Fixed phone boxes enabling calls to a suicide crisis line have been established at a number of public sites where suicides occur. However, the evidence for the effectiveness of this intervention on suicide deaths is not well established. This study examined the effectiveness of fixed phone boxes by comparing suicide rates during the pre-intervention and post-intervention periods.

Using suicide mortality data from three sites in Australia and three sites in the United States, Poisson regression models were used to estimate incidence rate ratios (IRRs) and 95% confidence intervals (95% CI) at each site. Pooled IRR (pIRR) was then calculated for all sites using a random-effects meta-analysis.

IRRs and 95% CIs at each site were: Australian sites A: 1.32 (0.94–1.85); B: 2.45 (1.52–3.94); C: 0.32 (0.08–1.33); United States sites D: 3.28 (1.46–7.35); E: 0.57 (0.17–1.95); F: 1.65 (0.45–6.10). The pooled IRR was 1.46 (0.86–2.49). Between-site heterogeneity was large, I2 = 66.5%.

Contrary to general expectation, these findings indicate that fixed phone boxes do not reliably reduce suicide mortality, with two sites even showing increased rates after installation. Their impact appears highly inconsistent across locations, providing no consistent evidence of benefit. This suggests that additional or alternative interventions are necessary to achieve meaningful reductions in suicide mortality at high-risk locations.