Wittouck et al. (2011) conducted a
meta-analysis to evaluate the short-term and long-term impact of grief prevention
as well as treatment on individuals with complicated grief. They used two
methods to gather articles they needed. The first includes the electronic
databases Web of Science (WOS) and PsycArticles, the second method is utilizing
the relevant studies from the reference list. The inclusion criteria are listed
as following: 1) the study conducted the Randomized Controlled Trial (RCT) and
included a comparison group, 2) the participants of the intervention were
adults who lost their significant others, 3) the assessments included pre-and
post or follow-up evaluation, 4) the outcome variable involved the complicated
grief, 5) the study was published in peer-reviewed journal, 6) the published
year of the study was from 1990 to 2007. They excluded case studies, treatments
for diagnoses relevant to other loss, treatments for children, teenagers,
caregivers, people with intellectual disabilities or people with pet loss, treatments
for people with life-limiting diseases, and drug therapy.