Fracture incidence and fracture-related mortality decreased with decreases in population mobility during the early days of the COVID-19 pandemic: an epidemiological study.

INTRODUCTION: We investigated the impact of coronavirus disease 2019 (COVID-19) social distancing measures on fracture incidence and fracture-related mortality, as well as associations with population mobility. METHODS: In total, 47 186 fractures were analysed across 43 public hospitals from 22 November 2016 to 26 March 2020. Considering the smartphone penetration of 91.5% in the study population, population mobility was quantified using Apple Inc's Mobility Trends Report, an index of internet location services usage volume. Fracture incidences were compared between the first 62 days of social distancing measures and corresponding preceding epochs. Primary outcomes were associations between fracture incidence and population mobility, quantified by incidence rate ratios (IRRs). Secondary outcomes included fracture-related mortality rate (death within 30 days of fracture) and associations between emergency orthopaedic healthcare demand and population mobility. RESULTS: Overall, 1748 fewer fractures than projected were observed during the first 62 days of COVID-19 social distancing (fracture incidence: 321.9 vs 459.1 per 100 000 person-years, P<0.001); the relative risk was 0.690, compared with mean incidences during the same period in the previous 3 years. Population mobility exhibited significant associations with fracture incidence (IRR=1.0055, P<0.001), fracture-related emergency department attendances (IRR=1.0076, P<0.001), hospital admissions (IRR=1.0054, P<0.001), and subsequent surgery (IRR=1.0041, P<0.001). Fracture-related mortality decreased from 4.70 (in prior years) to 3.22 deaths per 100 000 person-years during the COVID-19 social distancing period (P<0.001). CONCLUSION: Fracture incidence and fracture-related mortality decreased during the early days of the COVID-19 pandemic; they demonstrated significant temporal associations with daily population mobility, presumably as a collateral effect of social distancing measures.

Systematic review and meta-analysis of birth weight and PFNA exposures.

We used a systematic review that included risk of bias and study sensitivity analysis to identify 34 studies examining changes in birth weight (BWT) in relation to PFNA biomarker measures (e.g., maternal serum/plasma or umbilical cord samples). We fit a random effects model of the overall pooled estimate and stratified estimates based on sample timing and overall study confidence. We conducted a meta-regression to further examine the impact of gestational age at biomarker sample timing. We detected a -32.9 g (95%CI: -47.0, -18.7) mean BWT deficit per each ln PFNA increase from 27 included studies. We did not detect evidence of publication bias (pE = 0.30) or between-study heterogeneity in the summary estimate (pQ = 0.05; I2 = 36%). The twelve high confidence studies yielded a smaller pooled effect estimate (ß = -28.0 g; 95%CI: -49.0, -6.9) than the ten medium (ß = -39.0 g; 95%CI: -61.8, -16.3) or four low (ß = -36.9 g; 95%CI: -82.9, 9.1) confidence studies. The stratum-specific results based on earlier pregnancy sampling periods in 11 studies showed smaller deficits (ß = -22.0 g; 95%CI: -40.1, -4.0) compared to 10 mid- and late-pregnancy (ß = -44.2 g; 95%CI: -64.8, -23.5) studies and six post-partum studies (ß = -42.9 g; 95%CI: -88.0, 2.2). Using estimates of the specific gestational week of sampling, the meta-regression showed results consistent with the categorical sample analysis, in that as gestational age at sampling time increases across these studies, the summary effect estimate of a mean BWT deficit got larger. Overall, we detected mean BWT deficits for PFNA that were larger and more consistent across studies than previous PFAS meta-analyses. Compared to studies with later sampling, BWT deficits were smaller but remained sizeable for even the earliest sampling periods. Contrary to earlier meta-analyses for PFOA and PFOS, BWT deficits that were detected across all strata did not appear to be fully explained by potential bias due to pregnancy hemodynamics from sampling timing differences.

Diagnostic stewardship programme for urine culture: impact on antimicrobial prescription in a multi-centre cohort.

BACKGROUND: Restricting urine culture to patients with genuine urinary tract infection (UTI) reduces excessive antimicrobial prescription for asymptomatic bacteriuria. AIM: To evaluate the impact of urine culture diagnostic stewardship on antimicrobial consumption. METHODS: This quasi-study involved two general hospitals and 10 community clinics. In the pre-intervention (control) phase (25th November 2018-2nd February 2019), microscopy and culture results of all urine specimens were reported. In the post-intervention (study) phase (25th November 2019-2nd February 2020), urine cultures were processed and reported only if at least one of the following criteria were met: presence of white blood cells or bacteria on microscopy; patient from obstetrics, urology, paediatrics, oncology or renal transplant ward; specimen labelled as 'pregnancy', 'urological procedure', 'renal transplant' or 'neutropenic'; and ureteric, nephrostomy or suprapubic urine. For urine samples that did not fulfil these criteria, the microscopy results and a rejection comment were reported. FINDINGS: In total, 12,282 urine specimens were included in the intervention phase. Of these, 4757 (38.7%) specimens did not fulfil the screening criteria, and the microscopy result and a rejection comment were reported. One hundred and sixty-three (3.4%) of these non-reported urine cultures yielded significant bacterial growth, and the majority were Escherichia coli (N=58, 35.6%). Diagnostic stewardship was independently associated with lower antimicrobial consumption [adjusted odds ratio 0.76, 95% confidence interval (CI) 0.70-0.83, P<0.001] on multi-variable logistic regression across all healthcare settings. Diagnostic stewardship had no effect on patient mortality (adjusted hazard ratio=0.95, 95% CI 0.89-1.01, P=0.08). No patients with unreported urine culture developed bacteraemia from untreated UTI. CONCLUSION: Diagnostic stewardship of urine culture safely reduced excessive antimicrobial prescription for asymptomatic bacteriuria.

Dual gold and photoredox catalysed C-H activation of arenes for aryl-aryl cross couplings.

A mild and fully catalytic aryl-aryl cross coupling via gold-catalysed C-H activation has been achieved by merging gold and photoredox catalysis. The procedure is free of stoichiometric oxidants and additives, which were previously required in gold-catalysed C-H activation reactions. Exploiting dual gold and photoredox catalysis confers regioselectivity via the crucial gold-catalysed C-H activation step, which is not present in the unselective photocatalysis-only counterpart.

Prevalence and impact of urinary incontinence in men with chronic obstructive pulmonary disease: a questionnaire survey.

OBJECTIVES: To identify urinary incontinence and its impact on men with stable chronic obstructive pulmonary disease (COPD) and men without lung disease. DESIGN: Prospective questionnaire study. SETTING: Outpatients attending a public metropolitan hospital. PARTICIPANTS: Men with COPD (n=49) and age-matched men without lung disease (n=36). INTERVENTIONS: Validated questionnaires to identify the prevalence and impact of urinary incontinence. MAIN OUTCOME MEASURES: Prevalence of urinary incontinence and relationship with disease-specific factors, and relationship of urinary incontinence with anxiety and depression. RESULTS: The prevalence of urinary incontinence was higher in men with COPD (n=19/49) compared with men without lung disease (n=6/36; P=0.027). In men with COPD, symptoms of urgency were more prevalent in men with urinary incontinence (P=0.005), but this was not evident in men without lung disease (P=0.101). Only men with COPD reported symptoms of urgency associated with dyspnoea, and this did not vary between men with and without urinary incontinence (P=0.138). In men with COPD, forced expiratory volume in 1 second (FEV1) was lower in those with urinary incontinence compared with those without urinary incontinence {mean 38 [standard deviation (SD) 14] % predicted vs 61 (SD 24) % predicted; P=0.002}. The impact of urinary incontinence did not differ between the two groups (P=0.333). CONCLUSIONS: Incontinence is more prevalent in men with COPD than in men without lung disease. The prevalence of urinary incontinence increases with greater disease severity, as reflected by lower FEV1. Screening for urinary incontinence should be considered in men with COPD and compromised lung function.

Significance of Time-Zero Biopsy for Graft Renal Function After Deceased Donor Kidney Transplantation.

BACKGROUND: Donor organ quality from deceased donors affects graft survival after kidney transplantation. This study was performed to identify clinico-histological factors that affect early graft outcome, using time-zero biopsies of deceased donors. METHODS: Between December 2006 and July 2011, 135 recipients of deceased donor kidneys were included, and data concerning donor and recipient-related clinical characteristics and histological findings of time-zero biopsies categorized by use of the Banff 07 scoring system were included in the analysis. Mean donor age was 44.3 ± 12.3 years. Mean terminal serum creatinine level and cold ischemic time were 1.50 ± 0.96 mg/dL and 349 ± 166 minutes. Mean follow-up time after transplantation was 37 ± 16 months, and all recipients were followed for at least 1 year. RESULTS: Global glomerulosclerosis (38.5%), tubular atrophy (37.8%), arteriolar hyaline thickening (25.9%), interstitial fibrosis (23%), vascular fibrous intimal thickening (21.5%), and interstitial inflammation (20%) were the major pathologic findings of time-zero biopsies. The majority of pathologic scores were of mild degree. Among histological findings, arteriolar hyaline thickening and interstitial fibrosis were only significantly associated with early post-transplant renal function in multivariate analyses. CONCLUSIONS: Considerations of clinico-histological findings were found to be valuable for predicting early graft outcome after deceased donor kidney transplantation.

Enantioselective oxidative boron Heck reactions.

This review highlights the use of the oxidative boron Heck reaction in enantioselective Heck-type couplings. The enantioselective oxidative boron Heck reaction overcomes several limitations of the traditional Pd(0)-catalysed Heck coupling and has subsequently allowed for intermolecular couplings of challenging systems such as cyclic enones, acyclic alkenes, and even site selectively on remote alkenes.

Oxidative Heck desymmetrisation of 2,2-disubstituted cyclopentene-1,3-diones.

Oxidative Heck couplings have been successfully developed for 2,2-disubstituted cyclopentene-1,3-diones. The direct coupling onto the 2,2-disubstituted cyclopentene-1,3-dione core provides a novel expedient way of enantioselectively desymmetrising all-carbon quaternary centres.

Dehydrative thiolation of allenols: indium vs gold catalysis.

Intermolecular additions of thiols to allenols via formal S(N)2' selectivity to produce functionalized dienes are described. Although this dehydrative reaction was initially developed using gold(I) catalysis, indium(III) proves to be a far superior catalyst in terms of selectivity and substrate scope.

MicroRNA-302 induces proliferation and inhibits oxidant-induced cell death in human adipose tissue-derived mesenchymal stem cells.

Mesenchymal stem cells (MSCs) are a heterogeneous population of cells that proliferate in vitro as plastic-adherent cells, have a fibroblast-like morphology, form colonies in vitro and can differentiate into bone, cartilage and fat cells. The abundance, ease and repeatable access to subcutaneous adipose tissue and the simple isolation procedures provide clear advantages for the use of human adipose tissue-derived mesenchymal stem cells (hASDCs) in clinical applications. We screened microRNAs (miRNAs) that affected the proliferation and survival of hADSCs. Transfection of miR-302d mimic increased cell proliferation and protected cells from oxidant-induced cell death in hADSCs, which was supported by flow-cytometric analysis. miR-302d did not affect the expression of Bcl-2 family members or anti-oxidant molecules. The Nrf2-Keap1 system, which is one of the major mechanisms for the cellular defense against oxidative stress, was not altered by transfection of miR-302d mimic. To identify the target of the miR-302d actions on proliferation and survival of hADSCs, a microarray analysis was performed using miR-302d-overexpressing hADSCs. Real-time PCR analysis showed that transfection of miR-302d mimic inhibited the CDKN1A and CCL5 expression. Downregulation of CDKN1A with a specific siRNA mimicked the effect of miR-302d on hADSCs proliferation, but did not affect miR-302d-induced cell survival. Downregulation of CCL5 protected oxidant-induced cell death as miR-302d, inhibited oxidant-induced reactive oxygen species (ROS) generation and the addition of recombinant CCL5 inhibited the protective action of miR-302d on oxidant-induced cell death. This study indicates that miR-302 controls proliferation and cell survival of hADSCs through different targets and that this miRNA can be used to enhance the therapeutic efficacy of hADSCs transplantation in vivo.

Minimal important difference in field walking tests in non-cystic fibrosis bronchiectasis following exercise training.

BACKGROUND: The 6-min walk distance (6MWD) and incremental shuttle walk distance (ISWD) are clinically meaningful measures of exercise capacity in people with non-cystic fibrosis (CF) bronchiectasis, but the change in walking distance which constitutes clinical benefit is undefined. This study aimed to determine the minimal important difference for the 6MWD and ISWD in non-CF bronchiectasis. METHODS: Thirty-seven participants with mean FEV1 70% predicted completed both field walking tests before and after an 8-week exercise program. The minimal important difference was calculated using a distribution-based and anchor-based method, with the global rating of change scale used. RESULTS: The mean change in 6MWD in participants who reported themselves to be unchanged was 10 m, compared to 36 m (small change) and 45 m (substantial change) (p = 0.01). For the ISWD, the mean change in participants who reported themselves to be unchanged was 33 m, compared to 54 m (small change) and 73 m (substantial change) (p = 0.04). The anchor-based method defined the minimal important difference for 6MWD as 24.5 m (AUC 0.76, 95% CI 0.61-0.91) and for ISWD as 35 m (AUC 0.88, 95% CI 0.73-0.99), based on participant's global rating of change. The distribution-based method indicated a value of 22.3 m for the 6MWD and 37 m for the ISWD. There was excellent agreement between the two methods for the 6MWD (kappa = 0.91) and the ISWD (kappa = 0.92). CONCLUSIONS: Small changes in 6MWD and ISWD may represent clinically important benefits in people with non-CF bronchiectasis. These data are likely to assist in the interpretation of change in exercise capacity following intervention.

Glioma: Application of histogram analysis of pharmacokinetic parameters from T1-weighted dynamic contrast-enhanced MR imaging to tumor grading.

BACKGROUND AND PURPOSE: The usefulness of pharmacokinetic parameters for glioma grading has been reported based on the perfusion data from parts of entire-tumor volumes. However, the perfusion values may not reflect the entire-tumor characteristics. Our aim was to investigate the feasibility of glioma grading by using histogram analyses of pharmacokinetic parameters including the volume transfer constant, extravascular extracellular space volume per unit volume of tissue, and blood plasma volume per unit volume of tissue from T1-weighted dynamic contrast-enhanced perfusion MR imaging. MATERIALS AND METHODS: Twenty-eight patients (14 men, 14 women; mean age, 49.75 years; age range, 25-72 years) with histopathologically confirmed gliomas (World Health Organization grade II, n = 7; grade III, n = 8; grade IV, n = 13) were examined before surgery or biopsy with conventional MR imaging and T1-weighted dynamic contrast-enhanced perfusion MR imaging at 3T. Volume transfer constant, extravascular extracellular space volume per unit volume of tissue, and blood plasma volume per unit volume of tissue were calculated from the entire-tumor volume. Histogram analyses from these parameters were correlated with glioma grades. The parameters with the best percentile from cumulative histograms were identified by analysis of the area under the curve of the receiver operating characteristic analysis and were compared by using multivariable stepwise logistic regression analysis for distinguishing high- from low-grade gliomas. RESULTS: All parametric values increased with increasing glioma grade. There were significant differences among the 3 grades in all parameters (P < .01). For the differentiation of high- and low-grade gliomas, the highest area under the curve values were found at the 98th percentile of the volume transfer constant (area under the curve, 0.912; cutoff value, 0.277), the 90th percentile of extravascular extracellular space volume per unit volume of tissue (area under the curve, 0.939; cutoff value, 19.70), and the 84th percentile of blood plasma volume per unit volume of tissue (area under the curve, 0.769; cutoff value, 11.71). The 98th percentile volume transfer constant value was the only variable that could be used to independently differentiate high- and low-grade gliomas in multivariable stepwise logistic regression analysis. CONCLUSIONS: Histogram analysis of pharmacokinetic parameters from whole-tumor volume data can be a useful method for glioma grading. The 98th percentile value of the volume transfer constant was the most significant measure.

The impact of time-zero biopsy on early graft outcomes after living donor kidney transplantation.

BACKGROUND: In contrast with deceased donor transplantation, the clinical significance of pathologic findings in time-zero biopsies after living donor kidney transplantation are rarely reported, due to the expectation that histologic findings and renal function are normal. The aim of this study was to identify subclinical pathologic findings in living donors and examine the effect on early graft renal function. METHODS: Between December 2006 and July 2011, 146 living-donor kidney transplant recipients were enrolled in this study. We retrospectively analyzed donor and recipient-related clinical parameters, and post-transplant 6 months and 1 year estimated glomerular filtration rate (eGFR) as early graft renal function. Time-zero biopsies were evaluated using the 2007 Banff criteria. RESULTS: Most abnormal histologic findings were of mild degree as determined by Banff scores. Global glomerulosclerosis (GS, 35.6%), tubular atrophy (CT, 36.3%), interstitial fibrosis (CI, 20.5%), vascular fibrous intimal thickening (CV, 4.1%), arteriolar hyaline thickening (AH, 14.4%), interstitial inflammation (I, 3.4%) were pathologic findings in time-zero biopsies. The univariate analysis revealed that donor age and gender were significantly associated with eGFR at post-transplant 6 months and at 1 year (P < .05). Furthermore, GS and CT were significantly associated with early graft renal function (P < .05). However, multivariate linear regression analysis showed only donor age was significantly associated with early graft renal function (P = .001). CONCLUSION: A mild degree of subclinical, pathologic findings on time-zero biopsy did not affect early graft renal function in living-donor kidney transplantation.

Graft function measured by transient elastography in living donor liver transplantation: preliminary.

INTRODUCTION: Liver stiffness measurements (LSMs) using transient elastography (TE) provide a noninvasive means to assess liver fibrosis that correlate with hepatic cholestasis. However, few studies have examined the correlation of TE to obtain LSMs with perioperative clinical and laboratory parameters in living donor liver transplantation (LDLT). PATIENTS AND METHODS: We retrospectively reviewed forty-eight subjects who underwent LDLT between November 2010 and October 2012. All donors and recipients underwent TE, abdominal computed tomography (CT), and biochemical tests within 1 month before and at 1 week after transplantation. Using a cut-off LSM of 7.5 kPa, which we arbitrarily assigned to be indicative of significant fibrosis, we divided our study population into ≤7.5 kPa (group L; n = 15, 31.3%) versus >7.5 kPa; (group H; n = 33, 68.8%). RESULTS: Pretransplantation serum total bilirubin, international normalized ratio, and Model for End-stage Liver Disease scores of recipients were significantly higher in group H than group L. Regarding the pretransplantation donor characteristics, the graft-recipient weight ratio was significantly smaller among those in group H (P = .039). In addition, the post-transplantation 1-week serum total bilirubin level was significantly higher in group H (2.3 mg/dL versus 1.2 mg/dL, P = .015), although neither biliary complications norhepatic congestion was identified by abdominal CT. Among the 1-week post-transplantation laboratory findings, only total bilirubin positively correlated with LSM (P = .044). CONCLUSIONS: This pilot study suggested that a high LSM after LDLT suggests intrahepatic cholestasis and portal hypercirculation in the graft, irrespective of liver fibrosis, outflow obstruction, or biliary obstruction.

Differentiation of recurrent tumor and posttreatment changes in head and neck squamous cell carcinoma: application of high b-value diffusion-weighted imaging.

BACKGROUND AND PURPOSE: High b-value DWI has been expected to have an additional diagnostic role and demonstrated some promising results in head and neck cancer. The aim of this study was to evaluate the diagnostic performance of DWI at a high b-value (b=2000 s/mm(2)) compared with a standard b-value (b=1000 s/mm(2)) and the ratio of ADC values of high and standard b-values for their ability to differentiate between recurrent tumor and posttreatment changes after the treatment of head and neck squamous cell carcinoma. MATERIALS AND METHODS: A total of 33 patients diagnosed with head and neck squamous cell carcinoma were enrolled in the present study; all had contrast-enhancing lesions on follow-up MR imaging. All patients underwent single-shot echo-planar DWI at b=1000 s/mm(2) and b=2000 s/mm(2), and corresponding ADC maps were generated (ADC1000 and ADC2000, respectively). The mean ADC1000, ADC2000, and ADCratio (ADCratio = ADC2000/ADC1000 × 100) values were evaluated within a manually placed ROI with contrast-enhanced T1-weighted images as references. For the statistical analysis, we performed a Student t test and multivariate logistic regression. RESULTS: The mean ADC1000 in recurrent tumor was significantly lower than that in posttreatment changes (P < .001), whereas the mean ADC2000 resulted in no significant difference (P = .365). The mean ADCratio was significantly higher in recurrent tumor than that in posttreatment changes (73.5 ± 7.2% vs 56.9 ± 8.8%, respectively; P < .001). Multivariate logistic regression analysis revealed that the ADCratio was the only independently differentiating variable (P = .024). The sensitivity, specificity, and accuracy of ADCratio were 95.0%, 69.2%, and 84.8%, respectively, by use of the optimal cutoff value of 62.6%. CONCLUSIONS: We suggest that the ADCratio calculated from the ADC1000 and ADC2000 is a promising value for the differentiation of recurrent tumor and posttreatment changes in head and neck squamous cell carcinoma.

Prediction of invasive candidal infection in critically ill patients with severe acute pancreatitis.

INTRODUCTION: Patients with severe acute pancreatitis are at risk of candidal infections carrying the potential risk of an increase in mortality. Since early diagnosis is problematic, several clinical risk scores have been developed to identify patients at risk. Such patients may benefit from prophylactic antifungal therapy while those patients who have a low risk of infection may not benefit and may be harmed. The aim of this study was to assess the validity and discrimination of existing risk scores for invasive candidal infections in patients with severe acute pancreatitis. METHODS: Patients admitted with severe acute pancreatitis to the intensive care unit were analysed. Outcomes and risk factors of admissions with and without candidal infection were compared. Accuracy and discrimination of three existing risk scores for the development of invasive candidal infection (Candida score, Candida Colonisation Index Score and the Invasive Candidiasis Score) were assessed. RESULTS: A total of 101 patients were identified from 2003 to 2011 and 18 (17.8%) of these developed candidal infection. Thirty patients died, giving an overall hospital mortality of 29.7%. Hospital mortality was significantly higher in patients with candidal infection (55.6% compared to 24.1%, P=0.02). Candida colonisation was associated with subsequent candidal infection on multivariate analysis. The Candida Colonisation Index Score was the most accurate test, with specificity of 0.79 (95% confidence interval [CI] 0.68 to 0.88), sensitivity of 0.67 (95% CI 0.41 to 0.87), negative predictive value of 0.91 (95% CI 0.82 to 0.97) and a positive likelihood ratio of 3.2 (95% CI 1.9 to 5.5). The Candida Colonisation Index Score showed the best discrimination with area under the receiver operating characteristic curve of 0.79 (95% CI 0.69 to 0.87). CONCLUSIONS: In this study the Candida Colonisation Index Score was the most accurate and discriminative test at identifying which patients with severe acute pancreatitis are at risk of developing candidal infection. However its low sensitivity may limit its clinical usefulness.

Effects of pulmonary rehabilitation in bronchiectasis: A retrospective study.

There is limited information about the benefits of pulmonary rehabilitation (PR) in patients with bronchiectasis. This study aimed to evaluate the effects of an out-patient PR program in patients with a primary diagnosis of bronchiectasis and to compare them with a matched COPD group who completed the same PR program. A retrospective review was conducted of patients with bronchiectasis or COPD who completed 6 to 8 weeks of PR at two tertiary institutions. The outcome measures were the 6-minute walk distance (6MWD) and Chronic Respiratory Disease Questionnaire (CRQ). Ninety-five patients with bronchiectasis completed the PR (48 male; FEV(1) 63 [24] % predicted; age 67 [10] years). Significant improvements in 6MWD (mean change 53.4 m, 95% CI 45.0 to 61.7) and CRQ total score (mean change 14.0 units, 95% CI 11.3 to 16.7) were observed immediately following PR. In patients with complete follow-up (n = 37), these improvements remained significantly higher than baseline at 12 months (20.5 m, 95% CI 1.4 to 39.5 for 6MWD; 12.1 points, 95% CI 5.7 to 18.4 for CRQ total score). The time trend and changes in the 6MWD and CRQ scores were not significantly different between the bronchiectasis and the COPD groups (all p > 0.05). This study supports the inclusion of patients with bronchiectasis in existing PR programs. Further prospective RCTs are warranted to substantiate these findings.

The six-minute walk test: a useful metric for the cardiopulmonary patient.

Measurement of exercise capacity is an integral element in assessment of patients with cardiopulmonary disease. The 6-min walk test (6MWT) provides information regarding functional capacity, response to therapy and prognosis across a range of chronic cardiopulmonary conditions. A distance less than 350 m is associated with increased mortality in chronic obstructive pulmonary disease, chronic heart failure and pulmonary arterial hypertension. Desaturation during a 6MWT is an important prognostic indicator for patients with interstitial lung disease. The 6MWT is sensitive to commonly used therapies in chronic obstructive pulmonary disease such as pulmonary rehabilitation, oxygen, long-term use of inhaled corticosteroids and lung volume reduction surgery. However, it appears less reliable to detect changes in clinical status associated with medical therapies for heart failure. A change in walking distance of more than 50 m is clinically significant in most disease states. When interpreting the results of a 6MWT, consideration should be given to choice of predictive values and the methods by which the test was carried out.

Clinical determinants of the 6-Minute Walk Test in bronchiectasis.

BACKGROUND: The 6-Minute Walk Test (6MWT) is a widely used measurement of functional exercise capacity in chronic lung disease. While exercise intolerance has been identified in patients with bronchiectasis, the clinical determinants of the 6MWT in this population have not been examined. The aim of this study was to 1) establish the relationship between the 6-Minute Walk Distance (6MWD), disease severity and Health-Related Quality of Life (HRQOL) and 2) identify predictors of exercise tolerance in adults with bronchiectasis. METHODS: The 6MWT was performed in 27 patients with bronchiectasis (mean [SD] FEV(1) 73.9% predicted [23.4]). Disease severity was assessed using spirometry and HRCT scoring while HRQOL was evaluated using the St George's Respiratory Questionnaire (SGRQ) and the Short-Form 36 (SF-36). The relationships were evaluated using correlation and multiple regression. RESULTS: The 6MWD correlated positively with FVC (r=0.52, p<0.01), generations of bronchopulmonary divisions (r(s)=0.38, p<0.05) and SF-36 physical summary (r=0.71, p<0.001) while a negative correlation was observed between all domains of the SGRQ (all correlations r>0.5, p<0.001). Multiple regression analysis indicated that the SGRQ activity, symptom scores and generations of bronchial divisions involved were identified as independent predictors of the 6MWD, explaining 76% of the variance. CONCLUSIONS: Measures of HRQOL demonstrated a stronger association with the 6MWD compared to physiological measures of disease severity in patients with predominantly mild to moderate bronchiectasis.