Skip directly to site content Skip directly to page options Skip directly to A-Z link Skip directly to A-Z link Skip directly to A-Z link
Volume 21, Number 2—February 2015

Refining Historical Limits Method to Improve Disease Cluster Detection, New York City, New York, USA

Alison Levin-Rector1Comments to Author , Elisha L. Wilson2, Annie D. Fine, and Sharon K. Greene
Author affiliations: New York City Department of Health and Mental Hygiene, Queens, New York, USA

Main Article

Table 4

Explanation of signals produced by HLMoriginal and HLMrefined in the 12 weekly analyses, New York City, New York, USA, May 20–August 5, 2013*

Explanation No. signals produced by HLMoriginal No. signals produced by HLMrefined
Attributable to an uncorrected bias toward signaling
Neighborhood disease count threshold too low 47† 0
Pending cases in current period 21 0
Increasing trends in baseline period 3 0
Total signals attributable to an uncorrected bias toward signaling
Attributable to the correction of a bias against signaling
Confirmatory proportion higher in current period than in baseline period 9 0
Accounted for data accrual lags 0 17
Deleted outliers in baseline period 0 2
Adjusted for decreasing trends in baseline period 0 1
Total signals attributable to the correction of a bias against signaling
Not attributable to any known systematic bias
Total signals 134 74

*HLM, historical limits method; HLMoriginal, method as originally applied in NYC prior to May 20, 2013; HLMrefined, refined method applied starting May 20, 2013.
†These were excluded from the calculation of type I and type II error rates.

Main Article

1Current affiliation: RTI International, Research Triangle Park, North Carolina, USA.

2Current affiliation: Colorado Department of Public Health and Environment, Denver, Colorado, USA.

Page created: January 20, 2015
Page updated: January 20, 2015
Page reviewed: January 20, 2015
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.