HR-pQCT Measures of Bone Microarchitecture Predict Fracture: Systematic Review and Meta-Analysis

High-resolution peripheral quantitative computed tomography (HR-pQCT) is a noninvasive imaging modality for assessing volumetric bone mineral density (vBMD) and microarchitecture of cancellous and cortical bone. The objective was to (1) assess fracture-associated differences in HR-pQCT bone parameters; and (2) to determine if HR-pQCT is sufficiently precise to reliably detect these differences in individuals. We systematically identified 40 studies that used HR-pQCT (39/40 used XtremeCT scanners) to assess 1291 to 3253 and 3389 to 10,687 individuals with and without fractures, respectively, ranging in age from 10.9 to 84.7 years with no comorbid conditions. Parameters describing radial and tibial bone density, microarchitecture, and strength were extracted and percentage differences between fracture and control subjects were estimated using a random effects meta-analysis. An additional meta-analysis of short-term in vivo reproducibility of bone parameters assessed by XtremeCT was conducted to determine whether fracture-associated differences exceeded the least significant change (LSC) required to discern measured differences from precision error. Radial and tibial HR-pQCT parameters, including failure load, were significantly altered in fracture subjects, with differences ranging from -2.6% (95% confidence interval [CI] -3.4 to -1.9) in radial cortical vBMD to -12.6% (95% CI -15.0 to -10.3) in radial trabecular vBMD. Fracture-associated differences reported by prospective studies were consistent with those from retrospective studies, indicating that HR-pQCT can predict incident fracture. Assessment of study quality, heterogeneity, and publication biases verified the validity of these findings. Finally, we demonstrated that fracture-associated deficits in total and trabecular vBMD and certain tibial cortical parameters can be reliably discerned from HR-pQCT-related precision error and can be used to detect fracture-associated differences in individual patients. Although differences in other HR-pQCT measures, including failure load, were significantly associated with fracture, improved reproducibility is needed to ensure reliable individual cross-sectional screening and longitudinal monitoring. In conclusion, our study supports the use of HR-pQCT in clinical fracture prediction. © 2019 American Society for Bone and Mineral Research.

Undiagnosed microscopic colitis: a hidden cause of chronic diarrhoea and a frequently missed treatment opportunity

Microscopic colitis (MC) is a treatable cause of chronic, non-bloody, watery diarrhoea, but physicians (particularly in primary care) are less familiar with MC than with other causes of chronic diarrhoea. The colon in patients with MC is usually macroscopically normal. MC can only be diagnosed by histological examination of colonic biopsies (subepithelial collagen band >10 µm (collagenous colitis) or >20 intraepithelial lymphocytes per 100 epithelial cells (lymphocytic colitis), both with lamina propria inflammation). The UK National Health Service exerts downward pressure to minimise colonoscopy referrals. Furthermore, biopsies are often not taken according to guidelines. These factors work against MC diagnosis. In this review, we note the high incidence of MC (comparable to ulcerative colitis and Crohn's disease) and its symptomatic overlap with irritable bowel syndrome. We also highlight problems with the recommendation by National Health Service/National Institute for Health and Care Excellence guidelines for inflammatory bowel diseases that colonoscopy referrals should be based on a faecal calprotectin level of ≥100 µg/g. Faecal calprotectin is <100 µg/g in over half of individuals with active MC, building into the system a propensity to misdiagnose MC as irritable bowel syndrome. This raises important questions-how many patients with MC have already been misdiagnosed, and how do we address this silent burden? Clarity is needed around pathways for MC management; MC is poorly acknowledged by the UK healthcare system and it is unlikely that best practices are being followed adequately. There is an opportunity to identify and treat patients with MC more effectively.

Revisiting Montreal: New Insights into Symptoms and Their Causes, and Implications for the Future of GERD

The Montreal definition of gastroesophageal reflux disease (GERD) provided a rationale for acid suppression medication without investigation, thus enhancing the management of the substantial symptom burden in these patients. Increased proton-pump inhibitor use has also highlighted their limitations, with one third of "typical" symptoms known to be refractory. Most refractory symptoms are ascribed to reflux hypersensitivity (RH) and functional heartburn (FH). RH may be caused by impaired esophageal mucosal barrier function and sensitization of peripheral esophageal receptors. Central sensitization may also contribute to the perception of non-pathologic reflux in RH, and the perception of physiological stimuli in FH. Importantly, mechanisms underlying GERD, RH, and FH are (in theory) not mutually exclusive, further complicating patient management. Methods used to distinguish GERD from RH and FH are impractical for use in epidemiological studies and pragmatic care and may have limited diagnostic accuracy. This is impeding accurate prevalence estimates and risk factor determination and the identification of new therapies. Direct assessment of mucosal barrier function by measuring impedance is a promising candidate for improved diagnosis. Ultimately though the concept of GERD as a composite, symptom-based entity needs re-evaluation, so that new understandings of upper GI symptoms can direct more precise management.

Patient-Centered Interventions to Improve Adherence to Statins: A Narrative Synthesis of Systematically Identified Studies

Poor adherence to statins increases cardiovascular disease risk. We systematically identified 32 controlled studies that assessed patient-centered interventions designed to improve statin adherence. The limited number of studies and variation in study characteristics precluded strict quality criteria or meta-analysis. Cognitive education or behavioural counselling delivered face-to-face multiple times consistently improved statin adherence compared with control groups (7/8 and 3/3 studies, respectively). None of four studies using medication reminders and/or adherence feedback alone reported significantly improved statin adherence. Single interventions that improved statin adherence but were not conducted face-to-face included cognitive education in the form of genetic test results (two studies) and cognitive education via a website (one study). Similar mean adherence measures were reported for 17 intervention arms and were thus compared in a sub-analysis: 8 showed significantly improved statin adherence, but effect sizes were modest (+7 to +22 % points). In three of these studies, statin adherence improved despite already being high in the control group (82-89 vs. 57-69 % in the other studies). These three studies were the only studies in this sub-analysis to include cognitive education delivered face-to-face multiple times (plus other interventions). In summary, the most consistently effective interventions for improving adherence to statins have modest effects and are resource-intensive. Research is needed to determine whether modern communications, particularly mobile health platforms (recently shown to improve medication adherence in other chronic diseases), can replicate or even enhance the successful elements of these interventions while using less time and fewer resources.

Systematic review of time trends in the prevalence of Helicobacter pylori infection in China and the USA

It has been suggested that the prevalence of Helicobacter pylori infection has stabilized in the USA and is decreasing in China. We conducted a systematic literature analysis to test this hypothesis. PubMed and Embase searches were conducted up to 19 January 2015. Trends in the prevalence of H. pylori infection over time were assessed by regression analysis using Microsoft Excel. Overall, 25 Chinese studies (contributing 28 datasets) and 11 US studies (contributing 11 datasets) were included. There was a significant decrease over time in the H. pylori infection prevalence for the Chinese studies overall (p = 0.00018) and when studies were limited to those that used serum immunoglobulin G (IgG) assays to detect H. pylori infection (p = 0.014; 20 datasets). The weighted mean prevalence of H. pylori infection was 66 % for rural Chinese populations and 47 % for urban Chinese populations. There was a significant trend towards a decreasing prevalence of H. pylori infection for studies that included only urban populations (p = 0.04; 9 datasets). This trend was no longer statistically significant when these studies were further restricted to those that used serum IgG assays to detect H. pylori infection, although this may have been because of low statistical power due to the small number of datasets available for this analysis (p = 0.28; 6 datasets). There were no significant trends in terms of changes in the prevalence of H. pylori infection over time for studies conducted in the USA. In conclusion, the prevalence of H. pylori infection is most likely decreasing in China, due to a combination of increasing urbanization, which we found to be associated with lower H. pylori infection rates, and possibly also decreasing rates of H. pylori infection within urban populations. This will probably result in a gradual decrease in peptic ulcer and gastric cancer rates in China over time.

Systematic review: the perceptions, diagnosis and management of irritable bowel syndrome in primary care--a Rome Foundation working team report

OBJECTIVE

To review studies on the perceptions, diagnosis and management of irritable bowel syndrome (IBS) in primary care.

METHODS

Systematic searches of PubMed and Embase.

RESULTS

Of 746 initial search hits, 29 studies were included. Relatively few primary care physicians were aware of (2-36%; nine studies) or used (0-21%; six studies) formal diagnostic criteria for IBS. Nevertheless, most could recognise the key IBS symptoms of abdominal pain, bloating and disturbed defaecation. A minority of primary care physicians [7-32%; one study (six European countries)] preferred to refer patients to a specialist before making an IBS diagnosis, and few patients [4-23%; three studies (two European, one US)] were referred to a gastroenterologist by their primary care physician. Most PCPs were unsure about IBS causes and treatment effectiveness, leading to varied therapeutic approaches and broad but frequent use of diagnostic tests. Diagnostic tests, including colon investigations, were more common in older patients (>45 years) than in younger patients [<45 years; five studies (four European, one US)].

CONCLUSIONS

There has been much emphasis about the desirability of an initial positive diagnosis of IBS. While it appears most primary care physicians do make a tentative IBS diagnosis from the start, they still tend to use additional testing to confirm it. Although an early, positive diagnosis has advantages in avoiding unnecessary investigations and costs, until formal diagnostic criteria are conclusively shown to sufficiently exclude organic disease, bowel investigations, such as colonoscopy, will continue to be important to primary care physicians.

Response of chronic cough to acid-suppressive therapy in patients with gastroesophageal reflux disease

BACKGROUND

Epidemiologic and physiologic studies suggest an association between gastroesophageal reflux disease (GERD) and chronic cough. However, the benefit of antireflux therapy for chronic cough remains unclear, with most relevant trials reporting negative findings. This systematic review aimed to reevaluate the response of chronic cough to antireflux therapy in trials that allowed us to distinguish patients with or without objective evidence of GERD.

METHODS

PubMed and Embase systematic searches identified clinical trials reporting cough response to antireflux therapy. Datasets were derived from trials that used pH-metry to characterize patients with chronic cough.

RESULTS

Nine randomized controlled trials of varied design that treated patients with acid suppression were identified (eight used proton pump inhibitors [PPIs], one used ranitidine). Datasets from two crossover studies showed that PPIs significantly improved cough relative to placebo, albeit only in the arm receiving placebo fi rst. Therapeutic gain in seven datasets was greater in patients with pathologic esophageal acid exposure (range, 12.5%-35.8%) than in those without (range, 0.0%-8.6%), with no overlap between groups.

CONCLUSIONS

A therapeutic benefit for acid-suppressive therapy in patients with chronic cough cannot be dismissed. However, evidence suggests that rigorous patient selection is necessary to identify patient populations likely to be responsive, using physiologically timed cough events during reflux testing, minimal patient exclusion because of presumptive alternative diagnoses, and appropriate power to detect a modest therapeutic gain. Only then can we hope to resolve this vexing clinical management problem.

Systematic review: Patterns of proton pump inhibitor use and adherence in gastroesophageal reflux disease

BACKGROUND & AIMS

Variation in how proton pump inhibitors (PPIs) are taken likely influences their clinical effectiveness, and must be considered when estimating PPI failure rates. This review aimed to systematically investigate the literature on patterns of PPI use in patients with gastroesophageal reflux disease (GERD).

METHODS

PubMed and Embase were searched (1989-May 2010) to identify observational studies providing information on patterns of PPI use in patients with GERD.

RESULTS

Of 902 studies identified, 13 met prespecified selection criteria. Across 2 database studies, 53.8%-67.7% of patients with GERD had a medication possession ratio (MPR) of >0.80. Across 2 more database studies, the mean MPR for the study population was 0.68 to 0.84. Across 3 surveys, 70%-84% of patients reported daily PPI use. In 2 surveys, the presence and severity of reflux symptoms increased PPI adherence, as did Barrett's esophagus in another 2 studies. Across 3 surveys, 11%-22.2% of patients reported twice daily PPI use, and across 6 studies 11.0%-44.8% of patients took GERD medication in addition to a PPI.

CONCLUSIONS

The results of this systematic review suggest that the majority of patients with GERD are relatively adherent to their PPI, although substantially different estimates were obtained using MPR data compared with surveys. Severe symptoms and the presence of Barrett's esophagus may increase PPI adherence, and other GERD medication is frequently taken in addition to a PPI. Limitations of studies in this area include inferring adherence from indirect MPR data, and recall bias associated with patient surveys.