Accidents happen – and they inflict far more damage and distress on family life than some of the random acts of violence that preoccupy politicians.

About a third of child deaths are the result of accident or misadventure. Drowning is usually the second or third commonest cause after road accidents and, in some countries, the effects of fire. As might be expected, children under five are at highest risk of drowning.

Many prevention and early intervention innovations are complicated. The logic behind them is modeled on an analysis of combinations and entanglements of risk that may lead to impairments to health and development. But other strategies can be astonishingly simple.

Take poolside fencing, for example.

Putting a barrier between younger children and a swimming pool is hardly something to excite politicians or prevention scientists. But it saves more lives than are lost through crimes of violence, at least in the Western World.

A Cochrane Review of this prevention tactic gives grounds for cautious optimism. Diane Thompson, an epidemiologist lately retired from the Harbourview Injury Prevention Center at the University of Washington in Seattle, undertook a systematic review of studies designed to evaluate the prevention properties of pool fencing. She looked for studies of well-defined populations applying objective measures of risk.

Three studies met the criteria. None was a randomized controlled trial. Nevertheless, the indications are that pool fencing reduces the dangers of drowning by about a third.

Evidence of this sort translates into very clear policy and practice advice. The authors recommend fencing around three sides of a pool and separating home pools from the house. There's even advice about the most effective type of gating.

Pool fencing, bicycle helmets, playground safety and a host of other health and safety issues form a small but important part of prevention science. The findings tend to produce largely non-intrusive, low cost proposals that make small, but highly significant impacts on children's health.

See Thompson D. and Rivara F., Pool fencing for preventing drowning in children Cochrane Database of Systematic Reviews, 1998, 1.