Question

Outcome

Oral cancer examination and time since last examination

Questions about oral cancer examination were asked of participants at least 30years old. In both survey cycles, oral cancer examination was based on the question: “Have you ever had an exam for oral cancer in which the doctor or dentist pulls your tongue, sometimes with gauze wrapped around it, and feels under the tongue and inside the cheeks?” Responses were yes or no. In the 2013–2014 survey year, an additional question: “Have you had an exam for oral cancer in which the doctor or dentist feels your neck?” was asked of participants. Responses were yes or no. Of the 950 participants in the 2013–2014 survey year who reported a neck palpation examination, 650 of them reported also receiving an oral examination and 300 received only a neck palpation examination. Excluding these 300 individuals from data analysis did not meaningfully change the results, thus they were retained in all analysis. In both survey cycles, participants who responded ‘yes’ to having had an oral cancer examination were asked to report when they had the most recent oral cancer examination (within the past year, 1–3years ago and>3years ago) and the type of professional that performed the examination (Doctor/physician, Nurse/nurse practitioner, Dentists including oral surgeons, Dental Hygienists and other).

Q:- Were the outcomes measured in a valid and reliable way?

Answer 1

The study was done to monitor oral cancer examination. The study was done in two surveys. However, the questionnaire was modified in the two surveys and there was clearly a difference in the proportion of people reporting to have undergone oral cancer examination.

Howevver, as mentioned, the analysis with the added subjects did not meaningfully change the result. However, they were still not supposed to be part of the dataset. Hence the study was done unreliably. And the outcome of the study is not valid even and reliable.

In any study, it is very essential to ensure that the pattern of the study is kept constant. Even a slight modification can lead to a completely different interpretation of the result and hence modifications, if essential, can be made; but the study should be repeated.