Prevalence and Predictors of Distress
A few studies have investigated the prevalence of distress as measured by the NCCN Distress Thermometer.[4,6,7,8,9,10] Prevalence rates range from 22% to 58%. Different cutoff scores have been used, with most studies using a cutoff score of 4 or 5. Before these empirical investigations were conducted, the NCCN recommended use of a cutoff score of 5.
An initial pilot study  reported that 28.6% of 93 men with prostate cancer reported distress scores higher than 5 on a scale of 0 to 10. Another study (N = 50) reported that 50% of men and women who were potential candidates for bone marrow transplant reported distress scores higher than 5.
A third study  of 68 mixed types of cancer patients recommended the use of a range of cutoff scores with corresponding levels of intervention. For example, patients scoring between 0 and 3 would receive no further services, and patients scoring between 4 and 6 would receive educational information about available resources (e.g., self-help groups, support groups, mental health professionals) and the offer of a referral that the patient could accept, if desired. Patients scoring between 7 and 10 would receive complete psychosocial assessment and ongoing services by an appropriate health care professional. Utilizing this format, the study found that 22% of patients scored within the range of 7 to 10, and an additional 31% scored within the range of 4 to 6, resulting in 53% who reported distress scores higher than 4 on a scale of 1 to 10. The largest study to date (N = 380) reported that 58% of females and 42% of males reported distress scores higher than 4.
In regard to prevalence of distress along the clinical course, one study of 236 newly diagnosed breast cancer patients (awaiting their initial consultation with a surgical oncologist) found that 41% reported distress scores higher than 5 on the NCCN Distress Thermometer. In this same group of women, 11% reported symptoms suggestive of major depression, and 10% reported symptoms of posttraumatic stress.
In a study of 321 women with newly diagnosed stage I to stage III breast cancer, the ability of the single-item Distress Thermometer to specifically predict depression, as measured by a self-report questionnaire of the nine Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) symptoms for major depressive disorder, was investigated. Sensitivity and specificity characteristics were evaluated, and the optimal cutoff score of 7 was identified, resulting in a sensitivity of 0.81 and a specificity of 0.85 for detecting depression. Therefore, individuals scoring 7 or above should undergo a more thorough psychosocial evaluation.
Regarding predictors of distress, in a large sample (N = 380) of patients with mixed cancer diagnoses, those reporting a score of 4 or higher on the Distress Thermometer were more likely to be women, to have poorer functional performance (self-reported Karnofsky Performance Scale), and to have reported (on the Problem List that accompanies the Distress Thermometer) problems with housing, dealing with children, dealing with partner, depression, fears, nervousness, sadness, worry, and 14 of 20 physical ailments.