Question

BACKGROUND:

Previous studies based on limited exposure assessment have suggested that Parkinson's disease (PD) is associated with pesticide exposure. The authors used data obtained from licensed private pesticide applicators and spouses participating in the Agricultural Health Study to evaluate the relation of self-reported PD to pesticide exposure.

RESEARCH DESIGN AND METHODS:

Study participants were farmers recruited from North Carolina and Iowa, after demonstrating interest in participating (enrolled in 1993-1997). Participants provided detailed information on their lifetime pesticide use, including cumulative number of days of use and whether pesticides were handled personally by them. At follow-up in 1999-2003, 68% of the cohort was interviewed. Cases were defined as participants who self-reported physician-diagnosed PD at enrolment (n = 181). Cases were compared with study participants who did not report PD (n = 79,557).

what sampling method is used in this study: random, convenience or systematic?

Answer 1

The sampling method used in this study is Convenience sampling.

Explanation:

It is a type of non-probability sampling method where the sample is taken from a group of people who are easy to contact or who are easily available.

In this method there are no other criteria to the sampling method except that people be available and willing to participate.

-According to the study, the study participants were farmers recruited, after demonstrating interest in participating.

-Moreover, the Cases were defined as participants who self-reported and were compared with study participants who did not report PD.

All these points proves that the participants joined the study because they were willing to participate ie, convenience sampling and did not involve any selection criteria other than their availability hence were not selected randomly or systematically.