For a woman over the age of 30 years a pap smear is recommended once every 3 years if : HPV DNA is negative, is at low risk for Ca cervix and 3 consecutive annual screening are negative. Also know An annual screening is recommended in women over 30 years if she is : HPV DNA +ve or is at high risk for Ca cervix. Note:- > 70 years, Pap smear need not be done if there have not been a +ve test in the last 10 years. Ref: Essentials of Gynaecology by Lakshmi Seshadri, Edition 1, page - 467