A randomized comparison of patients' understanding of number needed to treat and other common risk reduction formats. The effect of alternative summary statistics for communicating risk reduction on decisions about taking statins: a randomized trial. How should the impact of different presentations of treatment effects on patient choice be evaluated? A pilot randomized trial. Health professionals' and service users' interpretation of screening test results: experimental study. Efficacy of repetitive transcranial magnetic stimulation for the treatment of refractory chronic tinnitus: a randomized, placebo controlled study. Reconciling population benefits and women's individual autonomy in mammographic screening: in-depth interviews to explore women's views about 'informed choice'. Use of comparison populations for evaluating the effectiveness of hearing loss prevention programs. A randomized clinical trial of repetitive transcranial magnetic stimulation in the treatment of major depression. Danish GPs' perception of disease risk and benefit of prevention.
Commentators have suggested that patients may understand quantitative information about treatment benefits better when they are presented as numbers needed to treat (NNT) rather than as absolute or relative risk reductions.
                To determine whether NNT helps patients interpret treatment benefits better than absolute risk reduction (ARR), relative risk reduction (RRR), or a combination of all three of these risk reduction presentations (COMBO).
                Randomized cross-sectional survey.
                University internal medicine clinic.
                Three hundred fifty-seven men and women, ages 50 to 80, who presented for health care.
                Subjects were given written information about the baseline risk of a hypothetical "disease Y" and were asked (1) to compare the benefits of two drug treatments for disease Y, stating which provided more benefit; and (2) to calculate the effect of one of those drug treatments on a given baseline risk of disease. Risk information was presented to each subject in one of four randomly allocated risk formats: NNT, ARR, RRR, or COMBO.
                When asked to state which of two treatments provided more benefit, subjects who received the RRR format responded correctly most often (60% correct vs 43% for COMBO, 42% for ARR, and 30% for NNT, P =.001). Most subjects were unable to calculate the effect of drug treatment on the given baseline risk of disease, although subjects receiving the RRR and ARR formats responded correctly more often (21% and 17% compared to 7% for COMBO and 6% for NNT, P =.004).
                Patients are best able to interpret the benefits of treatment when they are presented in an RRR format with a given baseline risk of disease. ARR also is easily interpreted. NNT is often misinterpreted by patients and should not be used alone to communicate risk to patients. While different ways of presenting treatment effects can affect health care decisions, little is known about which presentations best help people make decisions consistent with their own values. We compared six summary statistics for communicating coronary heart disease (CHD) risk reduction with statins: relative risk reduction and five absolute summary measures-absolute risk reduction, number needed to treat, event rates, tablets needed to take, and natural frequencies.
                We conducted a randomized trial to determine which presentation resulted in choices most consistent with participants' values. We recruited adult volunteers who participated through an interactive Web site. Participants rated the relative importance of outcomes using visual analogue scales (VAS). We then randomized participants to one of the six summary statistics and asked them to choose whether to take statins based on this information. We calculated a relative importance score (RIS) by subtracting the VAS scores for the downsides of taking statins from the VAS score for CHD. We used logistic regression to determine the association between participants' RIS and their choice. 2,978 participants completed the study. Relative risk reduction resulted in a 21% higher probability of choosing to take statins over all values of RIS compared to the absolute summary statistics. This corresponds to a number needed to treat (NNT) of 5; i.e., for every five participants shown the relative risk reduction one additional participant chose to take statins, compared to the other summary statistics. There were no significant differences among the absolute summary statistics in the association between RIS and participants' decisions whether to take statins. Natural frequencies were best understood (86% reported they understood them well or very well), and participants were most satisfied with this information.
                Presenting the benefits of taking statins as a relative risk reduction increases the likelihood of people accepting treatment compared to presenting absolute summary statistics, independent of the relative importance they attach to the consequences. Natural frequencies may be the most suitable summary statistic for presenting treatment effects, based on self-reported preference, understanding of and satisfaction with the information, and confidence in the decision.
                ISRCTN85194921. Different presentations of treatment effects can affect decisions. However, previous studies have not evaluated which presentations best help people make decisions that are consistent with their own values. We undertook a pilot study to compare different methods for doing this.
                We conducted an Internet-based randomized trial comparing summary statistics for communicating the effects of statins on the risk of coronary heart disease (CHD). Participants rated the relative importance of treatment consequences using visual analogue scales (VAS) and category rating scales (CRS) with five response options. We randomized participants to either VAS or CRS first and to one of six summary statistics: relative risk reduction (RRR) and five absolute measures of effect: absolute risk reduction, number needed to treat, event rates, tablets needed to take, and natural frequencies (whole numbers). We used logistic regression to determine the association between participants' elicited values and treatment choices. 770 participants age 18 or over and literate in English completed the study. In all, 13% in the VAS-first group failed to complete their VAS rating, while 9% of the CRS-first group failed to complete their scoring (p = 0.03). Different ways of weighting the elicited values had little impact on the analyses comparing the different presentations. Most (51%) preferred the RRR compared to the other five summary statistics (1% to 25%, p = 0.074). However, decisions in the group presented the RRR deviated substantially from those made in the other five groups. The odds of participants in the RRR group deciding to take statins were 3.1 to 5.8 times that of those in the other groups across a wide range of values (p = 0.0007). Participants with a scientific background, who were more numerate or had more years of education were more likely to decide not to take statins.
                Internet-based trials comparing different presentations of treatment effects are feasible, but recruiting participants is a major challenge. Despite a slightly higher response rate for CRS, VAS is preferable to avoid approximation of a continuous variable. Although most participants preferred the RRR, participants shown the RRR were more likely to decide to take statins regardless of their values compared with participants who were shown any of the five other summary statistics.
                Controlled-Trials.com ISRCTN85194921. To investigate the accuracy of interpretation of probabilistic screening information by different stakeholder groups and whether presentation as frequencies improves accuracy.
                Between participants experimental design; participants responded to screening information embedded in a scenario.
                Regional maternity service and national conferences and training days.
                43 pregnant women attending their first antenatal appointment in a regional maternity service; 40 companions accompanying the women to their appointments; 42 midwives; 41 obstetricians. Participation rates were 56%, 48%, 89%, and 71% respectively.
                Participants estimated the probability that a positive screening test result meant that a baby actually had Down's syndrome on the basis of all the relevant information, which was presented in a scenario. They were randomly assigned to scenarios that presented the information in percentage (n = 86) or frequency (n = 83) format. They also gave basic demographic information and rated their confidence in their estimate.
                Most responses (86%) were incorrect. Obstetricians gave significantly more correct answers (although still only 34% [corrected]) than either midwives (0%) or pregnant women (9%). Overall, the proportion of correct answers was higher for presentation as frequencies (24%) than for presentation as percentages (6%), but further analysis showed that this difference occurred only in responses from obstetricians. Many health professionals were confident in their incorrect responses.
                Most stakeholders in pregnancy screening draw incorrect inferences from probabilistic information, and health professionals need to be aware of the difficulties that both they and their patients have with such information. Moreover, they should be aware that different people make different mistakes and that ways of conveying information that help some people will not help others. The pathophysiologic mechanisms of idiopathic tinnitus remain unclear. Low frequency rTMS applied over the auditory cortex has been proposed as a new and causally oriented treatment approach for pathological conditions with abnormal, increased cortical activity including tinnitus with increased activity in the auditory cortex. However available studies are characterized by a positive reports on the therapeutic effects of repetitive transcranial magnetic stimulation (rTMS) for treatment of tinnitus, there are few details about the duration of specific treatment effects.
                The design of the study was randomized, prospective, placebo-controlled. Right-handed patients were treated with either real or sham 1 Hz frequency rTMS over a period of two weeks. Fifty-two patients with chronic, treatment resistant tinnitus and stable medication were enrolled in the study after giving written informed consent and forty-two patients completed the study and were included in data analysis.
                The ability to reduce the symptoms of tinnitus appeared in both randomized groups immediately after the 1 Hz rTMS and sham stimulation phase. There was a significant reduction in both groups of the tinnitus total score on the Tinnitus Handicap Inventory (THI) (real rTMS p=0.005; sham rTMS p=0.049) and Tinnitus Questionnaire (TQ) total score (real rTMS p=0.003; sham rTMS p=0.049). On the THI evaluation scale, in the real rTMS a mild worsening was noted during week 6 in comparison with the state attained in week 2. During the subsequent course of the study a significant reduction of the total score persisted in the case of THI (real rTMS week 14 p=0.033 and borderline week 26 p=0.058). The reduction of symptoms as evaluated using the TQ was significant compared to baseline in the real rTMS group at week 2, 6 and 14 (p=0.003; p=0.024; p=0.022). The group treated with sham stimulation reached significant reduction of symptoms only at week 2 (p=0.049). A comparison of the difference in the recorded values of the total score during follow-up in relation to baseline expressed as a percentage demonstrates the difference in the effect of rTMS and sham stimulation as evaluated by both the basic scales. Graphical analysis of mean patterns of treatment response according to stimulation type shows a similarity between treatment response patterns evaluated by reduction of the total scores using THI and TQ.
                The principal finding of this study is that real 1 Hz rTMS treatment was capable of significantly reducing the total baseline score of basic scales that measure tinnitus severity. This result is important as it proves that significant reduction of symptoms can be achieved even in a group of patients with long-term symptoms resistant to pharmacological treatment. To explore women's reactions to 'informed choice' in mammographic screening.
                Telephone interviews with a convenience sample of 106 women aged 45-70 years recruited from general practices in Sydney.
                Many (42%) women preferred an active role in decision-making. Respondents had low scores for 'uncertainty' and 'factors contributing to uncertainty' in response to explicit questions about the decision to have mammographic screening. Yet respondents indicated significantly greater willingness to have a test when the benefit of a 'new' screening test for breast cancer was expressed as relative risk reduction (RRR) (88%) than either absolute risk reduction (ARR) (78%) (McNemar's test: chi(2)1=7.14, p=0.013) or all-cause mortality (53%) (McNemar's test: chi(2)1=35.1, p<0.01). Significantly more respondents considered information about ARR 'new' to them (65%) compared with RRR information (30%) (McNemar's test: chi(2)1=25.83, p<0.01).
                As mammographic screening exposes well women to potential harms for an overall population benefit, it is challenging to ensure 'informed choice'. Our results suggest women will likely appreciate individual consultations as the context in which to share complex information that women in our study agreed they need to know about mammographic screening. Our results also demonstrate that women's willingness as individuals to participate in mammographic screening is influenced by 'framing effect'. Hence, the quantitative content of decision aids to promote 'informed choice' must be comprehensive and balanced. One approach for evaluating the effectiveness of Hearing loss prevention programs (HLPPs) is to compare the rate of hearing loss in a study population with that in a reference population. This approach was used to evaluate the HLPP of a population of 14,900 employees of an industrial company with branches across the United States. Three reference populations were selected from a database of 22 industrial companies compiled under the sponsorship of the National Institute for Occupational Safety and Health. The risk of hearing loss in the study population was estimated relative to each of the three reference populations using the Cox proportional hazards model after adjustment for race, age at baseline, and hearing threshold at time of enrollment in the HLPP. In comparison with the three reference populations, hearing loss was 2.1 to 3.9 times more likely to occur in study population males and 1.8 to 5.1 times more likely in study population females. The 95% confidence interval around each risk estimate precluded unity, indicating that each risk estimate was statistically significant. These results indicate that the performance of the subject HLPP needs improvement. This study demonstrated the use of comparison populations for evaluating the effectiveness of HLPPs. Multiple groups have reported on the use of repetitive transcranial magnetic stimulation (rTMS) in treatment-resistant major depression. The purpose of this study is to assess the efficacy of rTMS in unmedicated, treatment-resistant patients who meet criteria for major depression.
                Depressed subjects, who had failed to respond to a median of four treatment trials, were assigned in a randomized double-blind manner to receive either active (n = 10; 20 2-sec trains of 20 Hz stimulation with 58-sec intervals; delivered at 80% motor threshold with the figure-of-eight coil positioned over the left dorsolateral prefrontal cortex) or sham (n = 10; similar conditions with the coil elevated and angled 45 degrees tangentially to the scalp) rTMS. These sequences were applied during 10 consecutive weekdays. Continuous electroencephalogram sampling and daily motor threshold determinations were also obtained.
                The group mean 25-item Hamilton Depression Rating Scale (HDRS) score was 37.2 (+/- 2.0 SEM) points. Adjusted mean decreases in HDRS scores were 14.0 (+/- 3.7) and 0.2 (+/- 4.1) points for the active and control groups, respectively (p <.05). One of 10 subjects receiving active treatment demonstrated a robust response (i.e., HDRS decreased from 47 to 7 points); three other patients demonstrated 40-45% decreases in HDRS scores. No patients receiving sham treatment demonstrated partial or full responses.
                A 2-week course of active rTMS resulted in statistically significant but clinically modest reductions of depressive symptoms, as compared to sham rTMS in a population characterized by treatment resistance. Uncertainty and risk are central issues in relation to health and health care services. Healthy individuals do not necessarily fall ill, despite the presence of risk factors. It has been documented that doctors, health service administrators and patients are more inclined to choose interventions against risk factors when information about the effects is presented in terms of relative risk reductions rather than absolute risk reductions.
                The objective of the study was to gain better insight into how GPs perceive risk of disease, and how this perception is influenced by the way the risk is presented, e.g. whether changes in risk are presented in absolute or relative terms.
                Questionnaires with clinical episodes were sent to 1500 Danish GPs. The GPs were randomized into four groups of 375, who all received the same case story with information about risk reduction achieved through medical treatment phrased in terms of either relative risk reduction, absolute risk reduction, number needed to treat or all of the aforementioned terms of risk reduction. The GPs were asked whether they would recommend medical treatment as primary prevention, knowing the case story and expected risk reduction.
                The GPs' attitude towards recommending medical treatment was dependent on the phrasing of risk reductions. Seventy-two per cent of doctors who received all information on risk reductions would definitely or probably recommend medication, while 91% would recommend medication if information only about relative risk reduction was given, and 63% would recommend medication if information was given in terms of absolute risk reduction or number needed to treat.
                In order to advise patients in a rational way, in addition to knowledge of the patients' preferences, doctors need to take into account all available measures of risk reductions.
Natural frequencies are probably better understood than percentages in the context of diagnostic or screening tests. For communicating risk reductions, relative risk reduction (RRR), compared with absolute risk reduction (ARR) and number needed to treat (NNT), may be perceived to be larger and is more likely to be persuasive. However, it is uncertain whether presenting RRR is likely to help people make decisions most consistent with their own values and, in fact, it could lead to misinterpretation. More research is needed to further explore this question.