Survey of chronic pain in Europe: Prevalence, impact on daily life, and treatment

2.1.1 Screening questionnaire

The initial questionnaire was a screening interview that lasted approximately 5 min and consisted of 12 questions to assess the prevalence of chronic pain within each country, age and gender of respondents, the duration of pain, frequency of pain during last week, intensity of pain during last episode of pain, location of the pain, and the cause of the pain.

2.1.2 Structured in-depth-interview questionnaire

The respondents were considered to suffer from long lasting pain if they (a) had suffered from pain for at least six months, (b) had experienced pain in the last month, (c) experienced pain at least two times per week, and (d) rated their pain intensity when they last experienced pain as at least 5 on a 10-point Numeric Rating Scale (NRS) with 1 = no pain at all and 10 = the worst pain imaginable.

Respondents who fulfilled these screening criteria of the initial screening questionnaire were then interviewed in-depth using the second questionnaire of 44 questions. This in-depth interview lasted approximately 23 min. The respondents to the in-depth questionnaire were offered a small amount of money in appreciation for their time.

Questions in the in-depth interview assessed: (a) demographics, (b)frequency, duration and intensity of pain (c) the impact of pain on respondents' work and quality of life, (d) attitudes of respondents to their pain and its treatment, (e) respondents' perceptions of the attitudes of their family, friends, colleagues and doctors to their pain and its treatment, (f) respondents' interaction with healthcare professionals, including how many doctors respondents had seen, how often they had seen them and how long they had been seeing them, (g) treatments, including prescription and non-prescription medicines and non-medication strategies.

2.1.3 Translation of questionnaires into 16 European languages

Translators with four to 30 years' experience in medical or pharmaceutical translation translated the English language versions for other countries. All the regional language questionnaires were back-translated into English to confirm their accuracy.

2.2.1 Standard CATI methodology was used to perform the survey

Interviewers used listed residential telephone numbers to contact respondents in Austria, Belgium, Denmark, Finland, France, Germany, Ireland, Israel, Italy, the Netherlands, Norway, Poland, Spain, Sweden, Switzerland and the UK. The interviewers stratified the telephone numbers by region within a country to control regional bias, but drew numbers randomly within the regions and used CATI. Interviewers mainly contacted respondents on Monday to Thursday between 4 p.m. and 10 p.m. or on Sunday between 10 a.m. and 6 p.m. to allow potential access to the widest variety of householders.

Once the interviewers had spoken to at least 300 respondents fulfilling the criteria for in-depth questionnaire-based interviews, they stopped carrying out in-depth interviews in that country.

2.2.2 Sample survey methodological considerations

This survey was conducted according to the methods of broad-scale market research and we recognize the well-established biases created in any telephone interview. The prevalence rate could have been affected by limitations in capturing all pain populations. For example, cognitively impaired and nursing home residents could not be included. Only those people listed in telephone directories were included. Women are both more likely to answer the telephone and more willing to co-operate and take part in a survey than men, and there is also a greater likelihood that an older person is at home and is a land-line telephone user than a younger person.

To overcome some of these disparities, sample data were weighted by appropriate determinants of importance. Our goal was to create representative samples from countries that are widely disparate in size and obtain enough sample to determine differences between certain groups (e.g., age and gender) in a stable model that did not change in a substantial way as additional sample was collected.

The weighting procedures within each country used a cell-based weighting scheme with two gender categories (male and female) and seven age categories (18-30, 31–40, 41–50, 51–60, 61–70, 71–80 and 81+ years), creating 14 cells. These were balanced to the population figures obtained from the US Census Bureau International Database, summary of demographic information, October 2002 estimates. A balancing procedure was also adopted to adjust the sample cell proportions to the population cell proportions.

Two sets of weights were created. The first set was country-specific and created as already described. The second set adjusted those weights according to the relative size of the population and was used for the total pan-European results. All the pan European data quoted in this paper are based on the weighted population.

Respondents with chronic pain who were currently involved in clinical trials were excluded to ensure that the data reflected respondents who were receiving standard treatment for their pain.

2.2.3 Sample size

NFO determined the sample size for this survey based upon the following two-step approach (Cohen, 1988):

3.2.1 Demographics

Fifty-six percent of respondents suffering from pain who were interviewed in-depth were female, which is higher than the population estimate of 52% women. Those below 40 years of age appeared to suffer less, whereas the 41–60 age group appeared to be more likely than others to suffer from chronic pain (Fig. 2a). This telephone survey did not attempt to reach elderly persons in nursing homes etc, who often suffer from painful conditions. Pain was not more common in the oldest respondents in this survey than younger respondents. The mean (standard deviation) age of the respondents was 49.9 (17.4) years. The mean age and the percentage of females of the pain sufferers in the 16 countries are shown in 2b, 2c. The pain sufferers were younger in Israel, Poland and Italy, older in Germany, the Nordic countries, the Netherlands, France and Spain. There were more females among the pain sufferers in Ireland, France, Germany, Israel and the Netherlands (about 60%) than in the UK, Austria and Spain (about 50%) (Fig. 2c).

3.2.2 Duration of pain

The duration of pain was often prolonged (Fig. 3). Only 12% of the respondents suffered from chronic pain for less than two years, almost 60% had pain from two to 15 years and many respondents (21%) had suffered with pain for ≥20 years. Fig. 4 indicates that pain sufferers in Spain (9.1 years) and Finland (9.6 years) had the longest, in Ireland the shortest (4.9 years) duration of chronic pain at the time of the interview. Median for all 16 countries was 7.0 years.

3.2.3 Body locations of pain

Fig. 5a demonstrates the most commonly reported body locations and causes of pain. The causes given were in answer to the general question and aided by the interviewer reading a list of possible causes. Close to half of the patients had pain in the back, more than 40% had joint pain, most frequently knee-pain. One in 5 had head or neck pain, the same number had hand or leg pain.

3.2.4 Causes of pain (5a, 5b)

Osteoarthritis and rheumatoid arthritis combined was the most common cause of pain (42%). One in five reported chronic pain from deteriorated or herniated discs, degeneration or fractures of spine. Trauma or surgery caused chronic pain in 15%. Rheumatoid arthritis and migraine headaches occurred in less then 10%. Nerve damage or whiplash was given as causes in 4% each. A number of less frequently listed causes are not shown. Only 1% of respondents gave cancer as a cause of their pain. Twelve percent of respondents did not know the cause of their pain.

Osteoarthritis/arthritis and rheumatoid arthritis were given as causes for pain more often (35-48%) in the UK, Ireland, Italy, Spain, Norway and Belgium than in Finland and Israel (8-10%) and Austria, Germany, France (17-31%) (Fig. 5b). More traumatic (about 20%) and diabetic neuropathy (5%) were reported as causes in Israel. Herniated or deteriorating intervertebral discs were more common in Austria, Switzerland, Belgium (25%) than in Norway, Sweden, Finland and Denmark (6-14%) (Fig. 5b). Headaches and migraine appear to be more common in France, Germany, Poland, Belgium, Austria and Switzerland than in other countries.

3.2.5 Intensity of pain, tolerance to pain, and time course of pain

Sixty-six percent were suffering moderate pain when they last experienced pain (i.e. reported a pain score of 5–7 on a 1–10-point NRS scale (Breivik et al., 2000)) and 34% were suffering severe pain (i.e., reported a pain score of 8–10 on a 1–10-point NRS scale (Breivik et al., 2000)) (Fig. 6a). Prevalence of severe pain was lower in the Netherlands (18%), Norway and Sweden (24%), and Austria (26%). Prevalence of severe pain was clearly higher in Israel (50%), in Italy and Spain (43-44%), and Denmark, Belgium and Finland (35-37%) (Fig. 6b). Thus in Norway where the overall prevalence of pain was 30%, less than one in four pain sufferers experienced severe pain, whereas in Spain with the lowest overall prevalence of pain, almost half of the pain sufferers had severe pain. In Israel, the overall prevalence of chronic pain was 17%; 50% of the relatively young pain sufferers in Israel, 61% of whom were women, suffered from severe pain (Fig. 6b).

This pain rating is reflected in the results regarding respondents' attitudes to the severity of their pain. In 31% of cases, the pain at its worst was so severe that they could not tolerate any more; 47% said that they could tolerate only a little more, and 18% said that they could tolerate somewhat more pain (Fig. 6a).

Forty-six percent had constant pain and 54% had intermittent pain.

3.2.6 Impact of pain on activities of daily life

To gauge the impact of chronic pain on respondents' lives, the interviewers read out a list of activities and asked respondents to rate their ability to do the activities on a 3-point scale, i.e., as just as able, less able, or no longer able to take part. Many respondents were less able or no longer able to take part in various activities (Fig. 7). It should be noted that 79% said that their pain increased during the day as a result of their activity. Fig. 7 illustrates clearly how chronic pain in a majority of the sufferers severely affects sleep, ability to exercise, walk, do household chores, attending social activities, and maintaining independent lifestyle. Even ability to have sexual relations and maintaining family relationships are reduced in a quarter to almost half of the pain sufferers. The same proportion is less able to or unable to drive a car (Fig. 7).

3.2.7 Impact of pain on employment status

When questioned about their current employment status, 31% of the respondents with pain were employed full time, 13% were employed part time, 34% were retired and 22% were unemployed (Fig. 8). One in four said that their pain had impacted on their employment status (Fig. 8).

The interviewers then asked those respondents who were working how many days in the last six months they had lost from work because of their pain. The mean time lost from work due to pain was 7.8 days in this period. Fifty-five percent had lost no days at all, 11% had lost one to three days, 12% had lost four to nine days, 9% had lost 10 to 15 days, and 13% had lost at least 16 days.

The country specific data show that more days are lost due to pain in Finland (almost 20 days), the least in France (only 5 days) during the last 6 months (Fig. 9). When asked whether their employment status or hours they worked had anything to do with their pain, 32% who were not retired said yes.

A total of 19% had lost their job because of their pain, 16% had changed job responsibilities and 13% had changed jobs entirely because of their pain (Fig. 10).

Differences between the 16 countries in the impact of chronic pain on employment status are shown in Tables 2a and 2b. In the Netherlands, Denmark, UK, Israel, Sweden, and Norway chronic pain sufferers more often (24-29%) lose their jobs (and probably most often go to sickness retirement) than in Germany, Poland, Belgium, Ireland and France (14-15%). In Italy, Sweden, Norway, and Ireland change of job responsibilities or change of job because of pain occurs more often than in other countries, such as Spain, Belgium, Germany, Austria, Denmark, and France (Tables 2a and 2b).

3.2.8 Impact of pain on emotional status

When asked whether they had ever been diagnosed with depression because of their pain, 21% of respondents said yes (Fig. 10). Spain had the highest rate of depression among chronic pain sufferers (29%), followed by Norway (28%), Sweden and UK (24%). The lowest rate was reported in Denmark (11%) and Poland (14%) (Tables 2a and 2b).

3.2.9 Visits to doctors

The interviewers asked respondents how many times in the last six months they had visited their current doctor about the illness or medical condition that caused their pain. Sixteen percent had not seen their doctor at all, 14% had seen their doctor once, 60% had seen their doctor two to nine times and 11% had seen their doctor at least 10 times.

Thirty-five percent of respondents had consulted one doctor and 54% had consulted two to six different doctors (Fig. 11). The reasons for seeing more than one doctor was most often that their primary physician had referred the patients to a specialist (Fig. 11).

3.2.10 Type of doctor or health carer currently treating their chronic pain

Respondents were asked to describe the types of doctors they were currently seeing specifically for their pain. Most (70%) were seeing their general practitioner (GP) and 27% were seeing an orthopaedic specialist. Only 2% were currently treated by a pain management specialist (Fig. 12). Most respondents (69%) had been seeing the doctor that was currently treating their pain for one to 15 years.

When asked specifically whether they had ever been to a “pain management specialist”, as many as 23% said yes. The differences between the 16 countries are large, from 8% in Norway to 40–43% in France, Israel and Italy; clearly what the respondents mean by a “pain management specialist” must vary from country to country (Fig. 13).

3.2.11 Assessment of pain by doctors

When asked how often their doctor determined how much pain they were experiencing, 61% said at every visit, but 12% said never.

The interviewers then asked respondents how the doctor determined how much pain they were experiencing. The most common methods were for respondents to tell the doctor (71%) or the doctor to examine the respondent (52%); only 9% of respondents said that their doctor used a pain scale. In Finland as many as 20% of doctors used pain scales, 15% in the UK, and 14% in France, whereas only 4% used pain scales in Italy, 5 % in Norway and Poland (Fig. 14).

3.2.12 Treatment

The interviewers asked respondents whether their pain was being treated in any way. A total of 69% said yes.

3.2.12.1 Currently not receiving any treatment

Those who were not currently receiving treatment were asked to give their reasons why not (Fig. 15). The most common reason given was that respondents could manage the pain on their own, pain was not bad enough, or the pain condition was better now. However, many patients disliked taking medication, had side effects from treatment, had experienced that nothing more can be done, or had decided to live with their pain.

3.2.12.2 Non-drug treatment

Sixty-nine percent of respondents had used non-drug methods, remedies or treatments for their pain. This varied from 91% in Finland to 56% in Spain. The most common being massage (30%), physical therapy (21%) and acupuncture (13%), whereas relaxation therapy and counselling was used infrequently (Fig. 16). Thirty-eight percent of respondents felt that they had been extremely or very helpful.

The differences between the 16 countries were large, e.g. acupuncture had been tried by 41% in Sweden, around 25% in Austria, Switzerland, Norway, Denmark and the Netherlands, but only 5% in Finland, 6–7% in Spain, Poland, and Italy (Fig. 17).

Physical therapy also varied from high of 55% in Sweden, 52% in the Netherlands and 47% in Norway, to as little as 2% in France and 6% in Spain (Fig. 18).

Massage, may be a form of physical therapy: Austrians, Germans, and Poles try massage more often (47%, 46%, and 41%) than the British (15%) and the Irish (14%) pain sufferers (Fig. 19).

3.2.12.4 Currently taking prescription medicine

It should be noted that 21% of the 4 839 respondents had never taken a prescription medication for their pain. Twenty-six percent (634) had taken, but stopped taking prescription medicine. When asked for their reasons, 19% of respondents said that they managed or lived with the pain, 15% said that the pain was not bad enough, and 14% thought that there were too many side effects and/or did not like the side effects. Only 2% worried about the medicine being addictive (Fig. 20).

Most of the respondents who had taken prescription medication (3774), had taken one or two different prescription medications (65%), but over 10% had taken four or more.

3.2.12.5 Types of prescription medication currently used for chronic pain

The most common prescription medicines that were currently being taken by respondents were NSAIDs (44%), weak opioid analgesics (23%) and paracetamol (18%). Five percent were taking a strong opioid analgesic (Fig. 21).

When the data are broken down by country (Fig. 22; Tables 3a and 3b), it is clear that use of strong opioids varied widely from 0% in certain South-European countries to 12–13% in the UK and Ireland. Weak opioids varied even more: from 50% in UK and Norway, 36% in Sweden, 28% in Poland, between 18% and 22% in Switzerland, Ireland, France, Germany, and Finland to between 5% and 13% in Israel, Denmark, Italy, and Spain.

Table 3a. Currently used prescription pain medicines

	% Respondents
	UK (n = 146)	France (n = 146)	Germany (n = 124)	Italy (n = 90)	Spain (n = 164)	Poland (n = 106)	Sweden (n = 119)	Norway (n = 159)	Denmark (n = 142)
NSAIDs	23	25	54	68	49	71	27	24	38
			UIFWYDN	UIFGSYWDNBZEL	IUFWYDN	UIFGSWYDLNBEZA			UFY
	Weak opioids	50	19	20	9	13	28	36	50	8
IFGTSPWDLNBAZE		TDE	TDE		E	TSDNBAE	IFGTSCNBEAZL	IFGTSPWDLNBAZE
Paracetamol		38	38	2	6	8	8	26	45	0
	IGTSPWLNDAZ	IGTSPWLNDAZ	LNE	D	GD	GD	IGTSPDNAEZ	IGTSPWDLBAZEN
COX-2 inhibitors	3	6	8	7	2	1	7	11	8
		SP	USP	SP			SP	USP	USP
Strong opioids	12	4	4	0	1	4	3	6	11
	FGTSPWLZ							TS	FGTSPWLZ

• Answers to the structured interview question: “Which prescription pain medicines are you currently taking for the specific pain we have been discussing?”
• Statistical testing at the 95% confidence level: U, greater than UK; F, greater than France; G, greater than Germany; T, greater than Italy; S, greater than Spain; P, greater than Poland; W, greater than Sweden; Y, greater than Norway; D, greater than Denmark; L, greater than Finland; N, greater than Netherlands; B, greater than Belgium; A, greater than Austria; Z, greater than Switzerland and E, greater than Israel.

Table 3b. Currently used prescription pain medicines

	% Respondents
	Netherlands (n = 99)	Belgium (n = 148)	Finland (n = 177)	Ireland (n = 129)	Switzerland (n = 120)	Austria (n = 119)	Israel (n = 135)
NSAIDs	36	42	54	32	48	58	53
	UY	UFWY	UFY		UIFWY	UIFWYDNB	UIFWYDN
Weak opioids	14	15	22	19	18	14	5
	E	E	TSDE	TDE	DE	E
Paracetamol	11	33	26	5	12	4	3
	GDE	IGTSPDNAZE	IGTSPDNAZE	D	GDAE	E
COX-2 inhibitors	16	13	16	8	13	4	36
	UFSPWA	UFSPA	UFTSPWDA	USP	UFSPA		UIFGTSPWYDLNBAZ
Strong opioids	5	7	2	13	2	5	5
	TS	TSLZ		FGTSPWYNLAZE		TS	TS

• Answers to the structured interview question: “Which prescription pain medicines are you currently taking for the specific pain we have been discussing?”
• Statistical testing at the 95% confidence level: U, greater than UK; F, greater than France; G, greater than Germany; T, greater than Italy; S, greater than Spain; P, greater than Poland; W, greater than Sweden; Y, greater than Norway; D, greater than Denmark; L, greater than Finland; N, greater than Netherlands; B, greater than Belgium; A, greater than Austria; Z, greater than Switzerland and E, greater than Israel.

The percentage of respondents taking COX-2 inhibitors ranged from 1% to 16%, except in Israel, where they were taken by 36% of respondents (during spring-summer of 2003).

Adjuvants, such as anti-epileptics and tricyclic anti-depressants were not commonly used, with <5% of respondents saying that they were currently receiving these drugs (Fig. 21).

3.2.12.6 Effectiveness of prescription medication currently used for chronic pain

Regarding the effectiveness of their current prescription pain medicines, 45% of respondents felt that they were completely or very effective, 41% felt they were somewhat effective, and 15% felt they were not very or not at all effective. Moreover, 64% of respondents said there were times when their pain medicines were not adequate to control their pain, apparently when activity causes breakthrough pain (Fig. 23a).

The country-specific data on inadequate pain control from medication are shown in Fig. 23b: Sweden had the lowest percentage of inadequate pain control by medication (30%), whereas 71–79% reported that pain medication at times were inadequate in Ireland, Israel, Denmark, Switzerland and the Netherlands.

3.2.13 Overall effectiveness of treatment for chronic pain

Sixty percent of respondents thought that their pain was being adequately controlled. Around one-third (31%) had achieved pain control within six months from the time when they first experienced pain, but almost as many respondents (28%) had been in pain for over five years before they received effective treatment.

A pan-European average of 40% of pain sufferers were not satisfied with the effect of the treatment they were receiving for their long lasting pain. The country-specific data for overall inadequate pain control are shown in Fig. 27: This ranged from 27–33% in Finland, Ireland, Germany, Austria, and Spain to 40–45% in Israel, Italy, Norway and Sweden, and to as high as 54–61% in Switzerland, the Netherlands, Denmark and Belgium.

3.2.14 Satisfaction with doctors

Twenty-six percent of respondents were extremely satisfied with the doctor who was currently treating their pain, 36% were very satisfied and 28% were somewhat satisfied. Thus, 38% were not satisfied or only somewhat satisfied with the doctor treating their pain.

3.2.15 Respondents' attitudes and beliefs about pain treatment

The interviewers read a list of statements to respondents to determine their attitudes and beliefs about pain treatment (Fig. 24). Nearly two-thirds of respondents said that they worried about the side effects of medicines, over half said that they would rather take medication for their illness than their pain, around 40% were afraid of becoming addicted to pain medicine, and around 40% said that they would spend all their money on pain treatment if they knew it would work.

3.2.16 Respondents' attitudes and beliefs about their pain

The interviewers read a list of statements to respondents to determine their attitudes and beliefs about their pain (Fig. 25). Three-quarters of respondents considered their pain to be just part of their medical condition, half felt tired all the time, and around 40% felt that their pain prevented them from concentrating, made them feel helpless and meant that they could not function normally. Over one-third of respondents said that they could not remember what it was like not to be in pain. As many as 16% some days feel that their pain is so bad that they wanted to die.

3.2.17 Respondents' perception of the attitudes of others to their pain

Around 40% of respondents said that they felt their doctor would rather treat their illness than their pain and around 30% felt that their doctor did not know how to control their pain. Around 30% also felt that no one believed how much pain they were experiencing. About one in four to one in five felt that colleagues, employers, family and doctors were unsympathetic to the respondents' pain, did not think the pain was a problem, and did not understand how the pain affects the sufferers (Fig. 26).