Evidence from a systematic review/meta-analysis of eight RCTs of acupuncture for osteoarthritis of the knee, and from a further six RCTs, provides weak support for the use of acupuncture (traditional Chinese acupuncture or Western medical; manual, or electro-acupuncture). Results were mixed, with some trials showing effectiveness, others failing to reach statistical significance, and a few favouring the comparator intervention. Few studies lasted longer than 12 weeks, so the evidence on longer-term outcomes is limited. The National Institute for Health and Clinical Excellence (NICE) conducted a cost-consequence study and concluded that electro-acupuncture was not cost-effective, but the data were insufficient to recommend whether or not acupuncture should be regarded as affordable by the NHS.

Background

• Acupuncture in traditional Chinese medicine is a treatment in which fine needles are used to stimulate specific points identified by traditional practitioners. Acupuncture, as practised in Western medicine, places about six needles near the painful area, and possibly elsewhere. The needles are manipulated or stimulated electrically (electro-acupuncture) to produce a particular needle sensation. A course of treatment usually consists of six or more sessions.

Evidence summary

NICE conducted a systematic review of the effects of acupuncture (traditional Chinese acupuncture, Western medical acupuncture, and electro-acupuncture) on osteoarthritis [National Collaborating Centre for Chronic Conditions, 2008].

• One systematic review/meta-analysis and six additional relevant RCTs were found.
• The systematic review/meta-analysis included eight RCTs (n = 2362) of osteoarthritis of the knee.
• RCTs differed in the joints treated, types of acupuncture, comparisons made (with sham acupuncture or an active treatment), study size, and duration of follow up.
• Pain:
• Acupuncture. The meta-analysis found statistically significant benefits in three of six comparisons with no additional treatment or with sham treatments. However, the changes were small and may not be clinically important.
• Hip: one RCT found no significant benefit.
• Thumb: one small RCT (n = 13) reported mixed results for different measures of pain.
• Knee or hip: one RCT (n = 712) found a statistically and clinically significant benefit.
• Mixed (knee, hip, finger, spine): one RCT (n = 40) found no significant benefit.
• Stiffness:
• Acupuncture.
• Knee or hip: one RCT (n = 712) found a statistically and clinically significant benefit.
• Mixed (knee, hip, finger, spine): one RCT (n = 40) found no significant benefit.
• Function/disability:
• Acupuncture.
• Hip: one RCT (n = 67) found no significant benefit.
• Thumb: one small RCT (n = 13) found no significant benefit.
• Knee: one meta-analysis (four RCTs, n = 1245) found small statistically significant improvements in two of six analyses.
• Knee or hip: one RCT (n = 712) found a statistically and clinically significant benefit.
• Mixed (knee, hip, finger, spine): one RCT (n = 40) found no significant benefit.
• Long term (mixed): three RCTs (n = 1178); WMD 2.01 (95% CI 0.36 to 3.66, p < 0.05) — clinical importance not stated.
• Global assessment:
• Acupuncture.
• Hip: one RCT (n = 67) found no significant benefit at 6 weeks post intervention, but a significant improvement of 9% in reported satisfaction.
• Quality of life:
• Acupuncture.
• Hip: one RCT (n = 67) found no significant benefit.
• Knee or hip: one RCT (n = 712) found statistically significant benefit in measures of physical and mental quality of life.
• Other outcomes:
• Acupuncture.
• Knee or hip: one RCT (n = 712) found a statistically and clinically significant difference in the proportion of people regarded as responders on the WOMAC score.
• Thumb: one small RCT (n = 13) found no significant benefit on a verbal rating of improvement.
• Adverse events:
• Acupuncture: no serious adverse events were reported.
• Electro-acupuncture: no serious adverse events were reported.
• Health economic studies:
• The published evidence on health economics is limited and not easily applicable to the UK. NICE therefore conducted a cost-consequence study.
• Acupuncture:
• The incremental cost-effectiveness ratio for acupuncture may be higher than the threshold typically used by the NHS to assess affordability. However, limitations in the data mean that there is considerable uncertainty in the estimate of cost-effectiveness.
• Electro-acupuncture:
• Electro-acupuncture was considered to be definitely above the threshold of affordability.
• Limitations of the studies:
• Included studies were all of high methodological quality.
• Few studies lasted more than 12 weeks, so the evidence on long-term effects is limited, but suggests that function may be improved.
• NICE selected one study of electro-acupuncture for review, but did not include other trials that used electro-acupuncture, for example [Berman et al, 2004; Vas et al, 2004].
• If these trials had been included in the NICE review, the evidence for the effectiveness of electro-acupuncture would appear stronger.
• These trials, however, were included in the systematic review summarized by NICE and used to assess the evidence for acupuncture.
• Although the analyses used clinically relevant outcome measures (e.g. pain, function), it is difficult to assess how clinically important the benefits are.