Patterns of Analgesic Utilization in the Multicenter Study of Hydroxyurea (MSH).
Authors: Ballas Samir K. , McCarthy William F. , Bauseman Robert I , Castro Oswaldo L , Swerdlow Paul S. , Smith Wally , Waclawiw Myron A , Barton Bruce A 
Published: October 2019

Abstract
Abstract 2577
Poster Board II-554

Introduction:
Chronic and acute pain are characteristic of sickle cell disease (SCD). Opioids are often used at large doses to achieve pain relief. This report summarizes the relationship of patient characteristics to patterns of analgesic utilization by patients in MSH, including both at-home use and use during medical contacts requiring hospital utilization (ER or in-patient admission).

Patients and Methods:
The sample is the N=299 patients with homozygous SCD enrolled in the MSH, a randomized double-blind placebo-controlled study of hydroxyurea (HU) as a treatment for SCD. Details of the study have been previously reported (N Engl J Med 1995). Age was examined as 4 quartiles (ages 18–24, 25–29, 30–35, and 36+). For geographic location, MSH sites were clustered into 2 regions (North/South) and 4 regions (Northeast/NE, Midwest/MW, South and West). Data on analgesics use were from three sources. (1) At biweekly follow-up visits, providers recorded the type(s) and dosage of analgesic(s) used at home during that period. (2) In biweekly at-home diaries, patients reported any analgesic use each day. Data from the diaries and the follow-up visits were matched to calculate average daily doses for each biweekly period. (3) During medical contacts, providers recorded types and doses of parenteral and oral analgesics. All doses were converted into equianalgesic doses; those for hospital contacts were divided by contact duration to obtain daily averages.

Results:
Males and females did not differ in frequency of at-home analgesic use or the number of different analgesics used during each biweekly period. Equianalgesic dosing at home was numerically lower for females but the difference was not statistically significant. For hospital contacts, females were marginally less likely to report any analgesics use (p=.08) but reported more use of non-steroidal anti-inflammatories (NSAIDS) (p=.009). Equianalgesic dosing for parenteral analgesics was significantly lower for females (p=.015). There were significant age differences in at-home analgesic use. The 18–24 and 36+ quartiles used analgesics less often (p=.001) and used fewer total analgesics (p<.0001); however, equianalgesic dosing did not differ. During hospital contacts, parenteral analgesic use did not differ, but the 18–24 and 36+ age groups were more likely to use both oral analgesics (p=.009) and NSAIDS (p<.0001).By geographic location, there was extreme site-to-site variation. When grouped into 2 regions, lower in-hospital parenteral (p=.0007) dosing, marginally lower oral dosing (p=.09), and fewer total medications used (p=.08) were reported in the South. For 4 regions, frequency of at-home analgesic use and the total number of analgesics used were highest in the NE and lowest in the West. During hospital contacts, parenteral use was highest in the NE and lowest in the West, but the pattern was reversed for oral use and NSAIDs. Average daily dose in-hospital was lower in the South than in the NE or MW.

Conclusion:
In the MSH, patterns of analgesic utilization were sex, age, and location dependent. In hospital, females have lower dosing and less frequent use along with a greater likelihood of using NSAIDS, possibly substituting for parenteral use. By age, at-home use was lower in the youngest and oldest groups, and in hospital these age groups used more oral analgesics and NSAIDs – again, possibly substituting for parenteral use. Finally, regional differences suggested more frequent parenteral use in the NE, lower parenteral doses in the South, and more frequent oral and NSAID use in the West. Regional differences may reflect site- and provider-specific prescription policies and preferences, but sex and age may also significantly influence analgesic use in adult sickle cell patients.

Disclosures:
No relevant conflicts of interest to declare.