Psychiatric morbidity and screening for colorectal cancer

Several studies have shown that faecal occult blood (FOB) screening reduces mortality from colorectal cancer. However, concern has been expressed that health screening may have adverse psychological effects, particularly for the group returning false positive tests.

To evaluate any adverse psychological effects associated with faecal occult blood screening.

Randomised controlled trial of faecal occult blood screening for colorectal cancer.

Psychiatric morbidity was measured, using the general health questionnaire (GHQ) before and 3 months after the offer of screening for colorectal cancer with FOB testing. Scores were related to acceptance of the screening test. A smaller cohort, who had returned positive FOB tests, had anxiety levels measured, using the Spielberger anxiety inventory (SAI), at different times during screening, investigation, and follow up.

A GHQ was sent to 2184 subjects before the offer of screening, and 1541 (70.6%) were returned. Of the 1693 subjects offered the GHQ 3 months after the offer of screening, 1303 (77%) returned it. A GHQ score of 5 or more, indicating possible psychiatric morbidity, was present in 454 subjects (29.5%) before screening and in 386 (29.6%) subjects 3 months after screening (NS). Of the 454 subjects who scored 5 or more, 241 (53.1%) accepted screening and 213 (46.9%) refused. A total of 1081 subjects scored less than 5, and of these 521 (48.2%) accepted screening and 560 (51.8%) refused (NS). Anxiety scores were measured in 100 test positive patients and were highest after notification of a positive test and before investigation by colonoscopy. In patients with false positive results, scores fell the day after colonoscopy and remained low 1 month later.

The receipt of a screening test does not cause sustained anxiety and the existence of psychiatric morbidity is not a factor affecting a person's decision to accept or refuse a screening test for colorectal cancer.