br surgery was low However tracking outcomes
surgery was low. However, tracking outcomes longitudinally improved the strength of our inferences by accounting for changes in functional status that occur naturally over time. Even with this sample size, we observed differences in func-tional status, minimizing the concern that this study was underpowered.
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Figure 3. Changes* in ADL (A), PCS (B) and MCS (C) scores among patients undergoing Actinomycin D and their matched non-cancer peers.*Changes are based on 2 surveys. For the radiation patients, one survey is prior to radiation and one survey is after radiation. In the matched noncancer group, the time interval between the 2 surveys is matched with that of the radiation patients. Compared with matched noncancer patients, radiation patients experienced no differences in ADL, PCS, or MCS scores over time (all P > 0.05). The P value is testing if the change in the outcome (ADL, PCS, or MCS) from before to after differs by treatment. A positive slope represents a decline in functional status for ADL’s and an improvement in functional status for PCS and MCS scores. Some confidence intervals are too small to be seen in figure. Abbreviations: ADL, activities of daily living; MCS, mental component summary; PCS, physical component summary.
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Third, as with all observational studies, there was concern for confounding. To account for this limitation, we con-ducted rigorous propensity score analyses, matching patients based on several sociodemographic characteristics. Further, to obtain the best matching, we performed separate analyses for each of the three treatment groups, picking the most appropriately matched noncancer peers in each case.
Fourth, among the conservative management group, SEER does not allow us to differentiate primary androgen deprivation therapy from active surveillance and watchful waiting. However, primary androgen deprivation therapy for localized prostate cancer is uncommon and not recom-mended by guidelines18 and there was no difference in quality of life between the conservative management and control groups, even though including primary androgen deprivation therapy among the conservative management patients would overestimate their decline in functional status, if anything.
Despite these limitations, our study highlights 2 impor-tant findings. First, patients undergoing conservative man-agement or radiation treatment for prostate cancer do not show a decline in their general functional status beyond what would be expected with aging. Second, patients undergoing surgery experience a slight decline in their physical function and emotional well-being, although this difference is not likely to be clinically significant. More nuanced measures of functional status may better eluci-date changes in general functional status among this typi-cally healthy population.
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