A retrospective analysis of interruptive versus non-interruptive clinical decision support for identification of patients needing contact isolation

BACKGROUND

In determining whether clinical decision support (CDS) should be interruptive or non-interruptive, CDS designers need more guidance to balance the potential for interruptive CDS to overburden clinicians and the potential for non-interruptive CDS to be overlooked by clinicians.

OBJECTIVE

(1)To compare performance achieved by clinicians using interruptive CDS versus using similar, non-interruptive CDS. (2)To compare performance achieved using non-interruptive CDS among clinicians exposed to interruptive CDS versus clinicians not exposed to interruptive CDS.

METHODS

We studied 42 emergency medicine physicians working in a large hospital where an interruptive CDS to help identify patients requiring contact isolation was replaced by a similar, but non-interruptive CDS. The first primary outcome was the change in sensitivity in identifying these patients associated with the conversion from an interruptive to a non-interruptive CDS. The second primary outcome was the difference in sensitivities yielded by the non-interruptive CDS when used by providers who had and who had not been exposed to the interruptive CDS. The reference standard was an epidemiologist-designed, structured, objective assessment.

RESULTS

In identifying patients needing contact isolation, the interruptive CDS-physician dyad had sensitivity of 24% (95% CI: 17%-32%), versus sensitivity of 14% (95% CI: 9%-21%) for the non-interruptive CDS-physician dyad (p = 0.04). Users of the non-interruptive CDS with prior exposure to the interruptive CDS were more sensitive than those without exposure (14% [95% CI: 9%-21%] versus 7% [95% CI: 3%-13%], p = 0.05).

LIMITATIONS

As with all observational studies, we cannot confirm that our analysis controlled for every important difference between time periods and physician groups.

CONCLUSIONS

Interruptive CDS affected clinicians more than non-interruptive CDS. Designers of CDS might explicitly weigh the benefits of interruptive CDS versus its associated increased clinician burden. Further research should study longer term effects of clinician exposure to interruptive CDS, including whether it may improve clinician performance when using a similar, subsequent non-interruptive CDS.

Modelling asthma in macaques: longitudinal changes in cellular and molecular markers

The aim of the present study was to determine whether systemic sensitisation and chronic aeroallergen challenge in macaques replicate the classical and emerging immunology and molecular pathology of human asthma. Macaques were immunised and periodically challenged over 2 yrs with house dust mite allergen. At key time-points, serum, bronchoalveolar lavage (BAL) and bronchial biopsies were assayed for genes, proteins and lymphocyte subpopulations relevant to clinical asthma. Immunisation and periodic airway challenge induced changes in immunoglobulin E, airway physiology and eosinophilia consistent with chronic, dual-phase asthma. Sensitisation increased interleukin (IL)-1β and -6 concentrations in serum, and IL-13 expression in BAL cells. Airway challenge increased: early expression of IL-5, -6, -13 and -19, and eotaxin; and variable late-phase expression of IL-4, -5 and -13, and thymus- and activation-regulated chemokine in BAL cells. CD4+ lymphocytes comprised 30% of the CD3+ cells in BAL, increasing to 50% in the late phase. Natural killer T-cells represented <3% of the CD3+ cells. Corticosteroid treatment reduced serum histamine levels, percentage of CD4+ cells and monocyte-derived chemokine expression, while increasing CD3+ and CD8+ cells in BAL. Sensitisation and periodic aeroallergen challenge of cynomolgus macaques results in physiological, cellular, molecular and protein phenotypes, and therapeutic responses observed in human asthma, providing a model system useful in target and biomarker discovery, and translational asthma research.

CCL18/DC-CK-1/PARC up-regulation in hypersensitivity pneumonitis

Hypersensitivity pneumonitis (HP) is a lung inflammatory disorder characterized by accumulation of T lymphocytes. However, the mechanisms implicated in this process remain undefined. We examined the expression of dendritic cell (DC)-derived CC chemokine 1 (CK1)/CCL18, a chemokine putatively involved in naive T cell recruitment, in lungs from 10 patients with HP, 9 patients with idiopathic pulmonary fibrosis (IPF), and 20 healthy lungs. CCL18 was measured by real-time quantitative PCR and localized in lungs by in situ hybridization and immunohistochemistry. CCL18 expression was significantly increased in lungs affected by HP in comparison with lungs affected by IPF (2,085+/-393 vs. 1,023+/-110; P<0.05) and controls (2,085+/-393 vs. 467+/-94; P<0.01). Macrophages, DCs, and alveolar epithelial cells were the main sources of CCL18. There was a direct correlation between the levels of tissue CCL18 and the number of lymphocytes in the bronchoalveolar lavage fluids. High levels of CCL18 were detected in the subacute rather than the chronic phase of HP. These findings suggest a role for CCL18 in the pathogenesis of HP.

CD95 (Fas)-dependent elimination of self-reactive B cells upon interaction with CD4+ T cells

The recessive mouse mutations lpr and gld create deficiencies in an interacting pair of cell surface molecules, CD95 (Fas/APO-1) and Fas-ligand (FasL), respectively, resulting in autoantibody production resembling human systemic lupus erythematosus. The mechanisms of self-tolerance affected by deficiency in either molecule are not established, but CD95 deficiency both in B cells and in CD4+ T cells recognizing major histocompatibility complex (MHC) class II molecules is required for autoimmunity in lpr mice. Here we track the outcome of in vivo interactions between B cells and CD4+ T cells that recognize a transgene-encoded autoantigen, hen egg lysozyme (HEL), using cells from mice transgenic for immunoglobulin and T-cell receptor (TCR) genes. B cells that had not previously encountered HEL autoantigen (naive cells) were triggered into proliferation and antibody production upon interaction with antigen and HEL-specific CD4+ T cells. By contrast, B cells that had been chronically exposed to HEL during their development and carried desensitized surface immunoglobulin (sIg) antigen receptors (anergic cells) did not produce antibody but instead were eliminated in the presence of HEL-specific CD4+ T cells. CD95-deficient anergic B cells, however, were not eliminated by CD4+ T cells and were triggered to proliferate. These findings identify a novel regulatory step for eliminating autoreactive B cells that seems unique in its dependence on CD95.