Evidence for models of diagnostic service provision in the community: literature mapping exercise and focused rapid reviews

Background Current NHS policy favours the expansion of diagnostic testing services in community and primary care settings. Objectives Our objectives were to identify current models of community diagnostic services in the UK and internationally and to assess the evidence for quality, safety and clinical effectiveness of such services. We were also interested in whether or not there is any evidence to support a broader range of diagnostic tests being provided in the community. Review methods We performed an initial broad literature mapping exercise to assess the quantity and nature of the published research evidence. The results were used to inform selection of three areas for investigation in more detail. We chose to perform focused reviews on logistics of diagnostic modalities in primary care (because the relevant issues differ widely between different types of test); diagnostic ultrasound (a key diagnostic technology affected by developments in equipment); and a diagnostic pathway (assessment of breathlessness) typically delivered wholly or partly in primary care/community settings. Databases and other sources searched, and search dates, were decided individually for each review. Quantitative and qualitative systematic reviews and primary studies of any design were eligible for inclusion. Results We identified seven main models of service that are delivered in primary care/community settings and in most cases with the possible involvement of community/primary care staff. Not all of these models are relevant to all types of diagnostic test. Overall, the evidence base for community- and primary care-based diagnostic services was limited, with very few controlled studies comparing different models of service. We found evidence from different settings that these services can reduce referrals to secondary care and allow more patients to be managed in primary care, but the quality of the research was generally poor. Evidence on the quality (including diagnostic accuracy and appropriateness of test ordering) and safety of such services was mixed. Conclusions In the absence of clear evidence of superior clinical effectiveness and cost-effectiveness, the expansion of community-based services appears to be driven by other factors. These include policies to encourage moving services out of hospitals; the promise of reduced waiting times for diagnosis; the availability of a wider range of suitable tests and/or cheaper, more user-friendly equipment; and the ability of commercial providers to bid for NHS contracts. However, service development also faces a number of barriers, including issues related to staffing, training, governance and quality control. Limitations We have not attempted to cover all types of diagnostic technology in equal depth. Time and staff resources constrained our ability to carry out review processes in duplicate. Research in this field is limited by the difficulty of obtaining, from publicly available sources, up-to-date information about what models of service are commissioned, where and from which providers. Future work There is a need for research to compare the outcomes of different service models using robust study designs. Comparisons of ‘true’ community-based services with secondary care-based open-access services and rapid access clinics would be particularly valuable. There are specific needs for economic evaluations and for studies that incorporate effects on the wider health system. There appears to be no easy way of identifying what services are being commissioned from whom and keeping up with local evaluations of new services, suggesting a need to improve the availability of information in this area. Funding The National Institute for Health Research Health Services and Delivery Research programme

Tuberculosis and HIV infection: the global setting.

Tuberculosis (TB) and human immunodeficiency virus (HIV) infection make each other's control significantly more difficult. Coordination in addressing this "cursed duet" is insufficient at both global and national levels. However, global policy for TB/HIV coordination has been set, and there is consensus around this policy from both the TB and HIV control communities. The policy aims to provide all necessary care for the prevention and management of HIV-associated TB, but its implementation is hindered by real technical difficulties and shortages of resources. All major global-level institutions involved in HIV care and prevention must include TB control as part of their corporate policy. Country-level decision makers need to work together to expand both TB and HIV services, and civil society and community representatives need to hold those responsible accountable for their delivery. The TB and HIV communities should join forces to address the health-sector weaknesses that confront them both

VCP associated inclusion body myopathy and paget disease of bone knock-in mouse model exhibits tissue pathology typical of human disease.

Dominant mutations in the valosin containing protein (VCP) gene cause inclusion body myopathy associated with Paget's disease of bone and frontotemporal dementia (IBMPFD). We have generated a knock-in mouse model with the common R155H mutation. Mice demonstrate progressive muscle weakness starting approximately at the age of 6 months. Histology of mutant muscle showed progressive vacuolization of myofibrils and centrally located nuclei, and immunostaining shows progressive cytoplasmic accumulation of TDP-43 and ubiquitin-positive inclusion bodies in quadriceps myofibrils and brain. Increased LC3-II staining of muscle sections representing increased number of autophagosomes suggested impaired autophagy. Increased apoptosis was demonstrated by elevated caspase-3 activity and increased TUNEL-positive nuclei. X-ray microtomography (uCT) images show radiolucency of distal femurs and proximal tibiae in knock-in mice and uCT morphometrics shows decreased trabecular pattern and increased cortical wall thickness. Bone histology and bone marrow derived macrophage cultures in these mice revealed increased osteoclastogenesis observed by TRAP staining suggestive of Paget bone disease. The VCP(R155H/+) knock-in mice replicate the muscle, bone and brain pathology of inclusion body myopathy, thus representing a useful model for preclinical studies

VCP Associated Inclusion Body Myopathy and Paget Disease of Bone Knock-In Mouse Model Exhibits Tissue Pathology Typical of Human Disease

Dominant mutations in the valosin containing protein (VCP) gene cause inclusion body myopathy associated with Paget's disease of bone and frontotemporal dementia (IBMPFD). We have generated a knock-in mouse model with the common R155H mutation. Mice demonstrate progressive muscle weakness starting approximately at the age of 6 months. Histology of mutant muscle showed progressive vacuolization of myofibrils and centrally located nuclei, and immunostaining shows progressive cytoplasmic accumulation of TDP-43 and ubiquitin-positive inclusion bodies in quadriceps myofibrils and brain. Increased LC3-II staining of muscle sections representing increased number of autophagosomes suggested impaired autophagy. Increased apoptosis was demonstrated by elevated caspase-3 activity and increased TUNEL-positive nuclei. X-ray microtomography (uCT) images show radiolucency of distal femurs and proximal tibiae in knock-in mice and uCT morphometrics shows decreased trabecular pattern and increased cortical wall thickness. Bone histology and bone marrow derived macrophage cultures in these mice revealed increased osteoclastogenesis observed by TRAP staining suggestive of Paget bone disease. The VCPR155H/+ knock-in mice replicate the muscle, bone and brain pathology of inclusion body myopathy, thus representing a useful model for preclinical studies

Vacuoles, inclusion bodies and centrally located nuclei in 9–10 month and 15 month old wild-type and R155H knock-in mouse muscle.

<p><b>H&E - Hematoxylin and Eosin; Ub – Ubiquitin; TDP-43 – TarDNA Binding Protein-43; IHC- Immunohistochemical staining; WT- Wild Type; R155H – Heterozygous knock in.</b></p

Immunohistochemical analysis in the wild-type and VCP^R155H/+ knock-in mouse muscle.

<p>(A–C) Quadricep muscles from 9–10 month-old wild-type and VCP^R155H/+ knock-in mice were analyzed by H&E staining. (B) An enlarged vacuole in the mutant tissue is shown by white arrows and (C) centrally located nuclei and rimmed vacuoles are revealed in the mutant mice shown by white arrows. (D) Quadriceps muscles from 15-month old VCP^R155H/+ knock-in mice, centrally located nuclei shown by white arrows. (E–F) Modified Gomori Trichrome staining of muscle fibers from wild type and VCP^R155H/+ knock-in mice. Magnification: 630×. (G–L) Electron microscopy analyses of the mouse quadricep muscles. Vacuolization and loss of myofilament organization are observed in quadriceps muscle from 10-month-old VCP^R155H/+ knock-in mice (G–I), but not in wild-type mice (J–L). Sarcomeric direction is indicated by white double ended arrow (H,K). Swollen mitochondria are also observed in the mutant tissue (L). Black arrows in (K) and (L) indicate accumulation of vacuoles. Size bars are shown in the lower left corner of each image. Mt  =  mitochondria. Magnifications: E+H  = 900×, F+I  = 2,950×, G+J  = 11,500×. (N = 3 WT and 3 R155H animals).</p