Are the Effects of Gambling Treatment Overestimated?

Abstract

Background Studies of clinical trials across the field of healthcare found use of designs that overestimate treatment effects. Objective review clinical trial designs used to develop gambling treatment evidence base for suitability to assess cause and effect and to accurately assess treatment effects. Methods literature review, grading of evidence, proportions and confidence limits Results The majority of published studies on gambling treatment are methodologically unsuited to determine treatment effects. Suitable (randomized and controlled) trails often use designs that can overestimate treatment effects. Attrition in published studies of gambling treatment is substantial, ranging from 11 to 83%. If attrition is not included in the analysis, overestimation of treatment effects may be similar in magnitude. Conclusions The current evidence may overestimate gambling treatment effects. The inclusion of intention to treat analysis, careful blinding, more equivalent control groups and measures of adherence to treatment would improve problem gambling treatment clinical trial design.

How Well are We Helping Problem Gamblers? An Update to the Evidence Base Supporting Problem Gambling Treatment

“…A previous review of the problem gambling treatment literature (Westphal 2007) found lack of comparable control groups as common finding among problem gambling treatment studies. Chambless and Ollendick (2001) use type of control group as one of the study criteria for determining their three categories (well-established, possibly efficacious, and experimental) and Sackett et al (1998) also use comparable control group as one their criteria for assessment of study quality.…”

“…Shaffer et al (2005) reported that only 17% of their large sample completed or substantially completed treatment. A recent review also found that gambling treatment of all types is associated with significant attrition (Westphal 2007). In a review of published gambling treatment studies from 1982 through 2005, Westphal (2007) found that attrition rates in short term pharmacological treatment studies ranged from 11.3 to 40% and in long term studies ranged from 48.3 to 59.4%.…”

“…A recent review also found that gambling treatment of all types is associated with significant attrition (Westphal 2007). In a review of published gambling treatment studies from 1982 through 2005, Westphal (2007) found that attrition rates in short term pharmacological treatment studies ranged from 11.3 to 40% and in long term studies ranged from 48.3 to 59.4%. Psychosocial treatment studies ranged between 32 and 55.4% attrition.…”

“…This robust non-specific response to treatment must be considered when evaluating treatment studies, especially studies with non-equivalent control groups (Djulbegovic et al 2003;Westphal 2007;Westphal and Abbott 2006). Studies that are not blinded and do not have equivalent control groups are highly likely to overestimate treatment effects (Djulbegovic et al 2003;Westphal 2007;Westphal and Abbott 2006) by including nonspecific effects with the specific effects of treatment.…”

Emerging Conceptual Models of Excessive Behaviors

“…Serotonin reuptake inhibitors have not performed better than placebo in the double blind, placebo controlled trials among pathological gamblers while pharmacological treatments affecting other neurotransmitter systems have performed significantly better than placebo (Westphal 2007).…”