ng/mL. Follow-up testing after a PSA level result of >10 ng/mL moderately increased (P = 0.171). Referral to a urologist after a PSA level result of >4 ng/mL decreased slightly after the ERSPC publication (P = 0.044). CONCLUSIONS: After the ERSPC publication primary PSA testing as well as follow-up testing decreased. Follow-up testing seemed not to be adequate after an abnormal PSA result. The reasons for this remain unclear.

Systematic screening for urinary incontinence in older women: who could benefit from it?

OBJECTIVE: To identify women who are suffering from urinary incontinence but do not consult a physician and to identify reasons for this. DESIGN: Survey study as part of a randomized controlled trial that investigates the effects of a standardized assessment and evidence-based treatment on urinary incontinence in older women, the URINO project. SETTING: Female patients from general practices in the Northern part of the Netherlands. PATIENTS: A total of 225 women of 55 years and older suffering from urinary incontinence. MAIN OUTCOME MEASURES: Number of patients with urinary incontinence who are not registered by their GP as suffering from this, factors associated with help-seeking behaviour, and reasons for not seeking help. RESULTS: Of the 225 patients, 143 (64%) were not registered by their GP as suffering from urinary incontinence. These women were more often younger and had lower levels of distress due to their urogynaecological symptoms. The most common reason for not consulting a GP was that patients considered their symptoms not to be serious enough. CONCLUSION: The prevalence of older women with urinary incontinence who do not seek help is high. Help-seeking behaviour is associated with increasing age and higher levels of distress caused by the symptoms. Younger patients more often hesitate to consult their GP if they perceive their symptoms to be relatively mild.

Minimally invasive versus classic procedures in total hip arthroplasty: a double-blind randomized controlled trial.

BACKGROUND: For total hip arthroplasty (THA), minimally invasive surgery (MIS) uses a smaller incision and less muscle dissection than the classic approach (CLASS), and may lead to faster rehabilitation. QUESTIONS/PURPOSES: Does minimally invasive hip arthroplasty result in superior clinical outcomes? PATIENTS AND METHODS: In this double-blind randomized controlled trial, 120 consecutive primary noncemented THAs in 120 patients were assigned to one of two groups (MIS or CLASS). The randomization sequence was stratified for two groups of surgeons, ie, those using a posterolateral approach (PL-CLASS or PL-MIS) and those using an anterolateral approach (AL-CLASS or AL-MIS). Length of the incisions was 18 cm for the CLASS procedures. MIS incisions were extended at the skin level to 18 cm at the end of the procedure. The primary end point was the Harris hip score (HHS) at 6 weeks postoperatively. Patient-centered questionnaires were obtained preoperatively and after 6 weeks and 1 year. RESULTS: For the patients in the MIS group (average 7.8 cm incision length), statistically significant increased mean HHSs were seen compared with the CLASS group at 6 weeks and 1 year. This difference was small and mainly caused by the favorable results of the PL-MIS. In the MIS group, surgical time was longer. A learning curve was observed based on operation time and complication rate. Although not statistically significant, the perioperative complication rate was rather high in the (anterolateral) MIS group. CONCLUSIONS: The minimal invasive approach in THA did not show a clinically relevant superior outcome in the first postoperative year. LEVEL OF EVIDENCE: Level I, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Factors associated with reduced early survival in the Oxford phase III medial unicompartment knee replacement.

The aim of this study was to determine the prognostic value of preoperative patellofemoral osteoarthritis, BMI and age for implant survival of unicompartmental knee arthroplasty (UKA) performed in patients meeting strict admission criteria. The data and radiographs of 437 unilateral Oxford phase III procedures (Biomet, Bridgend, UK) were analysed. All procedures were carried out or supervised by 13 specialised knee surgeons in three different hospitals. The study group comprised 437 patients with a median follow of 2.6 years (0.1-7.9). The cumulative standard case survival rate at 5 years, when there were still 101 patients at risk, was 84.7% (CI-95%: 80.1-89.3%). Young age (<60 years) was associated with a 2.2-fold increased adjusted risk of revision (CI: 1.08-4.43; p=0.03). The preoperative presence of radiological features of patellofemoral osteoarthritis was associated with a 0.3-fold reduced adjusted risk of revision (CI: 0.11-0.89; p=0.03). BMI>30 kg/m(2), gender, the surgeon performing the operation (either as an individual or categorised by annual surgical UKA caseload, i.e., more or less than 10 UKAs) and the hospital in which surgery took place did not predict implant survival of UKA. We conclude that young patients (<60 years) experience an increased early risk of revision for UKA when compared to older patients (>60 years). Obesity (BMI>30 kg/m(2)) and preoperative patellofemoral osteoarthritis are not associated with a decreased implant survival and therefore should not be considered risk factors in this context.

Antioxidant role of plasma carotenoids in bronchopulmonary dysplasia in preterm infants.

OBJECTIVES: Oxidative stress is implicated in the pathogenesis of bronchopulmonary dysplasia (BPD) and consequently, it might be theorized that sufficient antioxidant defenses are needed to prevent BPD. We hypothesized that, except for vitamins E and A, carotenoids may be important in this defense. Carotenoids are present in human milk; however, they are not added to parenteral nutrition, the main food source of preterm infants in the first week of life. AIM: To evaluate prospectively the role of carotenoids in BPD in a cohort of preterm infants. METHODS: The plasma concentrations of F(2alpha)-isoprostane, alpha- and beta-carotene, lycopene, lutein, vitamin A, and the vitamin E/cholesterol ratio were studied at days 1, 3, and 7 in a cohort of 109 preterm infants, of whom 19 had BPD. RESULTS: When comparing the BPD and control group, infants in the BPD group were younger (p<0.001) and beta-carotene (day 7, p<0.01) and vitamin A concentrations were lower (days 3 and 7, p<0.001). Lycopene, lutein, alpha-carotene, vitamin E, and F(2alpha)-isoprostane concentrations did not differ between groups. CONCLUSIONS: Plasma beta-carotene and vitamin A concentrations are lower in BPD infants which may result in a reduction of their antioxidant protection.