TY - JOUR AU - Morbey, Roger AU - Elliot, Alex J. AU - Smith, Gillian E. PY - 2017/05/02 Y2 - 2024/03/29 TI - The importance of age-specific data in routine syndromic surveillance JF - Online Journal of Public Health Informatics JA - OJPHI VL - 9 IS - 1 SE - Novel algorithms, statistical or mathematical methods DO - 10.5210/ojphi.v9i1.7602 UR - https://ojphi.org/ojs/index.php/ojphi/article/view/7602 SP - AB - <div style="left: 90px; top: 320.758px; font-size: 14.1667px; font-family: sans-serif; transform: scaleX(1.08129);" data-canvas-width="63.778333333333336">Objective</div><div style="left: 105px; top: 335.709px; font-size: 14.1667px; font-family: serif; transform: scaleX(0.985193);" data-canvas-width="377.83774999999986">To investigate whether aberration detection methods for syndromic</div><div style="left: 90px; top: 352.376px; font-size: 14.1667px; font-family: serif; transform: scaleX(0.990035);" data-canvas-width="389.9913333333333">surveillance would be more useful if data were stratified by age band.</div><div style="left: 90px; top: 384.091px; font-size: 14.1667px; font-family: sans-serif; transform: scaleX(1.11768);" data-canvas-width="82.63416666666666">Introduction</div><div style="left: 105px; top: 399.043px; font-size: 14.1667px; font-family: serif; transform: scaleX(1.07157);" data-canvas-width="383.4959166666667">When monitoring public health incidents using syndromic</div><div style="left: 90px; top: 415.709px; font-size: 14.1667px; font-family: serif; transform: scaleX(0.990752);" data-canvas-width="395.47525">surveillance systems, Public Health England (PHE) uses the age</div><div style="left: 90px; top: 432.376px; font-size: 14.1667px; font-family: serif; transform: scaleX(0.984997);" data-canvas-width="395.9852499999999">of the presenting patient as a key indicator to further assess the</div><div style="left: 90px; top: 449.043px; font-size: 14.1667px; font-family: serif; transform: scaleX(0.952124);" data-canvas-width="394.63941666666665">severity, impact of the incident, and to provide intelligence on the</div><div style="left: 90px; top: 465.709px; font-size: 14.1667px; font-family: serif; transform: scaleX(0.965314);" data-canvas-width="395.2315833333333">likely cause. However the age distribution of cases is usually not</div><div style="left: 90px; top: 482.376px; font-size: 14.1667px; font-family: serif; transform: scaleX(1.02255);" data-canvas-width="390.0182499999999">considered until after unusual activity has been identified in the all-</div><div style="left: 90px; top: 499.043px; font-size: 14.1667px; font-family: serif; transform: scaleX(1.03121);" data-canvas-width="394.5246666666668">ages population data. We assessed whether monitoring specific age</div><div style="left: 90px; top: 515.709px; font-size: 14.1667px; font-family: serif; transform: scaleX(1.0126);" data-canvas-width="394.08550000000014">groups contemporaneously could improve the timeliness, specificity</div><div style="left: 90px; top: 532.376px; font-size: 14.1667px; font-family: serif; transform: scaleX(1.00075);" data-canvas-width="250.25416666666675">and sensitivity of public health surveillance.</div><div style="left: 90px; top: 564.091px; font-size: 14.1667px; font-family: sans-serif; transform: scaleX(1.07287);" data-canvas-width="58.23916666666666">Methods</div><div style="left: 105px; top: 579.043px; font-size: 14.1667px; font-family: serif; transform: scaleX(0.98846);" data-canvas-width="378.1848333333333">First, we examined a wide range of health indicators from the PHE</div><div style="left: 90px; top: 595.709px; font-size: 14.1667px; font-family: serif; transform: scaleX(0.969988);" data-canvas-width="395.1890833333333">syndromic surveillance systems to identify for further study those</div><div style="left: 90px; top: 612.376px; font-size: 14.1667px; font-family: serif; transform: scaleX(1.03156);" data-canvas-width="394.2441666666669">with the greatest seasonal variation in the age distribution of cases.</div><div style="left: 90px; top: 629.043px; font-size: 14.1667px; font-family: serif; transform: scaleX(1.00317);" data-canvas-width="393.4763333333333">Secondly, we examined the identified indicators to ascertain whether</div><div style="left: 90px; top: 645.709px; font-size: 14.1667px; font-family: serif; transform: scaleX(1.0368);" data-canvas-width="394.32916666666694">any age bands consistently lagged behind other age bands. Finally,</div><div style="left: 90px; top: 662.376px; font-size: 14.1667px; font-family: serif; transform: scaleX(0.988351);" data-canvas-width="392.8530000000001">we applied outbreak detection methods retrospectively to age specific</div><div style="left: 90px; top: 679.043px; font-size: 14.1667px; font-family: serif; transform: scaleX(0.995422);" data-canvas-width="393.37433333333325">data, identifying periods of increased activity that were only detected</div><div style="left: 90px; top: 695.709px; font-size: 14.1667px; font-family: serif; transform: scaleX(1.00314);" data-canvas-width="339.09333333333325">or detected earlier when age-specific surveillance was used.</div><div style="left: 90px; top: 727.425px; font-size: 14.1667px; font-family: sans-serif; transform: scaleX(1.08488);" data-canvas-width="51.17">Results</div><div style="left: 105px; top: 742.376px; font-size: 14.1667px; font-family: serif; transform: scaleX(1.03249);" data-canvas-width="381.6925">Seasonal increases in respiratory indicators occurred first in</div><div style="left: 90px; top: 759.043px; font-size: 14.1667px; font-family: serif; transform: scaleX(0.968212);" data-canvas-width="394.90149999999994">younger age groups, with increases in children under 5 providing</div><div style="left: 90px; top: 775.709px; font-size: 14.1667px; font-family: serif; transform: scaleX(1.0021);" data-canvas-width="393.5925">early warning of subsequent increases occurring in older age groups.</div><div style="left: 90px; top: 792.376px; font-size: 14.1667px; font-family: serif; transform: scaleX(0.960479);" data-canvas-width="394.7569999999998">Also, we found age specific indicators improved the specificity of</div><div style="left: 90px; top: 809.043px; font-size: 14.1667px; font-family: serif; transform: scaleX(0.984907);" data-canvas-width="393.02724999999975">surveillance using indicators relating to respiratory and eye problems;</div><div style="left: 90px; top: 825.709px; font-size: 14.1667px; font-family: serif; transform: scaleX(0.975339);" data-canvas-width="395.1423333333334">identifying unusual activity that was less apparent in the all-ages</div><div style="left: 90px; top: 842.376px; font-size: 14.1667px; font-family: serif; transform: scaleX(1.00073);" data-canvas-width="64.14666666666668">population.</div><div style="left: 90px; top: 874.091px; font-size: 14.1667px; font-family: sans-serif; transform: scaleX(1.10336);" data-canvas-width="85.01416666666667">Conclusions</div><div style="left: 105px; top: 889.043px; font-size: 14.1667px; font-family: serif; transform: scaleX(0.969904);" data-canvas-width="379.8791666666669">Routine surveillance of respiratory indicators in young children</div><div style="left: 90px; top: 905.709px; font-size: 14.1667px; font-family: serif; transform: scaleX(1.0055);" data-canvas-width="393.7199999999998">would have provided early warning of increases in older age groups,</div><div style="left: 90px; top: 922.376px; font-size: 14.1667px; font-family: serif; transform: scaleX(1.03949);" data-canvas-width="394.40141666666653">where the burden on health care usage, e.g. hospital admissions, is</div><div style="left: 90px; top: 939.043px; font-size: 14.1667px; font-family: serif; transform: scaleX(0.973215);" data-canvas-width="394.5090833333333">greatest. Furthermore this cross-correlation between ages occurred</div><div style="left: 90px; top: 955.709px; font-size: 14.1667px; font-family: serif; transform: scaleX(1.0254);" data-canvas-width="396.8791666666668">consistently even though the age distribution of the burden of</div><div style="left: 90px; top: 972.376px; font-size: 14.1667px; font-family: serif; transform: scaleX(1.02658);" data-canvas-width="394.2229166666666">respiratory cases varied between seasons. Age specific surveillance</div><div style="left: 90px; top: 989.043px; font-size: 14.1667px; font-family: serif; transform: scaleX(1.03577);" data-canvas-width="396.7856666666666">can improve sensitivity of outbreak detection although all-age</div><div style="left: 90px; top: 1005.71px; font-size: 14.1667px; font-family: serif; transform: scaleX(1.00315);" data-canvas-width="367.8374999999998">surveillance remains more powerful when case numbers are low.</div> ER -