An important aspect of multiple hypothesis testing is controlling the significance level, or the level of Type I error. When the test statistics are not independent it can be particularly challenging to deal with this problem, without resorting to very conservative procedures. In this paper we show that, in the context of contemporary multiple testing problems, where the number of tests is often very large, the difficulties caused by dependence are less serious than in classical cases. This is particularly true when the null distributions of test statistics are relatively light-tailed, for example, when they can be based on Normal or Student's $t$ approximations. There, if the test statistics can fairly be viewed as being generated by a linear process, an analysis founded on the incorrect assumption of independence is asymptotically correct as the number of hypotheses diverges. In particular, the point process representing the null distribution of the indices at which statistically significant test results occur is approximately Poisson, just as in the case of independence. The Poisson process also has the same mean as in the independence case, and of course exhibits no clustering of false discoveries. However, this result can fail if the null distributions are particularly heavy-tailed. There clusters of statistically significant results can occur, even when the null hypothesis is correct. We give an intuitive explanation for these disparate properties in light- and heavy-tailed cases, and provide rigorous theory underpinning the intuition.Comment: Published in at http://dx.doi.org/10.1214/07-AOS557 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

There are only a few randomized trials of continuation electroconvulsive therapy and maintenance electroconvulsive therapy. The preliminary and limited evidence suggests the modest efficacy of continuation electroconvulsive therapy and maintenance electroconvulsive therapy with concomitant pharmacotherapy in preventing relapse and recurrence of depressive episodes for 1 year after the remission of index episode with the acute course of electroconvulsive therapy.

Australian and New Zealand Clinical Trials Registry ANZCTRN12615000968572. [Katijjahbe MA, Granger CL, Denehy L, Royse A, Royse C, Bates R, Logie S, Nur Ayub MA, Clarke S, El-Ansary D (2018) Standard restrictive sternal precautions and modified sternal precautions had similar effects in people after cardiac surgery via median sternotomy ('SMART' Trial): a randomised trial. Journal of Physiotherapy 64: 97-106].

Individuals with chronic obstructive pulmonary disease (COPD) have demonstrated balance impairment and a higher fall incidence. However, these have not been investigated in acute exacerbations of the disease (ECOPD). This study evaluates balance in patients during an ECOPD compared to stable COPD and healthy controls, and examines the fall incidence rate after hospitalisation due to ECOPD compared to individuals with stable COPD. Balance performance of 26 hospitalised patients with ECOPD was compared to 26 community-dwelling participants with stable COPD and 25 matched healthy controls. Balance was evaluated using computerised posturography and the Berg Balance Scale (BBS). Prospective falls were monitored by monthly calendars for 12 months in both COPD groups. Compared to controls, greater balance impairment was observed during ECOPD for most posturography variables across standing conditions (p ≤ 0.05). Both COPD groups had worse BBS scores (p ≤ 0.05) compared to controls. Increased dyspnoea and reduced quadriceps' strength were associated with impaired balance performance. A higher fall incidence (1.76 falls/person/year) was observed following hospitalisation in patients with ECOPD compared to stable COPD (0.53 falls/person/year) at 12 months. Patients with ECOPD demonstrate balance impairments which are associated with increased dyspnoea and reduced muscle strength. Balance impairment during ECOPD may contribute to a high incidence of falls following hospitalisation.