PUBH 6036 Week 8 Measurement Memo Example

Memorandum

To: Study Team, Cedar Hollow Child Sleep and Attendance Study

From: Graduate Research Assistant

Date: Month Day, Year

Re: How "confirmed infestation in the home" will be measured at each visit

The Phrase We Must Measure

Our question calls the exposure an infestation that is "confirmed," found "in the home" and present "at the start" of the school year. Each of those words asks something of a measure. "Confirmed" means more than a belief; "in the home" means the child's apartment, not the building; "at the start" ties the reading to September. This memo compares the three practical options against that phrase, plus a fourth that was proposed and set aside, and recommends a pairing.

Option 1: Caregiver Report

A caregiver can be asked, "In the past month, have you seen bed bugs or bites from them in your home?" The question is cheap, takes seconds and captures what the family has lived with. It fails the word "confirmed." In a building-wide survey of 2,372 low-income apartments, 49% of the infestations found by inspection and trapping were in apartments whose residents were unaware of any bed bug activity (Wang et al., 2016). Bites are also a poor signal. Only 68% of residents living with confirmed infestations in that survey reported symptoms after being bitten (Wang et al., 2016). Report also carries a social risk: some caregivers will not say yes to a researcher working beside their landlord, whatever the consent form promises. Report will under-detect, and it will under-detect unevenly.

Option 2: Visual Inspection

A trained inspector can examine mattress seams, bed frames, sofa cushions and nearby baseboards for live insects, cast skins and fecal spots. Inspection is objective, can be done in 15 to 20 minutes and gives a result on the day. Its weakness is light infestations. In the New Jersey survey, brief visual inspections detected 72% of infestations (Wang et al., 2016), and inspection was less effective than interceptor cups at finding small numbers of insects in an earlier apartment study (Wang et al., 2011).

Option 3: Interceptor Cups

Interceptors are plastic dishes placed under the legs of beds and sofas; insects traveling to or from a sleeper fall in and cannot climb out. Read after seven days, they detected 89% of infestations in the New Jersey survey (Wang et al., 2016). They need no lure and no skill to place, and a reading is a count, which supports later analysis of infestation level. Their costs are a second visit to collect them, cups moved or emptied by curious children, and a week's delay, which matters little in a study that follows children all year.

The Option Set Aside: Detection Dogs

A housing partner suggested trained canine teams. In naturally infested apartments, 11 canine teams detected on average only 44% of infestations, with a mean false-positive rate of 15%, and teams varied from day to day (Cooper et al., 2014). The method costs more than inspection and adds error in both directions, so it is not recommended.

Table 1

Measures Against the Words of the Question

Note. Detection figures from Wang et al. (2016).

Recommendation: Inspection Paired With Cups

An apartment will be classed as infested if either the inspection at the first visit or the cups collected a week later find a live bed bug, egg or cast skin. In the New Jersey survey, only 2 of 291 infestations were missed by both brief inspection and interceptors together (Wang et al., 2016), so the pair comes close to the word "confirmed" while staying affordable. Caregiver report will still be collected, but as a separate variable describing what the family knew, not as the exposure. That choice also opens a useful secondary question: do children in homes with infestations their caregivers did not know about miss as many days as children whose families were aware?

What the Pairing Still Misses

The measure records presence, not intensity, unless cup counts are used. It reads one week in September, so an apartment infested in October counts as unexposed until the January visit. And it measures the apartment, not the child's bed: a child sleeping on a couch in a relative's unit some nights will carry exposure the measure cannot see. These gaps will be reported as limitations rather than hidden by the word "confirmed."

References

Cooper, R., Wang, C., & Singh, N. (2014). Accuracy of trained canines for detecting bed bugs (Hemiptera: Cimicidae). Journal of Economic Entomology, 107(6), 2171-2181. https://doi.org/10.1603/EC14195

Wang, C., Singh, N., Zha, C., & Cooper, R. (2016). Bed bugs: Prevalence in low-income communities, resident's reactions, and implementation of a low-cost inspection protocol. Journal of Medical Entomology, 53(3), 639-646. https://doi.org/10.1093/jme/tjw018

Wang, C., Tsai, W.-T., Cooper, R., & White, J. (2011). Effectiveness of bed bug monitors for detecting and trapping bed bugs in apartments. Journal of Economic Entomology, 104(1), 274-278. https://doi.org/10.1603/EC10141