**3. Measures**

The Charlson Comorbidity Index (CCI) is a validated measure of co-morbidity. We used a patient self-reported CCI scale that asked about the presence and severity of 12 chronic conditions; the Prostate Cancer Outcomes Study used this CCI version.15 Score categories are 0, 1, 2, and 3 or more diseases.

The NCCN practice guidelines had recommended, for the first time in 2007,8 that the health adjusted life expectancy of LPC patients can be estimated by weighting age-based life expectancy by 1.5 for patients in the highest health quartile, using no weighting for patients in the middle 2 health quartiles, and weighting by 0.5 for patients in the lowest health quartile. We used co-morbidity scores as surrogate markers of health status because comorbidity is the main determinant of life expectancy in older patients, 16 and the most important prognostic factor for patients with LPC who are <75 years old is the co-morbidity score. 17 We categorized patients into health quartiles by using their CCI score (0 disease score = highest health quartile; 1 or 2 disease score = middle 2 health quartiles; 3 or higher disease score = lowest health quartile). Our basis of equating a 1 or 2 disease score with the middle 2 health quartiles was that almost half (49%) of the 3173 patients newly diagnosed with LPC in a Prostate Cancer Outcomes Study15 had a disease score of 1 or 2, and almost half (55.5%) of our patients had a disease score of 1 or 2. Both studies used the same version and scoring of the CCI. Patients were placed in 4 CALE categories: <5 years, 5 to 10 years, 10 to 20 years, and 20 years. These 4 categories were scored, respectively, from 1 to 4.

Patients were asked the following 2 questions: "How long do you expect you will live *without*  any treatment for prostate cancer?" (Q1) and "How long do you expect you will live after treatment for prostate cancer?" (Q2). The possible responses to both questions were grouped into 4 categories (similar to the CALE categories): <5 years, 5 to 10 years, 10 to 20 years, and >20 years. These 4 categories were also scored from 1 to 4, respectively. Based on Q1, Q2, and CALE scores, we calculated the patient's PDLO (which is CALE category score minus Q1 category score) and the patient's PILT (which is Q2 category score minus Q1 category score). A PDLO of 10 or more years is at least a 2-category difference between the CALE category and the Q1 category; this is only possible if the CALE was >20 years and the Q1 response was 5 to 10 years or if the CALE was 10 to 20 years and the Q1 response was <5 years. Similarly, a PILT of 10 or more years indicates that the response to Q2 was 10 years or more than the response to Q1. We conducted ordinal logistic regression analyses to identify the main socio-demographic, health, and cancer characteristics that could predict PDLO and PILT of 10 or more years.

The following validated self-administered scales were used. (1) The Short-Form 36 (SF-36, version 2) measures generic HRQOL; we calculated physical component summary and mental component summary scores from SF-36 data.18 (2) The Prostate Cancer Index measures urinary, sexual, and bowel symptoms and how much they bother the patient.19 (3) The Duke Activity Status Index20 measures functional capacity in metabolic equivalents; this scale asks patients whether they could perform 12 activities which have different levels of exertion. (4) The Hospital Anxiety and Depression Scale measures the presence and severity of anxiety and depression.21 (5) The Fear of Cancer Recurrence Scale measures the fear of possible cancer recurrence.22 (6) The Medical Outcomes Study Social Support Survey measures social support in an overall score that includes multidimensional sub-scores. 23 (7) The Delighted-Terrible Seven Faces Scale24 was used to measure patient satisfaction with life, health, and with education given by physicians about treatment options for LPC. (8) The Rapid Estimation of Health Literacy in Medicine scale, discussed earlier, measures health literacy; this was the only scale administered by telephone.14
