Do statisticians count? A prior and posterior viewpoint.

In this article we look back over the last few decades and consider the progress made against the barriers that Andy Grieve has identified that may be holding statisticians back. We highlight some examples from his career where he leads the way in showing how we may overcome obstacles to enable statisticians to 'count' and assess whether anything has now changed for pharmaceutical statisticians.

A case study using the PrOACT-URL and BRAT frameworks for structured benefit risk assessment.

While benefit-risk assessment is a key component of the drug development and maintenance process, it is often described in a narrative. In contrast, structured benefit-risk assessment builds on established ideas from decision analysis and comprises a qualitative framework and quantitative methodology. We compare two such frameworks, applying multi-criteria decision-analysis (MCDA) within the PrOACT-URL framework and weighted net clinical benefit (wNCB), within the BRAT framework. These are applied to a case study of natalizumab for the treatment of relapsing remitting multiple sclerosis. We focus on the practical considerations of applying these methods and give recommendations for visual presentation of results. In the case study, we found structured benefit-risk analysis to be a useful tool for structuring, quantifying, and communicating the relative benefit and safety profiles of drugs in a transparent, rational and consistent way. The two frameworks were similar. MCDA is a generic and flexible methodology that can be used to perform a structured benefit-risk in any common context. wNCB is a special case of MCDA and is shown to be equivalent to an extension of the number needed to treat (NNT) principle. It is simpler to apply and understand than MCDA and can be applied when all outcomes are measured on a binary scale.

Frequency of use of household products containing VOCs and indoor atmospheric concentrations in homes.

Volatile organic compounds (VOCs) are a key class of atmospheric emission released from highly complex petrochemical, transport and solvent sources both outdoors and indoors. This study established the concentrations and speciation of VOCs in 60 homes (204 individuals, 360 × 72 h samples, 40 species) in summer and winter, along with outdoor controls. Self-reported daily statistics were collected in each home on the use of cleaning, household and personal care products, all of which are known to release VOCs. Frequency of product use varied widely: deodorants: 2.9 uses home per day; sealant-mastics 0.02 uses home per day. The total concentration of VOCs indoors (range C2-C10) was highly variable between homes e.g. range 16.6-8150 µg m-3 in winter. Indoor concentrations of VOCs exceeded outdoor for 84% of households studied in summer and 100% of homes in winter. The most abundant VOCs found indoors in this study were n-butane (wintertime range: 1.5-4630 µg m-3), likely released as aerosol propellant, ethanol, acetone and propane. The cumulative use VOC-containing products over multiday timescales by occupants provided little predictive power to infer 72 hour averaged indoor concentrations. However, there was weak covariance between the cumulative usage of certain products and individual VOCs. From a domestic emissions perspective, reducing the use of hydrocarbon-based aerosol propellants indoors would likely have the largest impact.

Efficacy and safety of sildenafil citrate in women with sexual dysfunction associated with female sexual arousal disorder.

OBJECTIVE: Sildenafil citrate (Viagra Pfizer, New York, NY) is indicated for the treatment of erectile dysfunction in men. The nitric oxide-cyclic guanosine monophosphate pathway (NO-cGMP) involved in penile erection and enhanced by sildenafil may also play a role in some components of the female sexual arousal response. The efficacy and safety of sildenafil were evaluated in estrogenized and estrogen-deficient women with sexual dysfunction that included female sexual arousal disorder (FSAD). METHODS: Patients were randomized to receive 10-100 mg sildenafil or matching placebo. To assess efficacy, patients completed two global efficacy questions (GEQ), the Life Satisfaction Checklist (LSC), an event log of sexual activity, and a 31-item sexual function questionnaire (SFQ). To assess safety, adverse event (AE) data were recorded. RESULTS: A total of 577 estrogenized and 204 estrogen-deficient women were randomized to treatment. All were diagnosed with FSAD, but it was the primary presenting symptom in only 46% and 50% of women, respectively. Differences in efficacy between sildenafil and placebo were not significant for any patient or partner end points (e.g., the two GEQ, the sexual event logs, the LSC, and the SFQ). The main AE were headache, flushing, rhinitis, nausea, visual disturbances, and dyspepsia, which were generally mild to moderate in nature. CONCLUSIONS: Any genital physiological effect of sildenafil was not perceived as improving the sexual response in estrogenized or estrogen-deficient women with a broad spectrum of sexual dysfunction that included FSAD. Whether more specific subgroups of women with FSAD could potentially benefit from treatment with sildenafil is an area for future research.