Incidence

Estimating the incidence of low back pain is problematic as the cumulative incidence of first-ever episodes of low back pain is already high by early adulthood and symptoms tend to recur over time . In addition, longitudinal studies, which measure incidence, are more expensive than cross-sectional studies, which measure prevalence. As a result, there is a significant amount of literature on the prevalence of low back pain, but much less information on low back pain incidence and remission.

In our systematic review of incidence, 12 studies met the inclusion criteria and underwent data extraction. Of these, four were considered to have a low risk of bias , four a moderate risk of bias and four a high risk of bias . Case definitions varied between these studies. Most measured pain in the ‘low back’ and three studied the ‘back’ . Most did not specify a minimum episode duration that was required for a case to be counted; four required a minimum episode duration of 1 day and one study required a period of 6 months .

Incidence was most commonly measured over 1 year. Other follow-up periods included 6 months , 2 years , 3 years and 5 years . Four of the studies limited their focus to first-ever episodes of low back pain , while the remainder of studies measure all episodes (i.e., first-ever and recurrent). All of the studies counted the number of people with an episode of low back pain as opposed to the number of episodes. The 1 year incidence of people who have a first-ever episode of low back pain ranged from 6.3% to 15.4%, and the 1 year incidence of people who have any episode of low back pain (i.e., first-ever or recurrent) ranged from 1.5% to 36% ( Table 1 ). As these studies did not include repeat episodes in the period of interest, they are likely to underestimate episode incidence.

Remission

For estimating the burden of disease in GBD 2005, remission is defined as the rate at which people stop having the disease or condition, and is expressed as an annual hazard rate to recover from the disease. In many instances, people with activity-limiting low back pain will go on to have recurrent episodes that may be longer in duration and associated with greater disability . Consequently, the course of low back pain is increasingly viewed as a chronic, recurrent condition that may have one of several trajectories , replacing previous categorisations of low back pain as being either acute, subacute or chronic in nature. Thus, in the majority of cases, true remission in the sense that a single episode of low back pain never recurs, is rare. Furthermore, many people will continue to have symptoms and/or disability between episodes. Recent research investigating the meaning of remission from the patient’s perspective found that many patients continue to suffer between episodes but change what they do to manage the potential for recurrence .

For the systematic review of low back pain remission, we were unable to identify any population-based studies that met our inclusion criteria and provided relevant information on the remission of low back pain. We therefore broadened our inclusion criteria to include study populations derived from clinic or health facilities. In total, we identified seven health facility- or clinic-based studies. Of these, two were considered moderate risk of bias and five high risk of bias . All studies were from high-income countries. Six measured remission of pain in the ‘low back’ region, and one measured remission in the ‘lumbar’ region . Only one of the seven studies had a minimum episode duration required for cases to be counted – ‘at least one day’ . Three of the studies focussed on activity-limiting low back pain and the other four studies measured remission of all low back pain, whether activity-limiting or not. All studies measured remission of first-ever and recurrent episodes combined.

The average time between onset of pain and consultation was unclear in most of the studies making it difficult to accurately estimate the time to remission. Most studies did not indicate whether the episode was continuous between the baseline and follow-up time point(s). Given the chronic–episodic nature of low back pain and the high rate of recurrence, this is an important consideration. If cases have asymptomatic phases between these points, remission may be underestimated. Remission at 1 year was measured in two studies and ranged from 54% to 90% ( Table 2 ).

Remission

For estimating the burden of disease in GBD 2005, remission is defined as the rate at which people stop having the disease or condition, and is expressed as an annual hazard rate to recover from the disease. In many instances, people with activity-limiting low back pain will go on to have recurrent episodes that may be longer in duration and associated with greater disability . Consequently, the course of low back pain is increasingly viewed as a chronic, recurrent condition that may have one of several trajectories , replacing previous categorisations of low back pain as being either acute, subacute or chronic in nature. Thus, in the majority of cases, true remission in the sense that a single episode of low back pain never recurs, is rare. Furthermore, many people will continue to have symptoms and/or disability between episodes. Recent research investigating the meaning of remission from the patient’s perspective found that many patients continue to suffer between episodes but change what they do to manage the potential for recurrence .

For the systematic review of low back pain remission, we were unable to identify any population-based studies that met our inclusion criteria and provided relevant information on the remission of low back pain. We therefore broadened our inclusion criteria to include study populations derived from clinic or health facilities. In total, we identified seven health facility- or clinic-based studies. Of these, two were considered moderate risk of bias and five high risk of bias . All studies were from high-income countries. Six measured remission of pain in the ‘low back’ region, and one measured remission in the ‘lumbar’ region . Only one of the seven studies had a minimum episode duration required for cases to be counted – ‘at least one day’ . Three of the studies focussed on activity-limiting low back pain and the other four studies measured remission of all low back pain, whether activity-limiting or not. All studies measured remission of first-ever and recurrent episodes combined.

The average time between onset of pain and consultation was unclear in most of the studies making it difficult to accurately estimate the time to remission. Most studies did not indicate whether the episode was continuous between the baseline and follow-up time point(s). Given the chronic–episodic nature of low back pain and the high rate of recurrence, this is an important consideration. If cases have asymptomatic phases between these points, remission may be underestimated. Remission at 1 year was measured in two studies and ranged from 54% to 90% ( Table 2 ).

Duration

We conducted an abbreviated search of the literature and found a small number of cohort studies that estimated low back pain duration. Similar to remission, we found the only useful studies were health facility- or clinic-based. Again, there was substantial heterogeneity between studies. Many of the studies reported the proportion of people with pain at a certain time point , which is reported on in the remission section above. Van den Hoogen found the median duration of pain from the index episode was 42 days . Von Korff found that the median pain days at 1 year follow-up was 15.5 days in those patients whose low back pain lasted less than 3 months from baseline, and 128.5 days in those patients whose low back pain lasted between 3 and 6 months from baseline .

Recurrence

The natural history of low back pain has been observed to be extremely variable and may last a few days or persist for many years . Most commonly, people who experience activity-limiting low back pain lasting more than 1 day go on to have recurrent episodes . Wasiak et al. (2006) found that low back pain recurrence contributed disproportionately to the burden from non-specific work-related low back pain . They found that those people who had recurrences had longer duration of work disability than those who did not. Recurrent cases of low back pain have been shown to experience increased trunk stiffness, which may, in turn, increase the likelihood of further low back pain recurrence . Previous episodes of low back pain have been shown to be predictive of recurrence within a 12-month period .

Rates of recurrence are heavily reliant on how recurrence is defined , which also depends on how remission is defined. Hestbaek et al. studied the long-term course of low back pain and found that approximately 50% of people have a recurrent episode by 1 year, 60% by 2 years and 70% by 5 years . Stanton et al. found that within a 12-month period, recurrence of low back pain ranged from 24% to 33% . In a study of injured workers with low back pain, Côté et al. found that almost a third of workers experienced recurrence of back pain within 1 year . Another study found that 80% of primary care patients had experienced a recurrent episode of low back pain at 12 months . Cassidy found 20% of cases recurred within 6 months, and the rate of recurrence increased with age . Another study found that recurrent low back pain is common among school children aged between 10 and 16 years . Chenot et al. found that women were more likely than men to have recurrent low back pain .

Prevalence

Comparing the prevalence of low back pain between populations and over time is challenging due to considerable methodological heterogeneity across studies and difficulties in obtaining true population estimates. Having said this, there is considerably more literature on the prevalence of low back pain compared with incidence, remission and duration. Much of the methodological variation relates to the case definition and recall period, the age and sex distributions, the representativeness of the sample, the overall sample size, validation of the instrument used to measure prevalence, whether random methods were used in selecting the sample population, the extent of non-response and whether any measures were taken to deal with non-response bias. Systematic reviews have demonstrated particular case definition variation in relation to temporality and topography .

Definition by temporality

There are several ways that low back pain is defined by temporality – two common approaches are by recall period and episode duration. Definition by recall period is commonly used in cross-sectional studies. For example, a population-based study may define low back pain as ‘current’ low back pain (e.g., at the time of the interview) or ‘past’ low back pain (e.g., in the last 12 months) . As the length of the recall period increases, so too does the risk for recall bias.

In our systematic review of the prevalence of low back pain in the general population, the most common recall periods were 1 year and point. Estimates of the point prevalence of low back pain ranged from 1.0% to 58.1% (mean: 18.1%; median: 15.0%), and 1 year prevalence from 0.8% to 82.5% (mean: 38.1%; median: 37.4%). The distribution of estimates for common recall periods is shown in Fig. 1 . Table 3 presents the unadjusted prevalence from the studies considered to have a low risk of bias. Due to the heterogeneity of the data, mean estimates need to be interpreted with caution.

Mean and median prevalence in low back and back pain prevalence studies.

Table 3

The unadjusted prevalence of low back pain in the general population, by country.

Citation	Country	Age range (years)	Prevalence (%)	Standard error (%)	Risk of bias
Point prevalence
Walker et al.	Australia	18–99	25.6	1.00	Low
Skovron et al.	Belgium	15–99	33.0	0.76	Low
Cassidy et al.	Canada	20–69	28.7	1.35	Low
Hoy et al.	China	15–99	34.1	3.00	Low
Biering-Sorensen	Denmark	30–60	13.7	0.87	Low
Bredkjaer	Denmark	16–99	12.0	0.47	Low
Kohlmann et al.	Germany	25–74	39.2	3.41	Low
Mahajan et al.	India	15–99	8.4	0.87	Low
Mohseni-Bandpei et al.	Iran	11–14	15.0	0.51	Low
Carmona et al.	Spain	20–99	14.8	0.83	Low
Andersson et al.	Sweden	25–74	23.2	1.05	Low
Harkness et al.	United Kingdom	18–64	18.0	0.88	Low
Hillman et al.	United Kingdom	25–64	19.0	0.69	Low
One-week prevalence
Grimmer et al.	Australia	13–13	7.8	1.29	Low
Haq et al.	Bangladesh	15–99	20.1	1.11	Low
Davatchi et al.	Iran	15–99	14.8	0.50	Low
Al-Awadhi et al.	Kuwait	15–99	9.5	0.34	Low
Cardiel et al.	Mexico	18–99	6.3	0.49	Low
Chaiamnuay et al. )	Thailand	15–99	11.7	0.92	Low
Jones et al.	United Kingdom	10–16	15.6	1.62	Low
Minh Hoa et al.	Viet Nam	16–99	11.2	0.68	Low
One-month prevalence
Heistaro et al.	Finland	30–59	49.5	0.66	Low
Stranjalis et al.	Greece	15–99	31.7	1.47	Low
Kristjansdottir	Iceland	11–16	34.0	1.03	Low
Croft et al.	United Kingdom	18–75	39.0	0.73	Low
Watson et al.	United Kingdom	11–14	24.0	1.15	Low
Three-month prevalence
Miro et al.	Spain	65–99	43.9	2.04	Low
One-year prevalence
Lau et al.	China, Hong Kong	18–99	21.7	2.30	Low
Hestbaek et al.	Denmark	30–50	56.0	1.37	Low
Hestbaek et al.	Denmark	12–22	32.4	0.48	Low
Taimela et al.	Finland	7–16	9.7	1.23	Low
Demyttenaere et al.	Spain	18–99	20.0	1.23	Low
Demyttenaere et al.	Ukraine	18–99	50.3	1.70	Low
Walsh et al.; Demyttenaere et al.	United Kingdom	20–59	36.1	0.93	Low

Only gold members can continue reading. Log In or Register to continue

Share this:

• Click to share on Twitter (Opens in new window)
• Click to share on Facebook (Opens in new window)

Related

Related posts:

The global burden of musculoskeletal conditions – Why is it important? How to measure the impact of musculoskeletal conditions Rheumatoid arthritis Osteoporosis and fragility fractures Generalised musculoskeletal pain syndromes Epidemiology of gout: An update

Stay updated, free articles. Join our Telegram channel

Join