Evidence Based Medicine

Evidence-based medicine means that the formulation of a seemingly attractive hypothesis of the cause of a disease is not enough for scientific acceptance. There needs to be empirical evidence, preferably replicated in various controlled studies.

For many decades, premature ejaculation was considered to be a psychological disorder that had to be treated with psychotherapy. However, psychological treatments and underlying theories mostly relied on case reports, series of case report studies, and opinions of some leading psychotherapists and sexologists. They were not based on controlled studies. I believe this to be a typical example of authority- or opinion-based medicine (15).

In contrast to authority-based medicine, evidence-based medicine (26) has been accepted today as the hallmark for clinical research and medical practice. Particularly in last decade, randomized clinical trials with clomipramine (27,28) and some SSRIs (29-33) have repeatedly demonstrated the efficacy of serotonergic antidepressants to delay ejaculation. In spite of these studies, the belief persists among those involved in sexology that premature ejaculation is a psychological disorder. In order to unravel this dichotomy, it is important to apply principles of evidence-based medicine to both the psychological and neurobiological approaches to premature ejaculation and its treatments.

Evidence-Based Research: Psychotherapy

The psychoanalytic idea of unconscious conflicts being the cause of premature ejaculation has never been investigated in a manner that allowed generalization, as only case reports on psychoanalytic therapy have been published.

But this is also true for behavioural therapy. Masters and Johnson (21) deliberately refuted a definition of premature ejaculation in terms of a man's ejaculation time duration. Instead, they insisted on defining premature ejaculation in terms of the female partner response, for example, as a male's inability to inhibit ejaculation long enough for the partner to reach orgasm in 50% of intercourses. It is obvious that their definition is inadequate because it implies that any male partner of females who have difficulty in reaching orgasm on 50% of intercourses suffers from premature ejaculation.

Masters and Johnson argued that premature ejaculation was conditioned by experiencing first sexual contacts in a rapid way (e.g., in the back seat of a car or with an impatient prostitute). However, Masters and Johnson, and sexologists who followed their ideas, have never provided any evidence-based data for this assumption. Regarding their proposed behavioral squeeze technique treatment, Masters and Johnson claimed a 97% success for delaying ejaculation. However, this very high percentage of success has never been replicated by others.

Usually, a lack of reproducible data leads to critical comments. This is one of the basic principles of evidence-based medicine. The effects of a treatment intervention should be reproducible by others. However, critical comments were not appreciated in the traditional sexological thinking of the late 20th century. This nonscientifically supported and uncritical belief in behavioral treatment still exists today, in spite of clear evidence-based medical research in favor of the neurobiological view. But the criticism is justified. The methodological insufficiencies of the report of Masters and Johnson are very serious. Their report on the efficacy of the squeeze method contains numerous biases.

First, there was a bias in selection and allocation of the subjects, the patients were not randomized to the new squeeze technique, or the older stop-start technique, or a nonsense behavioral technique. Second, the treatment design was open and not double-blinded. Further, the diagnosis of premature ejaculation was not quantified and therefore inaccurate, particularly since Masters and Johnson used an obscure definition of premature ejaculation. Baseline data were not reported, and inclusion and exclusion criteria were lacking. The assessment of success was subjectively reported without quantification or scoring scales. In addition, Masters and Johnson did not provide any information on their data processing. In spite of all these methodological flaws, their behavioral technique has received worldwide uncritical acceptance and been promoted as the best method of treatment. Even the very poor results of two studies (34,35) on behavioral therapy (also poorly designed) could not prevent sexologists from continuing to claim the squeeze technique as the best method of treatment. Not only the squeeze technique, but also all sorts of psychotherapy, including thought stopping, Gestalt therapy, transactional analysis, group therapy, and bibliotherapy, have been proposed as being effective (36-39). Also the efficacy of these psychotherapies has only been suggested in case reports and were never investigated in well-designed controlled studies.

In my opinion, the uncritical acceptance of the squeeze technique as first choice treatment is a clear example of the influence of opinion- or authority-based medicine, as in those years Masters and Johnson were famous for their new approaches in the treatment of sexual disorders (15). It did not seem to be an issue then that Masters and Johnson—these so highly esteemed sexologists—did not produce any evidence-based data for their claimed discovery.

Evidence-Based Research: Drug Treatment

In contrast with the easily accepted behavioral treatment by sexologists, drug treatment had to prove itself far more explicitly to avoid rejection by professionals in the field. Only a few physicians have tried to develop drug strategies to treat premature ejaculation. Currently, in spite of some residual ambiguous attitudes of many sexologists, drug treatment with serotonergic antidepressants are accepted as effective therapy. Despite of all circumstantial evidence, it should be emphasized that a scientific approach to investigating empirical evidence remains obligatory (40). To investigate how far differences in methodology may be of influence on clinical outcome of drug treatment studies, Waldinger and co-workers conducted an systematic review and meta-analysis of all drug treatment studies that were published between 1943 and 2003 (41).

In this study, several methodological evidence-based criteria were compared such as study design (single-blind and open-design vs. double-blind), tools for diagnostic testing (stopwatch vs. subjective reporting or questionnaire) and means of assessment (prospective vs. retrospective). The results revealed that from 79 publications on drug treatment, 35 studies involved serotonergic antidepressants. It was clearly demonstrated that both single-blind and open-design studies as well as studies using a questionnaire or subjective report on the ejaculation time led to a higher variability, that means exaggerated responses, in ejaculatory delay. Only eight studies (27,31,33,42-46) (18.5%) fulfilled all criteria of evidence-based medicine, for example, double-blind studies prospec-tively using real time stopwatch assessments at each intercourse both at baseline and during the drug trial. Regarding daily treatment, a similar efficacy for parox-etine, clomipramine, sertraline, and fluoxetine has been demonstrated, whereas the efficacy of paroxetine was found to be clearly stronger than all aforementioned drugs.

Anxiety and Depression 101

Anxiety and Depression 101

Everything you ever wanted to know about. We have been discussing depression and anxiety and how different information that is out on the market only seems to target one particular cure for these two common conditions that seem to walk hand in hand.

Get My Free Ebook


Post a comment