Thirty seven general practitioners from 23 practices registered 182 patients. Of these patients, 164 (78 women) were randomised: 53 to receive local injection, 53 to naproxen, and 58 to placebo. Eleven of the 37 general practitioners recruited six or more patients, accounting for 94 (57%) of the 164 in the study population (overall range recruited 1-17). Allocation of intervention and baseline patient characteristics were similar in high recruiting and low recruiting practices. The figure shows the progress of patients through the trial, and table shows the baseline characteristics of the study sample.
Baseline characteristics of participants according to treatment group. Values are numbers (percentages) of participants*
At four weeks, outcome in the injection group was significantly better than in the naproxen and placebo groups (table ). Naproxen showed no advantage over placebo. Recovery or improvement was reported in 48 patients (92%) in the injection group, 30 patients (57%) in the naproxen group, and 28 patients (50%) in the placebo group.
Outcome at four weeks after invention according to treatment group. Values are numbers (percentages) of patients
Table shows median scores for the Likert scales for pain, function, and “main complaint” at each follow up assessment. At four weeks, injection showed a clear advantage over naproxen and placebo. There were some small but significant differences in favour of naproxen or placebo at 6 and 12 months.
Median (interquartile range) pain and disability self assessment scores (Likert scale 0-9) in patients with lateral epicondylitis according to treatment group
The clinical interpretation of these differences was explored as follows. Comparison between the Likert scores for pain and participants’ global assessment of change at four weeks showed that 89% of subjects scoring
3 rated themselves as completely better or improved; none had got worse. Based on this, outcome was dichotomised as “better” (pain score
3) or “not better” (pain score
4). This allowed us to compare the numbers of patients who had responded to treatment at each time point (table ). Overall, 84% of recruited patients were better at 12 months, and this proportion was similar for each treatment group (injection 84%, naproxen 85%, placebo 82%). Some subjects in the injection group, however, had worsened at six months but improved again by 12 months.
Table 4 Numbers (percentages) of patients with lateral epicondylitis who were better (pain score 3) at follow up compared with baseline according to treatment group*
Details of the self reported presence of elbow pain, the nurse’s examination findings, and disability scores are given on the BMJ’s website. Injection was superior to naproxen and placebo at four weeks; the three groups were similar at 12 months with a relapse in some patients in the injection group at six months.
The numbers of patients taking time off paid employment at four weeks were five (14%) in the injection group, four (10%) in the naproxen group, and eight (17%) in the placebo group; the numbers at 12 months were five (14%), four (10%), and 10 (21%), respectively (P>0.05 for both times). The numbers of patients taking painkillers in each group at four weeks and six and 12 months were similar: 18 (35%), 22 (42%), and 29 (50%) at four weeks; 21 (40%), 19 (36%), 23 (40%) at six months, and 14 (26%), 14 (26%), and 16 (28%) at 12 months for injection, naproxen, and placebo groups respectively.
Case notes were available for 160 participants; four had transferred practices. In all, 155 records (50 injection, 52 naproxen, 53 placebo) had information about the randomised treatment, and 151 records (49 injection, 50 naproxen, 52 placebo) had complete information concerning patient treatment between the date of referral and follow up.
Numbers of co-interventions did not differ significantly between groups during follow up (table ). A second injection was received by seven (14%) patients in the injection group; 17 (34%) patients in the naproxen group and 15 (29%) in the placebo group also received an injection during follow up. Fewer patients in the injection group reconsulted their general practitioner within four weeks of the randomised intervention, but observed consultation for tennis elbow pain was similar in all three groups by 12 months.
Numbers (percentages) of patients recorded to have reconsulted with general practitioner and received cointerventions during follow up*
Local skin atrophy at the lateral epicondyle was observed in only two patients at six months and one patient at 12 months. The three affected patients were from the naproxen and placebo groups, and only one had additionally received a local injection. Naproxen was discontinued in four patients because of gastrointestinal side effects. One patient on naproxen had an allergic reaction characterised by oedema. Pain diaries recorded for five days after intervention showed a minor, non-significant, increase in severity of pain after injection, lasting one day only.