Interpretation of clinical trials for the treatment of diabetic neuropathy.

: Since with currently available technical equipment normoglycemic metabolic control cannot be attained in diabetic patients to prevent diabetic neuropathy, in addition to optimizing metabolic control, drugs will be necessary for prophylaxis and treatment of diabetic neuropathy to reduce compromising symptoms, to prevent debilitating late sequelae and to reduce the prognostic impact. Long-term treatment requires optimal risk-benefit-cost ratios of drugs used. For the practicing physician, it may be difficult to judge from the literature whether proposed treatments are in fact beneficial when used in general practice. The following points should be kept in mind when drawing conclusions from the literature: 1) homogeneity of the neuropathy under discussion, 2) severity of the neuropathy, 3) metabolic control, 4) sufficient numbers of probands, 5) sufficient duration of treatment, 6) definition of treatment goals and the impact of surrogate variables, 7) reproducibility of outcome measures, 8) definition of successful treatment, 9) time-dependent changes in both treatment and placebo groups, 10) adequate statistical evaluation, 11) numerical presentation of treatment results, 12) generalization of trial results, 13) tolerable side effects, and 14) publication bias.