A population based study of the prevalence of pain in Iceland.

Prevalence estimates of pain differ depending on how it is defined and measured and on the populations studied. It has been estimated that on a given day, as many as 30-44% of the general population experience some kind of pain. Information about the prevalence of pain in Iceland is not available. The aims of this study were to evaluate the prevalence of pain of various origins among the general population of Iceland, to test hypotheses regarding relationships between pain, quality of life (QOL) and demographic variables, to evaluate participants' beliefs about causes of their pain, and to evaluate how those who experience pain manage it. A random sample of 1286 adults was drawn from a national registry holding information about all citizens of Iceland. Data were collected with a postal-survey. Pain was evaluated with the Brief Pain Inventory (BPI), with instructions modified to evaluate pain in the past week as opposed to the past 24 h. Of 1286 invited, 599 (46.6%) participated, of which, 232 had experienced pain in the past week (40.3%). Participants had a mean (SD) age of 44.94 (17.12) years and 56% were women. Those who had pain perceived their health to be worse than those who had not [B = -0.91, SE = 0.15, Wald = 38.75, p = 0.00], but did not differ on other variables. Of 232 individuals reporting pain, 183 (79.6%) or 30.6% of the total sample had experienced pain for more than three months. On a scale from 0 "no pain" to 10 "pain as bad as I can imagine" the mean (SD) pain severity score (composite of four pain severity scores) for the 232 participants reporting pain was 3.21 (1.73) and pain interference with life activities 2.59 (1.98), also on a 0-10 scale. Pain severity predicted pain interference [B = 0.71; F = 126.14; df = 1,206; p = 0.00], which mediated the effects of pain severity on mood and QOL. Between Pain Interference with Life and Positive Affect [B = -0.06; F = 4.53; df = 1,196; p = 0.04], between Pain Interference and Negative Affect [B = 0.15; F = 23.21; df = 1,196; p = 0.00], and between Pain Interference and Global Quality of Life [B = -0.18; F = 29.11; df = 1,196; p = 0.00]. Most frequent causes for pain were strain injuries (n = 79), resulting from work or sports activity, arthritis (n = 39), mechanical problems (e.g. due to birth defects, curvature, slipped discs, etc.) (n = 37), various diseases (n = 31) and accidents (n = 30). Nineteen participants did not know what caused their pain. Treatments for pain varied, but most had used medications alone (n = 76) or in combination with other treatments (n = 61). The prevalence of pain in the general population of Icelandic adults is similar to what has been reported. Estimates of chronic pain are towards the higher end when compared to data from other European counties, yet comparable to countries such as Norway. This raises questions about possible explanations to be looked for in genetics or cultural point of view. This population based study provides valuable information about the prevalence of pain in Iceland and also supports findings previously reported about pain in the neighboring countries.