Systematic versus opportunistic risk assessment for the primary prevention of cardiovascular disease

BACKGROUND

Screening programmes can potentially identify people at high cardiovascular risk and reduce cardiovascular disease (CVD) morbidity and mortality. However, there is currently not enough evidence showing clear clinical or economic benefits of systematic screening-like programmes over the widely practised opportunistic risk assessment of CVD in primary care settings.

OBJECTIVES

The primary objective of this review was to assess the effectiveness, costs and adverse effects of systematic risk assessment compared to opportunistic risk assessment for the primary prevention of CVD.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on the Cochrane Library, MEDLINE, EMBASE on 30 January 2015, and Web of Science Core Collection and additional databases on the Cochrane Library on 4 December 2014. We also searched two clinical trial registers and checked reference lists of relevant articles. We applied no language restrictions.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) that assessed the effects of systematic risk assessment, defined as a screening-like programme involving a predetermined selection process of people, compared with opportunistic risk assessment which ranged from no risk assessment at all to incentivised case finding of CVD and related risk factors. Participants included healthy adults from the general population, including those who are at risk of CVD.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies. One review author extracted data and assessed them for risk of bias and a second checked them. We assessed evidence quality using the GRADE approach and present this in a 'Summary of findings' table.

MAIN RESULTS

Nine completed RCTs met the inclusion criteria, of which four were cluster-randomised. We also identified five ongoing trials. The included studies had a high or unclear risk of bias, and the GRADE ratings of overall quality were low or very low. The length of follow-up varied from one year in four studies, three years in one study, five or six years in two studies, and ten years in two studies. Eight studies recruited participants from the general population, although there were differences in the age ranges targeted. One study recruited family members of cardiac patients (high risk assessment). There were considerable differences between the studies in the interventions received by the intervention and control groups. There was insufficient evidence to stratify by the types of risk assessment approaches.Limited data were available on all-cause mortality (risk ratio (RR) 0.97, 95% confidence interval (CI) 0.92 to 1.02; 3 studies,103,571 participants, I² = 0%; low-quality evidence) and cardiovascular mortality (RR 1.00, 95% CI 0.90 to 1.11; 2 studies, 43,955 participants, I² = 0%), and suggest that screening has no effect on these outcomes. Data were also limited for combined non-fatal endpoints; overall, evidence indicates no difference in total coronary heart disease (RR 1.01, 95% CI 0.95 to 1.07; 4 studies, 5 comparisons, 110,168 participants, I² = 0%; low-quality evidence), non-fatal coronary heart disease (RR 0.98, 95% CI 0.89 to 1.09; 2 studies, 43,955 participants, I² = 39%), total stroke (RR 0.99, 95% CI 0.90 to 1.10; 2 studies, 79,631 participants, I² = 0%, low-quality evidence), and non-fatal stroke (RR 1.17, 95% CI 0.94 to 1.47; 1 study, 20,015 participants).Overall, systematic risk assessment appears to result in lower total cholesterol levels (mean difference (MD) -0.11 mmol/l, 95% CI -0.17 to -0.04, 6 studies, 7 comparisons, 12,591 participants, I² = 57%; very low-quality evidence), lower systolic blood pressure (MD -3.05 mmHg, 95% CI -4.84 to -1.25, 6 studies, 7 comparisons, 12,591 participants, I² = 82%; very low-quality evidence) and lower diastolic blood pressure (MD -1.34 mmHg, 95% CI -1.76 to -0.93, 6 studies, 7 comparisons, 12,591 participants, I² = 0%; low-quality evidence). One study assessed adverse effects and found no difference in psychological distress at five years (1126 participants).

AUTHORS' CONCLUSIONS

The results are limited by the heterogeneity between trials in terms of participants recruited, interventions and duration of follow-up. Limited data suggest that systematic risk assessment for CVD has no statistically significant effects on clinical endpoints. There is limited evidence to suggest that CVD systematic risk assessment may have some favourable effects on cardiovascular risk factors. The completion of the five ongoing trials will add to the evidence base.

Alga-like forms in onverwacht series, South Africa: oldest recognized lifelike forms on Earth

Spheroidal and cupshaped, carbonaceous alga-like bodies, as well as filamentous structures and amorphous carbonaceous matter occur in sedimentary rocks of the Onverwacht Series (Swaziland System) in South Africa. The Onverwacht sediments are older than 3.2 eons, and they are probably the oldest, littlealtered sedimentary rocks on Earth. The basal Onverwacht sediments lie approximately 10,000 meters stratigraphically below the Fig Tree sedimentary rocks, from which similar organic microstructures have been interpreted as alga-like microfossils. The Onverwacht spheroids and filaments are best preserved in black, carbonrich cherts and siliceous argillites interlayered with thick sequences of lavas. These lifelike forms and the associated carbonaceous substances are probably biological in origin. If so, the origins of unicellular life on Earth are buried in older rocks now obliterated by igneous and metamorphic events.

A novel nucleotide receptor in Xenopus activates the cAMP second messenger pathway

We describe a Xenopus P2Y receptor that shares only weak homology with members of the mammalian P2Y family, being most similar to human P2Y(11). When activated by nucleotide analogs, it stimulates both calcium and cAMP mobilization pathways, a feature unique, among mammalian P2Y receptors, to P2Y(11). Activity can be blocked by compounds known to act as antagonists of mammalian P2Y(11). Genomic synteny between Xenopus and mammals suggests that the novel gene is a true ortholog of P2Y(11). Xenopus P2Y(11) is transcribed during embryonic development, beginning at gastrulation, and is enriched in the developing nervous system.

REPCAT: desktop expert system for interpreting and validating laboratory data for pheochromocytoma diagnosis with the database application Omnis 7

To aid in the validation and interpretive reporting of results from multianalyte diagnostic testing for pheochromocytoma (PHEO), we have developed a desktop personal computer-based laboratory expert system (REPCAT). REPCAT utilizes a commercial database application to run procedures that assess analytical and clinical data relating to patient urine or plasma samples. REPCAT was used to evaluate the raw data from >4000 24-h urine samples submitted to our laboratory for testing for the presence of PHEO. REPCAT performed equivalently to an expert pathologist in assessing the presence and class of PHEO (epinephrine, norepinephrine, or mixed secretor). No false negatives were generated and it assigned a correct interpretation (on the basis of subsequent clinical and biochemical investigation) for each of the primary diagnostic samples from these patients.

Inhibitor effects during the cell cycle in Chlamydomonas reinhardtii. Determination of transition points in asynchronous cultures

A wide variety of inhibitors (drugs, antibiotics, and antimetabolites) will block cell division within an ongoing cell cycle in autotrophic cultures of Chlamydomonas reinhardtii. To determine when during the cell cycle a given inhibitor is effective in preventing cell division, a technique is described which does not rely on the use of synchronous cultures. The technique permits the measurement of transition points, the cell cycle stage at which the subsequent cell division becomes insensitive to the effects of an inhibitor. A map of transition points in the cell cycle reveals that they are grouped into two broad periods, the second and fourth quarters. In general, inhibitors which block organellar DNA, RNA, and protein synthesis have second-quarter transition points, while those which inhibit nuclear cytoplasmic macromolecular synthesis have fourth-quarter transition points. The specific grouping of these transition points into two periods suggests that the synthesis of organellar components is completed midway through the cell cycle and that the synthesis of nonorganellar components required for cell division is not completed until late in the cell cycle.

Carbon Compounds in Apollo 11 Lunar Samples

Are they entrapped solar wind particles, meteoritic or cometary contributions, remnants of a primordial atmosphere or products of the degassing of the Moon ?

Demineralization studies of fluoride-treated enamel using scanning electron microscopy

Enamel was treated with topical stannous fluoride and demineralized with an acetate buffer for varying periods. A scanning electron microscope comparison of the surface alterations revealed that stannous fluoride inhibited surface alterations when challenged by the acid. Evidence suggested that fluoride plays a role in the remineralization of repair of slightly etched enamel surfaces.

Scanning electron microscope studies of EDTA-treated enamel

Enamel samples that were treated with EDTA for 2, 4, 7, and 24 hours respectively, were examined by a scanning electron microsope and were compared to the appearance of sound, untreated enamel. The following features were noted: a preferential decalcification pattern of EDTA on enamel prisms, characteristics of a superficial region of enamel suggestive of the "prismless" zone, differences in prisms from the striae of Retzius when compared with those in intervening areas, and enamel surface characteristics suggestive of a "coating" or cuticle resembling enamel matrix.

Scanning electron microscope studies of dental enamel

The capability of the scanning electron microscope (SEM) was evaluated for ultrastructural studies of dental enamel. Sound, acid-etched, and EDTA-treated enamel samples were examined, It was found that acid causes demineralization of prism cores, whereas EDTA attacks their peripheral boundaries. The scanning electron microscope appears to be exceptionally well suited for studying sound and experimentally treated dental structures.