Results of the First U.S. FDA-Approved Hip Resurfacing Device at 10-Year Follow-up.

BACKGROUND: The BIRMINGHAM HIP Resurfacing (BHR) system is a metal-on-metal hip implant system approved by the U.S. Food and Drug Administration in 2006. The approval required a multicenter, prospective, post-market-approval study. Our purpose is to report the current results at 10 years of follow-up. METHODS: Between October 2006 and December 2009, 280 primary BHR procedures were performed at 5 sites. Outcome measures included Kaplan-Meier survivorship, reasons for revision, radiographic component stability and osteolysis, Harris hip scores, and metal levels including cobalt and chromium. The mean age at the time of the procedure was 51.3 ± 7.1 years, 74% (206) of 280 BHRs were implanted in male patients, the mean body mass index was 27.8 ± 4.4 kg/m2, and 95% (265) of 280 hips had a primary diagnosis of osteoarthritis. The mean follow-up among all 280 hips was 9.0 ± 2.5 years. Prior to 10-year follow-up, 20 hips were revised and 5 patients representing 5 hips had died. Among the remaining 255 hips, 218 (85%) met the minimum follow-up of 10 years. RESULTS: The 10-year survival free from all-cause component revision was 92.9% (95% confidence interval [CI], 89.8% to 96.1%) for all hips and 96.0% (95% CI, 93.1% to 98.9%) among male patients <65 years old at the time of the procedure. Reasons for revision included femoral loosening (n = 5), femoral neck fracture (n = 3), pseudotumor (n = 3), osteolysis (n = 2), and acetabular loosening (n = 1), as well as 6 revisions for a combination of pain, noise, or metal levels. Among unrevised hips, the median Harris hip score improved from preoperatively (59) to 1 year postoperatively (99; p < 0.001) and remained stable through 10 years postoperatively (99; p = 0.08). Radiographically, 5% (10) of 218 unrevised hips had osteolysis with no component migration. Median metal levels had increased at 1 year postoperatively (cobalt: from 0.12 ppb preoperatively to 1.5 ppb at 1 year postoperatively, p < 0.001; chromium: from 0.6 ppb preoperatively to 1.7 ppb at 1 year postoperatively, p < 0.001), then remained stable through 5 years before slightly decreasing at 10 years postoperatively (cobalt: 1.3 ppb, p < 0.001; chromium: 1.4 ppb, p < 0.001). CONCLUSIONS: This prospective, multicenter, post-market-approval study demonstrated that the BHR implant system is safe and effective through 10 years of follow-up, particularly among young male patients. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Prevalence of Acute Myocardial Infarction and Changing Meteorological Conditions in Iran: Fuzzy Clustering Approach.

BACKGROUND: The prevalence of Acute Myocardial Infarction (AMI) varies from region to region caused by seasonal climate changes and temperature variation. This study aimed to assess the relationship between changing meteorological conditions and incidence of AMI in Iran. METHODS: This retrospective prevalence study was based on medical records of the heart center of Mazandaran Province on all patients diagnosed with AMI in Mazandaran, northern Iran between 2013 and 2015. Patients' sex and the day, month, year and time of hospital admission were extracted from patients' records. Moreover, the meteorological reports were gathered. RESULTS: A statistically significant difference was found between the distributions of AMI cases across 12 months of the year (P < 0.01). Fuzzy clustering analysis using 16 different climatic variables showed that March, April, and May were in the same cluster together. The other 9 months were in different clusters. CONCLUSION: Significant increase in AMI was seen in March, April and May (cold to hot weather).

The effects of a 12-week jump rope exercise program on body composition, insulin sensitivity, and academic self-efficacy in obese adolescent girls.

Background Childhood obesity is strongly associated with the development of cardiovascular disease (CVD). Exercise interventions have been used for obese children and adolescents to prevent the manifestation of CVD risks, such as hypertension and insulin resistance (IR). Additionally, obesity has been shown to be linked to low self-efficacy in adolescents, which has been shown to negatively impact academic performance. Therefore, the purpose of this study was to examine the effects of a 12-week jump rope exercise program on body composition, CVD risk factors, and academic self-efficacy (ASE) in obese adolescent girls with prehypertension. Methods Adolescent girls with prehypertension and obesity (n = 48, age 14-16 years) were randomly assigned to either the jump rope exercise group (EX, n = 24) or the control group (CON, n = 24). Body composition, blood pressure (BP), blood glucose, insulin levels, homeostatic model assessment of insulin resistance (HOMA-IR) (marker of IR), and ASE were assessed before and after 12 weeks of exercise training or control. Results There were significant group × time interactions following the 12-week exercise program for body fat percent, waist circumference (WC), systolic blood pressure (SBP), blood glucose, insulin levels, and HOMA-IR, which were all significantly reduced (p < 0.05). A significant improvement (p <0.05) was observed in task difficulty preference (TDP) and self-regulatory efficacy (SRE) following exercise training. Additionally, ASE was strongly correlated (r = -0.58) with body composition. Conclusions This study provides evidence that jump rope exercise intervention can be a useful therapeutic treatment to improve CVD risk factors and ASE in obese adolescent girls with prehypertension.

Whither Cochrane?

The ouster of Professor Peter Gotzsche who headed the Nordic Cochrane Centre, from Cochrane, a respected international research organisation, has provoked a crisis of confidence in the organisation's future. Disputant and bystander reactions on this issue are presented, as well as concerns regarding conflicts of interest and the reliability of Cochrane reviews. Cochrane's crisis mirrors the larger crisis of confidence that pervades the entire enterprise of medical research. We note that within weeks after Gotzsche was expelled from Cochrane, the HPV vaccine (whose Cochrane review he had publicly criticised for conflicts of interest and poor science) received a license expansion in the United States that might be worth billions of dollars to the manufacturer. Finally, we suggest a variety of new approaches that could strengthen the value of Cochrane analyses, broaden Cochrane's approach to include additional methodologies, and enhance its independence from financial interests.

Health Promotion Needs in Faith-Based Organizations: Perceptions of Religious Leaders in Bamako.

The purpose of this study was to explore imams' and pastors' perspectives of the health promotion needs of congregants in Bamako, Mali and to examine the physical environment for health promotion in faith-based organizations' (FBOs). In-depth one-on-one interviews were conducted with imams (n = 10) and pastors (n = 2) as well as observations of the physical environment in FBOs in Bamako, Mali. Data were analyzed using a content analysis approach guided by the social ecological model. Leaders frequently mentioned poverty and affordability as challenges perceived by congregants but congregants support each other with financial contributions. The main challenge mentioned was a lack of knowledge among leaders (primarily imams) about health and health programs.

Acoustic remote sensing for source localization and atmospheric tomography: Applications of the cross-correlation Green's function retrieval method.

In this work, the application of the cross-correlation Green's function retrieval method for source localization and atmospheric acoustic tomography is presented. Open field experimental measurements of an acoustic source, with an impulsive waveform, are conducted for the evaluation of an array system. Of particular interest are the source localization and sound speed estimation capabilities of the array system. The cross-correlation delay-and-sum beamformer is used to estimate source directivity and sound speed. This beamformer inherently employs the cross-correlation Green's function retrieval method between a pair of receivers. The beamforming results adequately identify the various source directions as well as the scatterers along the propagation path. Reasonable sound speed estimates are obtained at the peak frequency of the retrieved Green's functions. In the case of atmospheric acoustic tomography, the estimated sound speed from the array system can serve as an average background sound speed in a tomographic inversion algorithm. Utilizing a tomographic inversion algorithm with radial basis functions and the estimated sound speed, the reconstruction of temperature and wind velocity profiles are demonstrated.

Green's function extraction by crosscorrelation and multidimensional deconvolution for outdoor sound propagation.

In this work, the Green's function is estimated from outdoor measurements of controlled-sources. Crosscorrelation and multidimensional deconvolution have successfully been employed for Green's function retrieval. Crosscorrelation assumes a lossless medium and equipartitioned wavefield; when these assumptions are not satisfied it may result in a Green's function smeared with the source point-spread function. Multidimensional deconvolution removes the point-spread function from the retrieved Green's function. Both methods are employed to estimate the Green's function between two array stations for a single and multiple controlled-sources. The results demonstrate that the source-to-center radius has a negligible effect on the retrieved Green's function, if the source-to-center radius is larger than the distance between the two array stations.

Truth in research labelling.

This report describes the background and context of a currently circulating petition to the US Congress that seeks amendment of Section 801 of the Public Health Services Act (42 U.S.C. 282) to close a loophole in existing law which makes possible post hoc adjustment of randomised controlled trial (RCT) results reported to the Food and Drug Administration that differ from those reported to ClinicalTrials.gov and to medical journals. The report describes the petition's rationale, underlying assumptions, and support for its proposed remedy in deontological, consequentialist, and casuist philosophical ethics theories. It addresses the several reservations of the World Association of Medical Editors (WAME) with citations of evidence for the petition's assertions. The report suggests that some medical journals are not unknowing victims but rather complicit enablers of the post hoc adjusted RCT results that they publish. Its closing remarks dwell on the negative impact that embrace of a neoliberal, anti-regulatory philosophy of government will likely have on any regulatory reform to promote the integrity of biomedical science and the future of evidence-based medicine.

"Trust the researchers": flying in the face of evidence.

There are always rival hypotheses to explain away the one that is posited as the most likely to be true. Context and Occam's razor - the principle that among competing hypotheses, the one with the fewest assumptions should be selected - ultimately point to which hypothesis is the most likely to be true.

Concurrent Validity of Wearable Activity Trackers Under Free-Living Conditions.

Brooke, SM, An, H-S, Kang, S-K, Noble, JM, Berg, KE, and Lee, J-M. Concurrent validity of wearable activity trackers under free-living conditions. J Strength Cond Res 31(4): 1097-1106, 2017-The purpose of this study is to evaluate the concurrent validity of wearable activity trackers in energy expenditure (EE) and sleep period time (SPT) under free-living conditions. Ninety-five (28.5 ± 9.8 years) healthy men (n = 34) and women (n = 61) participated in this study. The total EE and SPT were measured using 8 monitors: Nike+ FuelBand SE (NFB), Garmin VivoFit (VF), Misfit Shine (MF), Fitbit Flex (FF), Jawbone UP (JU), Polar Loop (PL), Fitbit Charge HR (FC), and SenseWear Armband Mini (SWA) (criterion measures: SWA for EE and a sleep log for SPT). The mean absolute percent error (MAPE) for EE was 13.0, 15.2, 15.5, 16.1, 16.2, 22.8, and 24.5% for PL, MF, FF, NFB, FC, JU, and VF, respectively. Mean absolute percent errors were calculated for SPT to be 4.0, 8.8, 10.2, 11.5, 12.9, 13.6, 17.5, and 21.61% for VF, FF, JU, FC, MF, SWA laying down, PL, and SWA, respectively. Concurrent validity was examined using equivalence testing on EE (equivalence zone: 2,889.7-3,531.9 kcal); 2 trackers fell short of falling in the zone: PL (2,714.4-3,164.8 kcal) and FC (2,473.8-3,066.5 kcal). For SPT (equivalence zone: 420.6-514.0 minutes), several monitors fell in the zone: PL (448.3-485.6 minutes), MS (442.8-492.2 minutes), and FF (427.7-486.7 minutes). This study suggests that the PL and FC provide a reasonable estimate of EE under free-living conditions. The PL, FC, and MF were the most valid monitors used for measuring SPT.

How accurate are the wrist-based heart rate monitors during walking and running activities? Are they accurate enough?

BACKGROUND: Heart rate (HR) monitors are valuable devices for fitness-orientated individuals. There has been a vast influx of optical sensing blood flow monitors claiming to provide accurate HR during physical activities. These monitors are worn on the arm and wrist to detect HR with photoplethysmography (PPG) techniques. Little is known about the validity of these wearable activity trackers. AIM: Validate the Scosche Rhythm (SR), Mio Alpha (MA), Fitbit Charge HR (FH), Basis Peak (BP), Microsoft Band (MB), and TomTom Runner Cardio (TT) wireless HR monitors. METHODS: 50 volunteers (males: n=32, age 19-43 years; females: n=18, age 19-38 years) participated. All monitors were worn simultaneously in a randomised configuration. The Polar RS400 HR chest strap was the criterion measure. A treadmill protocol of one 30 min bout of continuous walking and running at 3.2, 4.8, 6.4, 8.0, and 9.6 km/h (5 min at each protocol speed) with HR manually recorded every minute was completed. RESULTS: For group comparisons, the mean absolute percentage error values were: 3.3%, 3.6%, 4.0%, 4.6%, 4.8% and 6.2% for TT, BP, RH, MA, MB and FH, respectively. Pearson product-moment correlation coefficient (r) was observed: r=0.959 (TT), r=0.956 (MB), r=0.954 (BP), r=0.933 (FH), r=0.930 (RH) and r=0.929 (MA). Results from 95% equivalency testing showed monitors were found to be equivalent to those of the criterion HR (±10% equivalence zone: 98.15-119.96). CONCLUSIONS: The results demonstrate that the wearable activity trackers provide an accurate measurement of HR during walking and running activities.

Five year results of the first US FDA-approved hip resurfacing device.

A prospective, multi-center postmarket approval study has been ongoing since May 2006 to assess safety and efficacy of the first US FDA approved hip resurfacing implant. 265 patients have been enrolled at five study sites. The average age of the patients is 51.3 years. There have been 7 revisions (2.4%) in the cohort to date. K-M survival curves for the cohort are 97.6% at 5 years. There is a trend toward a gender difference in implant survivorship, with 98.6% of men and 94.7% of women free from revision. Metal ion analysis revealed median cobalt and chromium levels of 1.5 ppb and 1.7 ppb at 1 year. In this prospective US study, the Birmingham Hip Resurfacing implant is demonstrating results comparable to those in the literature.

The effect of cadence on cycling efficiency and local tissue oxygenation.

The purpose of this study was to compare 3 cycling cadences in efficiency/economy, local tissue oxygen saturation, heart rate, blood lactate, and global and local rating of perceived exertion (RPE). Subjects were 14 trained cyclists/triathletes (mean age 30.1 ± 5.3 years; VO(2) peak 60.2 ± 5.0 ml·kg(-1)·min(-1)) who performed three 8-minute cadence trials (60, 80, and 100 rpm) at 75% of previously measured peak power. Oxygen consumption and respiratory exchange ratio were used to calculate efficiency and economy. Results indicated that both efficiency and economy were higher at the lower cadences. Tissue oxygen saturation was greater at 80 rpm than at 60 or 100 rpm at minute 4, but at minute 8, tissue oxygen saturation at 80 rpm (57 ± 9%) was higher than 100 rpm (54 ± 9%, p = 0.017) but not at 60 rpm (55 ± 11%, p = 0.255). Heart rate and lactate significantly increased from minute 4 and minute 8 (p < 0.05) of submaximal cycling. Local RPE at 80 rpm was lower than at 60 or 100 rpm (p < 0.05). It was concluded that (a) Trained cyclists and triathletes are more efficient and economical when cycling at 60 rpm than 80 or 100 rpm. (b); Local tissue oxygen saturation levels are higher at 80 rpm than 60 and 100 rpm; (c). Heart rate and blood lactate levels are higher with cadences of 80 and 100 than 60 rpm; and (d). Local and global RPE is lower when cycling at 80 rpm than at 60 rpm and 100 rpm. A practical application of these findings is that a cadence of 60 rpm may be advantageous for performance in moderately trained athletes in contrast to higher cadences currently popular among elite cyclists.