Pain-related fear in acute low back pain: the first two weeks of a new episode.

The overall aim of this study was to explore the natural course of pain-related fear during the early stage of a new low back pain episode, using a prospective case series design. Specific research questions addressed the existence of typical patterns in individual time series of pain-related fear and sequential relationships between the occurrence of pain-related fear, pain and pain catastrophizing. Forty-four general practice patients who consulted their physician with a new episode of non-specific low back pain were recruited. They completed diaries on pain-related fear, pain and pain catastrophizing for 14 days following the consultation. Follow-up questionnaires on disability were completed at 3 months and 12 months. Time series analyses produced subgroups of patients with descending, stable and rising levels of pain-related fear over the 2-week period. These groups differed on baseline characteristics and outcome at follow-up. A time-shift between the occurrence of pain-events and pain-related fear or pain catastrophizing could not be demonstrated.In summary, these results fit in with previous findings in chronic patients. A relevant subgroup of patients who might benefit from early intervention could be identified. These findings support the need for further research into fear mechanisms in acute low back pain.