Meta-analysis is a method to obtain a weighted average of results from various studies. In addition to pooling effect sizes, meta-analysis can also be used to estimate disease frequencies, such as incidence and prevalence. In this article we present methods for the meta-analysis of prevalence. We discuss the logit and double arcsine transformations to stabilise the variance. We note the special situation of multiple category prevalence, and propose solutions to the problems that arise. We describe the implementation of these methods in the MetaXL software, and present a simulation study and the example of multiple sclerosis from the Global Burden of Disease 2010 project. We conclude that the double arcsine transformation is preferred over the logit, and that the MetaXL implementation of multiple category prevalence is an improvement in the methodology of the meta-analysis of prevalence.

Meta-analysis of prevalence

Introduction: Osteoarthritis (OA) is a leading cause of pain and disability among adults with a current prevalence of around 15% and a predicted prevalence of 35% in 2030 for symptomatic OA. It is ...

Disease-modifying drugs in osteoarthritis: current understanding and future therapeutics.

Osteoarthritis is a complex joint disease in which all involved tissues play an important role in its onset and progression. It has been suggested that osteoarthritis is likely to be a systemic disease involving stromal cell differentiation and lipid metabolism while altered lipid metabolism has been implicated as a critical player in its pathogenesis. As excessive accumulation of free cholesterol is toxic for the cells, the accumulation of lipids in chondrocytes may signify a causal relationship to development and/or progression of osteoarthritis; therefore we investigated the expression of genes regulating reverse cholesterol transport, as ABCA1, ApoA1, LXRa, LXR_, in human osteoarthritic chondrocytes. We also investigated the effect of an LXR agonist on ABCA1 and ApoA1 expression and, for the first time, on cholesterol effiux and lipid accumulation in osteoarthritic chondrocytes. Articular cartilage samples were obtained from femoral condyles and tibial plateaus of patients with primary OA undergoing knee replacement surgery while normal cartilage was obtained from eight individuals undergoing fracture repair surgery, with no history of joint disease. Total cellular RNA was extracted from all samples and ABCA1, ApoA1, and LXRα and LXRβ mRNA and protein expression levels were evaluated using real-time PCR and Western blot analysis respectively. The effect of the synthetic LXR agonist TO-901317 was studied after treatment of osteoarthritic chondrocytes and subsequent investigation of ABCA1 and ApoA1 mRNA expression levels. Cholesterol effiux was evaluated in osteoarthritic chondrocytes radiolabeled with [1,2(n)-3H] cholesterol after LXR treatment, while intracellular lipid accumulation was studied after Oil-red-O staining. ApoA1 and ABCA1 mRNA levels were significantly lower in osteoarthritic cartilage compared to normal (p Our findings suggest that impaired expression of genes regulating cholesterol effiux may be a critical player in osteoarthritis, while the ability of the LXR agonist to facilitate cholesterol effiux suggests that it may be a target for therapeutic intervention in osteoarthritis.

Impaired expression of genes regulating cholesterol efflux in human osteoarthritic chondrocytes

It is well accepted that age is an important contributing factor to poor cartilage repair following injury, and to the development of osteoarthritis Cellular senescence, the loss of the ability of cells to divide, has been noted as the major factor contributing to age-related changes in cartilage homeostasis, function, and response to injury The underlying mechanisms of cellular senescence, while not fully understood, have been associated with telomere erosion, DNA damage, oxidative stress, and inflammation In this review, we discuss the causes and consequences of cellular senescence, and the associated biological challenges in cartilage repair In addition, we present novel strategies for modulation of cellular senescence that may help to improve cartilage regeneration in an aging population

Cellular senescence in aging and osteoarthritis

. Based on the publication in this issue of AI&R of a metanalytic assessment of the degree and the quality of the available evidences on the clinical efficacy of an otherwise diffuse utilization of nutritional integration on a spectrum of fragile patients, the methodological comment is focused on the limitations, biases, misleading implications which are today threatening the role of metanalytical analyses of existing literature, to produce useful-reliable evidences in areas where the representativeness of the source of data is substantially scarce. The exposure to such risk appears to be specifically worrying in the field of nursing care, due to the very limited availability of randomized and other "controlled" prospective original studies with hard end-points.

[About meta-analyses].

Global, regional prevalence, incidence and risk factors of knee osteoarthritis in population-based studies

Negative pressure wound therapy for surgical site infections: a systematic review and meta-analysis of randomized controlled trials

Joint stiffness is a common complication after anterior cruciate ligament (ACL) reconstruction, which seriously affects the efficacy of the operation and patient satisfaction. After ACL reconstruction, the identification of joint stiffness’ risk factors can help its prevention. This meta-analysis was conducted to evaluate joint stiffness’ risk factors and incidence after ACL reconstruction and provide guidance on its prevention. PubMed, Embase, and Cochrane Library were searched to obtain relevant studies. The odds ratios (ORs) with 95% confidence intervals (CIs) for all potential risk factors were analyzed using fixed or random-effects meta-analysis in RevMan 5.2. In total, there were 37 studies and 113,740 patients that were included in this study. After ACL reconstruction, joint stiffness’ incidence negatively correlated with the studies publication time (R = −0.62, P = 0.0094). After ACL reconstruction, the joint stiffness overall pooled incidence was 3% (95% CI, 3-4%). Gender (OR, 0.51; 95% CI, 0.38-0.68; P < 0.00001) was identified as a risk factor. Potential risk factors, such as trauma to surgery time interval, graft type, and concomitant surgery with meniscus injury, have no significant correlation with joint stiffness after ACL reconstruction. This study indicated that joint stiffness’ incidence after ACL reconstruction is 3% and that gender is a risk factor for joint stiffness after ACL reconstruction.

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Incidence and risk factors of joint stiffness after Anterior Cruciate Ligament reconstruction.

Incidence and Risk Factors for Proximal Junctional Kyphosis in Adolescent Idiopathic Scoliosis After Correction Surgery: A Meta-Analysis

The current study was aimed at exploring the potential roles and possible mechanisms of miR-10a-5p in osteoarthritis (OA). We performed RT-qPCR, Western blot, CCK8, EdU Assay, and flow cytometry assay to clarify the roles of miR-10a-5p in OA. Furthermore, the whole transcriptome sequencing together with integrated bioinformatics analyses were conducted to elucidate the underlying mechanisms of miR-10a-5p involving in OA. Our results demonstrated that miR-10a-5p was upregulated in OA and acted as a significant contributing factor for OA. A large number of circRNAs, lncRNAs, miRNAs, and mRNAs were identified by overexpressing miR-10a-5p. Functional enrichment analyses indicated that these differentially-expressed genes were enriched in some important terms including PPAR signaling pathway, PI3K-Akt signaling pathway, and p53 signaling pathway. A total of 42 hub genes were identified in the protein-protein interaction network including SERPINA1, TTR, APOA1, and A2M. Also, we constructed the network regulatory interactions across coding and noncoding RNAs triggered by miR-10a-5p, which revealed the powerful regulating effects of miR-10a-5p. Moreover, we found that HOXA3 acted as the targeted genes of miR-10a-5p and miR-10a-5p contributed to the progression of OA by suppressing HOXA3 expression. Our findings shed insight on regulatory mechanisms of miR-10a-5p, which might provide novel therapeutic targets for OA.

Hua-Ding Lu

Papers

Global, regional prevalence, incidence and risk factors of knee osteoarthritis in population-based studies

Negative pressure wound therapy for surgical site infections: a systematic review and meta-analysis of randomized controlled trials

Incidence and risk factors of joint stiffness after Anterior Cruciate Ligament reconstruction.

Incidence and Risk Factors for Proximal Junctional Kyphosis in Adolescent Idiopathic Scoliosis After Correction Surgery: A Meta-Analysis

Overexpression of miR-10a-5p facilitates the progression of osteoarthritis.