Comparison of whole-head and split-head design for the clinical evaluation of anti-dandruff shampoo efficacy.

OBJECTIVE: Dandruff is a common scalp condition that can be improved by regular use of shampoos containing anti-fungal actives. The efficacy of anti-dandruff shampoos can be assessed by measuring scalp flaking, one of the important dandruff symptoms. A randomized, double-blind trial is often used with one of two clinical designs: whole-head parallel design and split-head paired design. We aimed to explore the difference in product differentiation between these two designs using the same two test shampoos and the same scalp flaking assessment method (Total Weighted Head Score Adhered Flakes-TWHS AF). METHODS: A clinical study was conducted with a 2- to 3-week wash-out phase and a 4-week test phase, consisting of 2 cells: 120 subjects with whole-head parallel design, divided into 2 subgroups (1:1) using on-site controlled washing method (either wash their own hair at a study site, under the instruction of a study supervisor or wash their own hair at home, as per instructions, but without supervision) and 35 subjects with split-head paired design using salon-staff washing method. Both cells employed hair washing at frequency of three times a week and TWHS AF measurement once a week from the baseline assessment. RESULTS: Both designs gave similar differences in TWHS AF between products: 5.6 units (95% CI: 4.1-7.0 units) in whole-head design and 5.9 units (95% CI: 4.9-6.9 units) in split-head design. CONCLUSION: Split-head paired design shows a similar ability of detecting product difference as whole-head parallel design, whereas it is a choice of more efficient and more cost-effective, as only a quarter of the subjects are required to demonstrate the efficacy between anti-dandruff shampoos.

OBJECTIF: Les pellicules sont une affection courante du cuir chevelu qui peut être améliorée par l'utilisation régulière de shampooings contenant des principes actifs antifongiques. L'efficacité des shampooings antipelliculaires peut être évaluée en mesurant la desquamation du cuir chevelu, l'un des symptômes importants associés aux pellicules. Il est souvent fait recours à une étude randomisée et en double aveugle reposant sur l'une des deux conceptions cliniques suivantes: une conception parallèle portant sur la tête entière et une conception appariée par séparation de la surface de la tête. Nous avons cherché à étudier en quoi des produits se différenciaient entre ces deux conceptions, en utilisant les deux mêmes shampooings d'examen et la même méthode d'évaluation de la desquamation du cuir chevelu (score total pondéré des pellicules collées sur la tête [Total Weighted Head Score Adhered Flakes, TWHS AF]). MÉTHODES: Une étude clinique a été menée avec une fenêtre thérapeutique de deux à trois semaines et une phase d'examen de quatre semaines, composée de deux cellules: 120 sujets recrutés selon une conception parallèle portant sur la tête entière, répartis en deux sous-groupes (1:1), avec un lavage réalisé au centre d'après une méthode contrôlée (lavage par le sujet dans l'un des centres de l'étude, réalisé sous les instructions d'un superviseur de l'étude, ou lavage par le sujet à son domicile, en suivant les instructions, mais sans surveillance) et 35 sujets recrutés selon une conception appariée par séparation de la surface de la tête, avec un lavage réalisé selon la méthode employée par le personnel des salons de coiffure. Pour les deux cellules, le lavage des cheveux avait lieu à une fréquence de trois fois par semaine et le score TWHS AF était mesuré une fois par semaine à partir de l'évaluation de référence. RÉSULTATS: Les deux conceptions ont permis d'observer des différences similaires des scores TWHS AF entre les produits: 5,6 unités (IC à 95%: 4,1 à 7,0 unités) avec la conception portant sur la tête entière et 5,9 unités (IC à 95%: 4,9 à 6,9 unités) avec la conception par séparation de la surface de la tête. CONCLUSION: Par comparaison avec la conception parallèle portant sur la tête entière, la conception appariée par séparation de la surface de la tête montre une capacité de détection similaire de la différence entre les produits, mais constitue un choix plus efficace et plus rentable, car elle n'exige de démontrer l'efficacité entre les shampooings antipelliculaires que chez un quart des sujets.

A randomised controlled trial investigating efficacy of a novel toothpaste containing calcium silicate and sodium phosphate in dentine hypersensitivity pain reduction compared to a fluoride control toothpaste.

OBJECTIVES: To compare a calcium silicate and sodium phosphate toothpaste (CSSP) with a fluoride negative control toothpaste for dentine hypersensitivity (DH) pain reduction after 14, 28 and 29 days. METHODS: This was a double blind, parallel study in 247 healthy adults with DH (Schiff score >2, tactile 10-20 g) in 2 teeth in different quadrants of the mouth. After acclimatisation, participants were randomised to CSSP or control toothpaste. After measuring baseline sensitivity products were applied twice-daily by toothbrushing, and once daily massaging into the sensitive teeth. Sensitivity was assessed following airblast (Schiff and VAS) and tactile (Yeaple probe) stimuli at baseline, 14 and 28 days, and at 29 days, 12 h after last product application. Participants completed a quality of life questionnaire at each study visit up to day 28. RESULTS: After 14, 28 and 29 days the CSSP group had significantly lower Schiff, lower VAS and higher Yeaple probe scores compared to control (VAS at 14 days, p < 0.04; all other comparisons, p < 0.001). Quality of life scores improved in both groups, but no significant differences between groups were observed. CONCLUSIONS: The CSSP toothpaste was more effective than the fluoride control toothpaste at reducing DH pain with benefit persisting 12 h following application. CLINICAL SIGNIFICANCE: This novel calcium silicate and sodium phosphate toothpaste (CSSP) toothpaste is an effective twice-daily treatment when brushed on the teeth for dentine hypersensitivity sufferers compared to brushing with a conventional fluoride paste. Twice-daily brushing provides a sustained effect for long-lasting pain relief from dentine hypersensitivity.

A high glycerol-containing leave-on scalp care treatment to improve dandruff.

Dandruff is a common cosmetic condition associated with flaky scalp skin and pruritus. It is generally treated with regular use of antifungal-based shampoos. Research into factors underlying the characteristic skin lesions has revealed perturbations in epidermal differentiation and a dramatic deterioration in the associated process of stratum corneum (SC) maturation. These observations suggest that directly addressing the quality of the SC could have a scalp benefit. In this study, the authors investigated the efficacy of a moisturising leave-on lotion (LOL) containing a high concentration of glycerol (10%) and other known skin benefit agents (saturated fatty acid and sunflower seed oil) to reduce dandruff over an 8-week treatment period with 3 applications per week. Results of expert visual grading and biophysical measurements of SC parameters (transepidermal water loss and hydration) revealed a significant reduction in the dandruffcondition over this period, with significant improvement in both SC water barrier function and hydration. These scalp skin benefits were maintained for up to a week following cessation of the treatment. This study indicates that use of a glycerol-rich substantive LOL, designed to directly improve the quality of the SC barrier can have a significant impact on the dandruff condition.

An investigation of the effects of a hand washing intervention on health outcomes and school absence using a randomised trial in Indian urban communities.

OBJECTIVES: To evaluate how an intervention, which combined hand washing promotion aimed at 5-year-olds with provision of free soap, affected illnesses among the children and their families and children's school absenteeism. METHODS: We monitored illnesses, including diarrhoea and acute respiratory infections (ARIs), school absences and soap consumption for 41 weeks in 70 low-income communities in Mumbai, India (35 communities per arm). RESULTS: Outcomes from 847 intervention households (containing 847 5-year-olds and 4863 subjects in total) and 833 control households (containing 833 5-year-olds and 4812 subjects) were modelled using negative binomial regression. Intervention group 5-year-olds had fewer episodes of diarrhoea (-25%, 95% confidence intervals [CI] = -37%, -2%), ARIs (-15%, 95% CI = -30%, -8%), school absences due to illnesses (-27%, 95% CI = -41%, -18%) and eye infections (-46%, 95% CI = -58%, -31%). Further, there were fewer episodes of diarrhoea and ARIs in the intervention group for 'whole families' (-31%, 95% CI = -37%, -5%; and -14%, 95% CI = -23%, -6%, respectively), 6- to 15-year-olds (-30%, 95% CI = -39%, -7%; and -15%, 95% CI = -24%, -6%) and under 5 s (-32%, 95% CI = -41%, -4%; and -20%, 95% CI = -29%, -8%). CONCLUSIONS: Direct-contact hand washing interventions aimed at younger school-aged children can affect the health of the whole family. These may be scalable through public-private partnerships and classroom-based campaigns. Further work is required to understand the conditions under which health benefits are transferred and the mechanisms for transference.