Cluster 121: birth control methods method female use surgically sterile study male 
Cluster 1404: fathering form acceptable medically birth control childbearing child willing potential 
Cluster 1577: barrier birth control study method adequate contraception abstinence agree duration 
Cluster 1835: child bearing birth potential control women use study agree practice 
Cluster 1904: birth control women potential effective men agree reproductive use childbearing 
Cluster 1945: birth control potential childbearing agree pregnancy study use test method 
Cluster 1949: protection partners barrier birth control method willing week childbearing principal 
Cluster 2345: highly effective method birth sexually control women potential childbearing trial 
Cluster 2375: birth control use effective study agree adequate acceptable forms form