Effects of acupuncture on quality of life and pain in patients with osteoporosis—a pilot randomized controlled trial: reply to comments by Moran et al.
Effects of acupuncture on quality of life and pain in patients with osteoporosis-a pilot randomized controlled trial: reply to comments by Moran et al.
Joerg Schiller 0
0 Department of Rehabilitation Medicine, Hannover Medical School , Carl-Neuberg-Str. 1, 30655 Hannover , Germany
We appreciate the interest of Moran et al. in our
article  and their critical impulse regarding the
sample size calculation . In our paper, we present the
original sample size calculation as done for the study
protocol. This calculation of the number of cases is
b a s e d o n t h e w o r k o f I n o u e [ 3 ] a n d I t o u [ 4 ] .
However, according to the pilot character of the study
after the end of the intervention phase, we revised our
strategy for data analyses based on the large number of
measurements over time and the additional 3-month
follow-up. Mixed models are more appropriate and have
more statistical power when analyzing datasets with
repeated measurements. We agree that the paper of Guo
et al.  presents a reasonable way to calculate the
sample size when using mixed models. The mentioned
references by Kanis et al. [6, 7] have been cited in the
introduction of the manuscript and do not relate to the
sample size calculation. These references are obviously
placed incorrectly according to our continuous revision
of the manuscript. Thanks for this very helpful note, the
faulty citation is very unpleasant for us and we would
like to correct this herewith. The correct citations in the
section BStatistical analysis^ are the ones mentioned
above by Inoue  and Itou .
Compliance with ethical standards
Conflicts of interest None.
1. Schiller J , Korallus C , Bethge M , Karst M , Schmalhnofer ML , Gutenbrunner C , Fink MG ( 2016 ) Effects of acupuncture on quality of life and pain in patients with osteoporosis-a pilot randomized controlled trial . Arch Osteoporos 11 :34. doi:10.1007/s11657- 016 - 0288 -x
2. Jose M. Moran JM , Ignacio Aliaga I , Pedrera-Zamorano JD ( 2016 ) The importance of accurate sample size calculations in clinical trials . Arch Osteoporos 12 . doi: 10.1007/s11657- 016 - 0304 -1
3. Inoue M , Kitakoji H , Ishizaki N , Tawa M , Yano T , Katsumi Y , Kawakita K ( 2006 ) Relief of low back pain immediately after acupuncture treatment-a randomised, placebo controlled trial . Acupunct Med 24 ( 3 ): 103 - 108
4. Itoh K , Katsumi Y , Hirota S , Kitakoji H ( 2006 ) Effects of trigger point acupuncture on chronic low back pain in elderly patients-a sham-controlled randomised trial . Acupunct Med 24 ( 1 ): 5 - 12
5. Guo Y , Logan HL , Glueck DH , Muller KE ( 2013 ) Selecting a sample size for studies with repeated measures . BMC Med Res Methodol
6. Kanis JA , Oden A , Johnell O , De Laet C , Jonsson B ( 2004 ) Excess mortality after hospitalisation for vertebral fracture . Osteoporos Int 15 : 108 - 112
7. Kanis JA , Johnell O , Oden A , Sembo I , Redlund-Johnell I , Dawson A , De Laet C , Jonsson B ( 2000 ) Long-term risk of osteoporotic fracture in Malmo . Osteoporos Int 11 : 669 - 674