We read with great interest a recent published paper entitled “Stability of distinct
symptom experiences in patients with chronic obstructive pulmonary disease (COPD)”
which has been recently published in the journal of Respiratory Medicine [
[1]
]. The authors assessed some quantitative and qualitative variables at different time-points
of measurement. The authors used chi-square for comparison of rate of qualitative
variables between different time-points of follow ups. Chi-square is used for comparison
of qualitative variables between independent groups, while the groups of this study
are different time-points of measurement which are completely dependent to each others.
McNemar's test is used for comparison of qualitative variables between dependent groups
such as time-points of measurement. Therefore, the authors must use McNemar's test
for comparison of qualitative variables between different time-points of measurement
which were reported in table 1 of their paper [
2
,
3
,
4
,
5
,
6
]. Moreover, the authors used one-way analysis of variance (ANOVA) or Kruskal Wallis
test for comparison of numerical variables between time-points of follow up. One-way
ANOVA and Kruskal Wallis test are used for comparison of numerical variables between
more than two independent groups. Repeated measures ANOVA and Friedman test are used
for comparison of numerical variables between more than two dependent groups such
as different time-points of measurement. Therefore, the authors must use Repeated
Measures ANOVA or Friedman test instead of one-way ANOVA or Kruskal Wallis test and
they also must use paired t-test or Wilcoxon signed rank test instead of post hoc of ANOVA [
7
,
8
,
9
,
10
].To read this article in full you will need to make a payment
Purchase one-time access:
Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online accessOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to Respiratory MedicineAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- Stability of distinct symptom experiences in patients with chronic obstructive pulmonary disease (COPD).Respir. Med. 2022; 201106944
- Seasonal variation of vitamin D and Epstein-Barr virus antibody in multiple sclerosis patients.Eur. J. Neurol. 2018; 25: e103
- Arthroscopic treatment of diffuse pigmented villonodular synovitis of the knee: complete synovectomy and septum removal-midterm results.J. Knee Surg. 2019; 32: 427-433
- Patient satisfaction following total knee arthroplasty: comparison of short-term results in rheumatoid arthritis and osteoarthritis.Arch Bone Jt Surg. 2019; 7: 61-66
- Cancer risk among patients with multiple sclerosis: a cohort study in Isfahan, Iran.Caspian J Intern Med. 2017; 8: 172-177
- Statistical comments on "Does player time-in-game affect tackle technique in elite level rugby union?".J. Sci. Med. Sport. 2018; 21: 872
- Assessment of bioelectrical activity of pelvic floor muscles.Eur. J. Phys. Rehabil. Med. 2018; 54: 645
- Comparison of clinical outcomes between different femoral tunnel positions after anterior cruciate ligament reconstruction surgery.Arch Bone Jt Surg. 2017; 5: 419-425
- Modified retro-tubercle opening-wedge versus conventional high tibial osteotomy.Orthopedics. 2011; 34: 90
- Re: changes in condylar position within 12 Months after bilateral sagittal split ramus osteotomy.J. Oral Maxillofac. Surg. 2022; 80: 581
Article info
Publication history
Published online: February 22, 2023
Accepted:
February 15,
2023
Received:
August 17,
2022
Identification
Copyright
© 2023 Elsevier Ltd. All rights reserved.
