Evidence map›Paper›PMID 42540495›Full record

ArticleOsteoarthritis and cartilage open2026

Comparison of the efficacy and safety of acetaminophen versus NSAIDs for the treatment of chronic pain in older adults with osteoarthritis of the hip and knee: Findings from the randomized, double-blind, parallel-group, non-inferiority RETHINK study.

Makoto Endo, Tsutomu Kawano, Masami Tokunaga, Shinya Kawahara, Taro Mawatari, Toshihiko Hara, Yasutaka Tashiro, Masahiro Matsuda, Taishi Sato, Shoji Baba and 10 more

Abstract read
In one paragraph

Article in Osteoarthritis and cartilage open, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

20 authors.

Makoto EndoDepartment of Orthopaedic Surgery, Kyushu University, Fukuoka, Japan.
Tsutomu KawanoDepartment of Orthopaedic Surgery, Kyushu Rosai Hospital, Kitakyushu, Japan.
Masami TokunagaDepartment of Orthopaedic Surgery, Fukuoka Orthopaedic Hospital, Fukuoka, Japan.
Shinya KawaharaDepartment of Orthopaedic Surgery, Kyushu University, Fukuoka, Japan.
Taro MawatariDepartment of Orthopaedic Surgery, Hamanomachi Hospital, Fukuoka, Japan.
Toshihiko HaraDepartment of Orthopaedic Surgery, Aso Iizuka Hospital, Iizuka, Japan.
Yasutaka TashiroDepartment of Orthopaedic Surgery, Kyushu Rosai Hospital, Kitakyushu, Japan.
Masahiro MatsudaDepartment of Orthopaedic Surgery, Fukuoka Orthopaedic Hospital, Fukuoka, Japan.
Taishi SatoDepartment of Orthopaedic Surgery, Kyushu University, Fukuoka, Japan.
Shoji BabaDepartment of Orthopaedic Surgery, Hamanomachi Hospital, Fukuoka, Japan.
Akihiko HamasakiDepartment of Orthopaedic Surgery, Aso Iizuka Hospital, Iizuka, Japan.
Toshio TakanoGraduate School of Health and Social Services, Saitama Prefectural University, Koshigaya, Saitama, Japan.
Masumi MiyakeAyumi Pharmaceutical Corporation, Tokyo, Japan.
Hiroyuki AonoAyumi Pharmaceutical Corporation, Tokyo, Japan.
Sanae SakamotoFukuoka Data Centre of Clinical Trials, Fukuoka, Japan.
Tempei MiyajiMeaningful Outcome Consulting Inc., Tokyo, Japan.
Mototsugu ShimokawaDepartment of Biostatistics, Yamaguchi University Graduate School of Medicine, Ube, Japan.
Sadamoto ZendaDepartment of Radiation Oncology, National Cancer Centre Hospital East, Kashiwa, Japan.
Yasuharu NakashimaDepartment of Orthopaedic Surgery, Kyushu University, Fukuoka, Japan.
RETHINK study group

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Objective: This study aimed to evaluate the non-inferiority of acetaminophen compared with non-steroidal anti-inflammatory drugs (NSAIDs) for the treatment of chronic osteoarthritis-related pain in older adults. Design: This multicenter, randomized, double-blind, parallel-group study enrolled patients aged 65 years or older with osteoarthritis-related pain. Participants were randomly assigned to receive acetaminophen (1800 mg/day) or NSAIDs (loxoprofen 180 mg/day or celecoxib 200 mg/day). The primary endpoint was the change in Brief Pain Inventory (BPI) item 3 (worst pain) score from baseline to week 8. The secondary endpoints included the change in BPI item 3 score from baseline to week 4, quality of life, gastrointestinal disorders, and renal and liver function parameters. Results: Of the 400 patients enrolled, 191 and 197 were in the acetaminophen (mean age 73.6 years; 83.2% female) and NSAID groups (mean age 73.3 years; 74.6% female), respectively. The least-squares mean change in BPI item 3 scores at 8 weeks was -1.79 in the acetaminophen group and -1.94 in the NSAIDs group. The between-group difference in BPI item 3 scores change was 0.14 (95% CI, -0.33 to 0.61). No major safety concerns were identified; however, gastrointestinal disorders occurred more frequently with NSAIDs and were the most common cause of treatment discontinuation. Conclusions: In this RETHINK study, acetaminophen achieved a similar reduction in osteoarthritis-related pain to NSAIDs in older adults after eight weeks; however, non-inferiority was not demonstrated. In terms of adverse events, acetaminophen was associated with fewer gastrointestinal disorders. These findings suggest that treatment choice may depend on the balance between analgesic efficacy and safety considerations. Trial registration number: The study is registered in the Japan Registry of Clinical Trials (jRCTs071200112).

Indexed as

AcetaminophenClinical trialNon-steroidal anti-inflammatory drugsOlder adultsOsteoarthritispain improvement

Identifiers

PMID42540495
PMCPMC13425900

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.