TITLE:
Explanatory Variables as Evidence for Precision in Intramuscular Long-Acting Injections of Patients with Schizophrenia
AUTHORS:
Shigeaki Masuda, Sakiko Sakamaki, Yuko Yasuhara, Yueren Zhao, Kensaku Takase, Yoshihiro Kai, Tetsuya Tanioka, Rozzano C. Locsin
KEYWORDS:
Estimating Equation, Long Acting Injectable, Deltoid Muscle, Schizophrenia
JOURNAL NAME:
Open Journal of Psychiatry,
Vol.6 No.1,
January
28,
2016
ABSTRACT: Intramuscular injections
can cause damage to arteries, veins and nerves. Achieving maximum effects of
medications through precise intramuscular (IM) injections must be assured and
with certainty, particularly with long-acting injection drugs (LAI). The
purpose of this study is to determine precision in IM LAIs of patients with
schizophrenia. These evidences estimate “Distance from the Epidermis to the Under-Fascia”
(DEUF) and “Distance from Epidermis to the Upper-Arm Bone” (DEB) of the deltoid
muscle. Explanatory variables include body height, weight, body-mass index
(BMI), deltoid-muscle circumference, fat percentage and muscle mass measured by
body composition monitor. Sixty nine subjects are included based on the
Diagnostic Statistical Manual of Mental Disorders (DSM-IV, 1994), and receive
treatments of typical and atypical antipsychotic LAI. There are 46 males and 23
females with average age of 51.41 (Standard Deviation = 13.58) and ranging from
21 to 81 years who are all right-handed. Ultrasonographic data and those from
explanatory variables are calculated using Spearman’s rank correlation
coefficients. Multiple regression analysis (step-wise method/forced input
method) is performed assuming DEUF or DEB as dependent variables. Significant
correlations are found with highest adjusted R-square. Paired t-tests show
differences in average values of actual ultrasonographic measurements assigned
to DEUF or DEB, and the regression equations for accuracy. Ultrasonographic
values are assigned multiple-regression equations as true values, and the
calculated values are compared with those obtained by regression equations.
There are no significant differences observed for either the right or left arm.
The multiple regression equations for BMI and fat percentages (upper extremity
estimation) of DEUF, and for BMI and injection site circumference of estimated
DEB, successfully value the DEUF and DEB. By using these multiple regression
equations for IM injection to the deltoid-muscle, DEUF can better ensure
accurate LAI into the muscle through body monitor, DEB, and measured values of
the deltoid-muscle injection site circumference.