Treatment outcomes of a Numeric Rating Scale (NRS)-guided pharmacological pain management strategy in symptomatic knee and hip osteoarthritis in daily clinical practice.
OBJECTIVE
To describe the results of a Numeric Rating Scale (NRS)-guided pharmacological pain management strategy in symptomatic knee and hip osteoarthritis (OA) in daily clinical practice.


METHODS
In this observational cohort study, standardised conservative treatment was offered to patients with symptomatic knee and/or hip OA referred to secondary care. Pain management was guided by a NRS for pain, aiming for NRS ≤4. The first step in pharmacological treatment was paracetamol (acetaminophen) in case of no recent use in adequate dose. In case of treatment failure, patients switched to a non-steroidal anti-inflammatory drug (NSAID) and eventually to a second NSAID, each after a 4-week trial period. Predictors for response to treatment were identified. Moreover, reasons for protocol violations were collected.


RESULTS
Three-hundred and forty-seven patients were included. The proportion of patients that reached a response after paracetamol, first and second NSAID was 25% (59/234), 16% (31/190) and 11% (10/87), respectively. Non-adherence to protocol occurred in 46% of cases when switch of analgesic was advised, mainly due to unwillingness of patients to change the analgesic. Identified predictors for response to analgesics included higher age, lower patient global assessment, less stiffness and more radiographic severity.


CONCLUSIONS
Adequate use of paracetamol and switching to a NSAID after failing paracetamol resulted in moderate treatment response percentages, whereas the result of a second NSAID was disappointing in patients with advanced knee and hip OA. Predictors for response included patient and disease related factors. A substantial part of patients with NRS >4 were unwilling to change their analgesics.
Department of Rheumatology, Sint Maartenskliniek, Nijmegen, The Netherlands. gijssnijders@gmail.com
Gijs F
GF
Snijders
Cornelia H M
CH
van den Ende
Bart J F
BJ
van den Bemt
Piet L C M
PL
van Riel
Frank H J
FH
van den Hoogen
Alfons A
AA
den Broeder
D000082:Acetaminophen / Q000627:therapeutic use*; D000368:Aged; D018712:Analgesics, Non-Narcotic / Q000627:therapeutic use*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D018771:Arthralgia / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D015331:Cohort Studies; D004185:Disability Evaluation; D057915:Drug Substitution; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D009426:Netherlands; D015207:Osteoarthritis, Hip / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy*; D020370:Osteoarthritis, Knee / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy*; D059408:Pain Management / Q000379:methods*; D010147:Pain Measurement; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome
D018712:Analgesics, Non-Narcotic; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000082:Acetaminophen