Examining clinical trial results with single-subject analysis: an example involving behavioral and nutrition treatment for young children with cystic fibrosis.

OBJECTIVE: To examine the process of change in a clinical trial of behavioral and nutrition treatment for children age 18-48 months with cystic fibrosis (CF) using single-subject analysis. METHODS: The 5-week treatment included nutrition counseling and child behavioral management training for parents and was designed to increase energy intake measured by diet diaries 600-800 calories per day. RESULTS: Energy intake changed at each meal, only when treatment was introduced (week 1: snacks, 420 to 691; week 2: breakfast, 325 to 443; week 4: lunch, 350 to 443; and week 5: dinner, 373 to 460 calories per day). Total daily intake increased in a systematic fashion that exceeded the criterion set each week during treatment. CONCLUSIONS: Toddlers and preschoolers with CF meet energy intake recommendations as a result of behavioral intervention. Single-subject research designs are important methodologies for advancing clinical investigation in pediatric psychology.

Randomized clinical trial of behavioral and nutrition treatment to improve energy intake and growth in toddlers and preschoolers with cystic fibrosis.

OBJECTIVE: To conduct a randomized clinical trial comparing a behavioral and nutrition intervention (BEH) with a usual care control condition (CTL) for children (ages 18 months to 4 years) with cystic fibrosis (CF) and pancreatic insufficiency. This trial was designed to (1) evaluate a randomized comparison of BEH with CTL over 8 weeks, (2) provide a replication of the impact of BEH by inviting the CTL group to receive BEH after 8 weeks, and (3) examine the maintenance of BEH at 3- and 12-month follow-up. METHODS: Of 14 eligible children, 10 were randomly assigned and initiated treatment (71% recruitment rate). Four participants were randomly assigned to BEH, and 6 were assigned to CTL (5 of whom chose to crossover to BEH). BEH included nutrition counseling to increase energy intake (via types of foods and addables/spreadables) and child behavioral management training to teach parents differential attention and contingency management skills. CTL was consistent with the 2002 CF Foundation Consensus Conference Guidelines for nutritional care. RESULTS: BEH led to greater increases in energy intake pre- to posttreatment than CTL as measured by calories per day (842 kcal/day vs -131 kcal/day change). On receiving BEH, the change in energy intake was replicated with the CTL group (892 kcal/day change). At 3- and 12-month follow-up, energy intake was maintained (672 kcal/day increase from baseline and 750 kcal/day increase from baseline, respectively). Children in this study met or exceeded normal weight and height velocities from pretreatment to the 3-month follow-up (mean weight: 1.4 kg/6 months; mean height: 5.1 cm/6 months) and from posttreatment to the 12-month follow-up (mean weight: 2.5 kg/12 months; mean height: 8.3 cm/12 months). CONCLUSIONS: Toddlers and preschoolers who have CF and received BEH were able to meet the energy intake recommendations for this disease and maintain these gains up to 12 months after treatment. In addition, these children demonstrated weight and height velocities from pretreatment to 12-month follow-up, consistent with the goal of normal growth. BEH is a promising, evidence-based, early nutritional intervention for children with CF. An upcoming multisite clinical trial will test BEH versus an attention control condition using a larger sample (N = 100), providing additional evidence about the efficacy of this treatment for energy intake and growth in young children with CF.

Predicting the crystallization potential of urine from cats and dogs with respect to calcium oxalate and magnesium ammonium phosphate (struvite).

The objective of this study was to validate two programs (SUPERSAT and EQUIL 2) for calculation of calcium oxalate (CaOx) and magnesium ammonium phosphate (struvite; MAP) relative supersaturation (RSS) in dog and cat urine. Healthy adult cats (n = 10) and dogs (n = 9) were fed standard diets for a 3-wk period. Urine was collected (24 h, dogs; 48 h, cats) and filtered, and the pH was measured. A 20-mL aliquot was titrated to pH 2 and frozen for analysis. Additional aliquots were incubated with 1 g seed crystals at 38 degrees C; CaOx for 24 h (cat) and 2, 6 and 9 d (dog); MAP for 48 h (dog) and 6 d (cat). Samples were analyzed for 10 substances. RSS was calculated using EQUIL 2 and SUPERSAT. CaOx RSS (SUPERSAT): dog urine was initially supersaturated, whereas cat urine was undersaturated with the diets used. Cat urine reached the solubility product (K(sp)), (RSS = 1) after 24-h incubation, whereas dog urine was still approaching K(sp) at 9 d. MAP RSS (SUPERSAT): urine from both species was undersaturated and increased toward K(sp) during incubation. Final RSS values were compared for both programs. SUPERSAT resulted in values close to 1 for both CaOx and MAP; EQUIL 2 gave similar values for CaOx RSS, although MAP RSS values were considerably higher than 1. In conclusion, EQUIL 2 and SUPERSAT both calculated reasonably accurate RSS values for CaOx, whereas only SUPERSAT provided an accurate measure of MAP RSS.