In patients with sickle cell disease, review of intermittent pain diaries using a single random day per week or a single week per month was shown to be comparable to review of 5 months’ worth of pain diaries, according to recent research published in Pain Medicine.
To determine the effectiveness of analyzing intermittent pain diaries, 125 patients with sickle cell disease from the Pain in Sickle Cell Epidemiology Study (PiSCeS; ClinicalTrials.gov Identifier: NCT00035763) recorded >153 days (mean 171 days) of pain diaries. The researchers compared pain measures using all days of the pain diaries (gold standard) with 4 other strategies, including diaries from a single week prior to study completion, a single month prior to study completion, a random day each week during the study period, and from the final week of each month of the study. The researchers compared percent pain days, percent self-defined crisis days, mean pain on all days, and mean pain on pain days with the gold standard and the four other strategies.
Analyses of a single day per week were statistically equivalent to the gold standard for all pain measures. In a similar manner, analyses of a single week per month yielded statistically equivalent results for all measures except mean pain intensity on crisis days (P <.05).
For the pain diaries from a single week prior and single month prior to the study completion, mean pain intensity on all pain days and on noncrisis days was statistically equivalent to the gold standard.
In regression analysis, the strategies of 1 week per month and 1 day per week resulted in well-calibrated percent pain days (R2: 0.981 and 0.987, respectively). The 1-day-per-week strategy was also well aligned with percent crisis days (R2=0.976).
The study investigators explained that the results “provide useful new methodologic information about the validity of pain diaries to assess pain in [sickle cell disease] and show that pain diary-based measures may not necessarily require high cost or be burdensome to patients.” They further concluded that pain diary assessments may “work for any trial measuring symptoms in [sickle cell disease] for up to six months.”
Smith WR, McClish DK, Levenson J, et al. Predictive ability of intermittent daily sickle cell pain assessment: the PiSCES Project [published online September 26, 2017]. Pain Medicine. doi:10.1093/pm/pnx214