An Australian National University study into mammography screening and the role of fear in health messages has found high levels of psychological resistance to regular breast screening.

Conversely, however, women do recognise that mammograms lead to much earlier detection of breast cancer, they feel good about themselves when they have a mammogram and they stop worrying about cancer.

Psychologist Dr Jennifer Coyne wrote her doctoral thesis on barriers to women's participation in the ACT's free public breast-screening program. Her 2011 report found that while there was a high recognition of the benefits of finding a small cancer through mammography before it became a detectable lump, one in five women said they would prefer not to know if something was wrong.

Dr Coyne studied the attitudes of 269 Canberra women - 184 of whom were already taking part in regular screening. The remainder did not screen for breast cancer.

Her results found that 61 per cent of women believed one of the biggest barriers to getting screened was the fear of discovering cancer. Another 47.5 per cent believed it would be painful while 68 per cent had fears about being exposed to radiation.

Alarmingly, 19.5 per cent would prefer not to know if something was wrong despite the vastly improved health outcomes if cancers are detected early.

The BreastScreen Australia program has been estimated to have reduced breast cancer mortality by 21-28 per cent nationally, according to the Australian Institute of Health and Welfare. But estimates suggest 45 per cent of the female population in the increased breast cancer risk age bracket of 50-69 are not taking part in screening. The ACT currently has a screening rate of 56 per cent, against a local target of 60 per cent and a long-term target of 70 per cent.

Psychological resistance to the idea of having a mammogram appears to be a large part of the problem, although once a woman has been screened more than once, she is far more likely to continue with regular screening within the appropriate time frame.

While 16 per cent of women in the survey reported that they considered the process emotionally distressing, 10 per cent found it inconvenient and 10 per cent found it embarrassing, there was also widespread recognition of the benefits of the program.

Three-quarters of women agreed or strongly agreed that a mammogram could help them find lumps early. This would stop 65 per cent worrying about cancer, and 59 per cent would feel good about themselves as a result. A further 44 per cent agreed a mammogram could help find a lump before she or a health professional could find it.

But on the issue of whether early detection could prevent a woman requiring radical or disfiguring surgery as a result, only 24 per cent agreed, while 47 per cent were neutral and 29 per cent did not believe screening would prevent such adverse outcomes.

Professor David Roder, the University of South Australia's chair of cancer epidemiology and population health, said the ACT's low public screening rate could be explained if there was a high rate of private screening, but it was difficult to track asymptomatic screening rates within the private system.

He noted that while screening rates were low in the ACT and Canberra women showed the highest incidence of breast cancer in the nation, ACT women also enjoyed earlier diagnoses and had better survival rates. ''The ACT population is getting a really good breast cancer service and the high survival rate is testament to that,'' he said.

Professor Roder said the issue was how many women did not take up public or private screening in the ACT and how to improve public awareness of the importance of screening.

''We understand breast screening generates tension in a woman - it is usually a scary experience, and it is inconvenient. But when you consider the hours in a person's life, the small time it takes to go get screened is put into perspective.''

BreastScreen ACT director Yvonne Epping said the information generated by the service to encourage women to attend and make repeat appointments needed to strike ''the right balance between encouraging women to attend because it is a really important health check and scaring them so much they don't want to address it''.