Evidence from the basic literature search (done for the whole project) was used to assess this element. Methods for reporting clinical effectiveness data and assessment of strength of evidence are as described in Domain Methodology.

Three SRs were included to assess the effect of AAA screening on the overall or ‘all-cause’ mortality outcomes (Takagi 2010; Lindholt & Norman 2008; Cosford 2007). While the SRs by Takagi et al. and Lindholt & Norman were assessed as being of medium quality, the SR by Cosford et al. was determined to be of high quality (Appendix EFF-2, Section 2). GRADE Summary of findings (SoF) tables for these series of outcomes are shown in Appendix EFF-2 Section 5.

Overall mortality in men (long-term)

The  Takagi et al. SR was the most recent SR assessing long-term (i.e. after 7 to 15 years) overall mortality in men (Takagi 2010). Four RCTs included in total 114,376 men aged 65 years or more randomised to an invitation to attend screening for AAA (n=57,181) or no invitation (control; n=57,195). Pooled analysis of the four odds ratios (ORs) showed a non-significant reduction in overall mortality in the screened group (see SoF table in Appendix EFF-2 Section 5). The fixed-effect OR was 0.98 with a 95% confidence interval (CI) of 0.95 to 1.00, P=0.06.

Overall mortality in men (medium term)

The Lindholt & Norman SR was the most recent SR assessing medium term (i.e. after 3½ to 5 years) overall mortality in men (Lindholt & Norman 2008). Four RCTs included in total 125,576 men aged between 64 and 83 years randomised to an invitation to attend screening for AAA (n=62,729) or no invitation (control; n=62,847). Pooled analysis of the four ORs showed a non-significant reduction in overall mortality in the screened group (see SoF table in Appendix EFF-2 Section 5). The random-effect OR was 0.94 with a 95% CI of 0.86 to 1.20, P=0.14.

Overall mortality in women

The Cosford et al. SR was the most recent SR assessing overall mortality in women (Cosford 2007). One RCT included in total 9,342 women aged between 65 and 80 years randomised to an invitation to attend screening for AAA (n=4,682) or no invitation (control; n=4,660). The ORs showed a non-significant increase in overall mortality in the screened group (see SoF table in Appendix EFF-2 Section 5). The random-effect OR was 1.06 with a 95% CI of 0.93 to 1.21, P=0.40.

Evidence from the literature basic search (done for the whole project) was used to assess this element. Methods for reporting clinical effectiveness data and assessment of strength of evidence are as described in the Domain Methodology.

Three SRs were included to assess the effect of AAA screening on AAA-related mortality outcomes (Takagi 2010; Lindholt & Norman 2008; Cosford 2007). While the SRs by Takagi et al. and Lindholt & Norman were assessed to be of medium quality, the SR by Cosford et al. was determined to be of high quality (Appendix EFF-2, Section 2). GRADE SoF tables for these series of outcomes are shown in Appendix EFF-2, Section 5.

AAA-related mortality in men (long-term)

The Takagi et al. SR was the most recent SR assessing long-term (i.e. after 7 to 15 years) AAA-related mortality in men (Takagi 2010). Three RCTs included in total 86,449 men aged 65 years or more randomised to an invitation to attend screening for AAA (n=43,211) or no invitation (control; n=43,238). Pooled analysis of the three ORs showed a significant reduction in AAA-related mortality in the screened group (see SoF table in Appendix EFF-2 Section 5). The random-effect OR was 0.55 with a 95% CI of 0.36 to 0.86, P=0.008.

AAA-related mortality in men (medium term)

The Lindholt & Norman SR was the most recent SR assessing medium term (i.e. after 3½ to 5 years) AAA-related mortality in men (Lindholt & Norman 2008). Four RCTs included in total 125,576 men aged between 64 and 83 years randomised to an invitation to attend screening for AAA (n=62,729) or no invitation (control; n=62,847). Pooled analysis of the four ORs showed a significant reduction in AAA-related mortality (see SoF table in Appendix EFF-2 Section 5). The fixed-effect OR was 0.56 with a 95% CI of 0.44 to 0.72, P<0.00001.

AAA-related mortality in women

The Cosford et al. SR was the most recent systematic review assessing AAA-related mortality in women (Cosford 2007). One RCT included in total 9,342 women aged between 65 and 80 years randomised to an invitation to attend screening for AAA (n=4,682) or no invitation (control; n=4,660). The OR shows a non-significant increase in AAA-related mortality in the screened group (see SoF table in Appendix EFF-2 Section 5). The random-effect OR is 1.99 with a 95% CI of 0.36 to 10.88, P=0.43.

This research question was not assessed in any of the included literature.

NA

This research question was not assessed in any of the included literature in this domain, but since it is covered in the Safety domain in result card SAF1, SAF1 is referred to for EFF3.

NA

This research question was not assessed in any of the included literature.

NA

Evidence issued from the basic literature search (done for the whole project) is used to assess this element. Methods for reporting clinical effectiveness data and assessment of strength of evidence are as described in Domain Methodology.

One SR was included to assess the effect of AAA screening on the incidence of ruptured AAA (Cosford 2007). This SR was determined to be of high quality (Appendix EFF-2, Section 2). GRADE Summaries of findings (SoF) tables for this outcome for men and women are shown in Appendix EFF-2 Section 5.

Incidence of ruptured AAA in men

The Cosford et al. SR was the most recent SR assessing the incidence of ruptured AAA in men (Cosford 2007). One RCT included a total of 6,433 men aged between 65 and 80 years randomised to an invitation to attend screening for AAA (n=3,205) or no invitation (control; n=3,228). The ORs showed a significant reduction in the incidence of ruptured AAA in the screened group (see SoF table in Appendix EFF-2 Section 5). The random-effect OR was 0.45 with a 95% CI of 0.21 to 0.99, P=0.048.

Incidence of ruptured AAA in women

The Cosford et al. SR was the most recent SR assessing incidence of ruptured AAA in women (Cosford 2007). One RCT included in total 9,342 women aged between 65 and 80 years randomised to an invitation to attend screening for AAA (n=4,682) or no invitation (control; n=4,660). The odds ratio (ORs) showed a non-significant increase in the incidence of ruptured AAA in the screened group (see SoF table in Appendix EFF-2 Section 5). The random-effect OR was 1.49 with a 95% CI of 0.25 to 8.94, P=0.66.

This research question was not assessed in any of the included literature.

NA

Morbidity was assessed by Cosford et al., but the SR did not find any RCTs for outcomes that, for instance, were associated with complications of surgery such as distal embolus, haemorrhage and graft failure, coronary and cerebrovascular events or renal complications (Cosford 2007). However, as this research question is also covered in the Safety domain in SAF1, this is referred to for EFF7.

NA

This research question was not assessed in any of the included literature in this domain, but as it also is covered in the Description and Technical Characteristics (TEC) domain, relevant result cards within TEC are referred to for EFF16.

NA

This research question was not assessed in any of the included literature.

NA

This research question was not assessed in any of the included literature in this domain, but since it also is covered in the Health Problem and Current Use of the Technology domain (CUR), relevant result cards within the CUR domain are referred to for EFF20.

NA

This research question was not assessed in any of the included literature.

NA

Evidence issued from the basic literature search (done for the whole project) is used to assess this element. Methods for reporting clinical effectiveness data and assessment of strength of evidence are as described in Domain Methodology.

One SR was included to assess the effect of AAA screening on planned and emergency operations (Lindholt & Norman 2008). The SR was determined to be of medium quality (Appendix EFF-2, Section 2). GRADE SoF tables for these outcomes are shown in Appendix EFF-2 Section 5.

As this research question also is covered in the Organisational Aspects domain (ORG), result card ORG19 is therefore referred to for EFF19.

Planned operations in men (long-term)

The SR by Lindholt & Norman was the most recent SR assessing long-term (i.e. after 7 to 15 years) planned operations in men (Lindholt & Norman 2008). Three RCTs included in total 86,479 men aged between 64 and 83 years randomised to an invitation to attend screening for AAA (n=43,167) or no invitation (control; n=43,312). Pooled analysis of the three ORs showed a significant increase in planned operations (long-term) in the screened group (see SoF table in Appendix EFF-2 Section 5). The fixed-effect OR was 2.81 with 95% CI from 2.40 to 3.30, P<0.00001.

Planned operations in men (medium term)

The SR by Lindholt & Norman was the most recent SR assessing medium term (i.e. after 3½ to 5 years) planned operations in men (Lindholt & Norman 2008). Four RCTs included a total of 125,576 men aged between 64 and 83 years randomised to an invitation to attend screening for AAA (n=62,729) or no invitation (control; n=62,847). Pooled analysis of the four ORs showed a significant increase in planned operations (medium term) in the screened group (see SoF table in Appendix EFF-2 Section 5). The random-effect OR was 3.27 with 95% CI from 2.14 to 5.00, P<0.00001.

Emergency operations in men (long-term)

The SR by Lindholt & Norman was the most recent SR assessing long-term (i.e. after 7 to 15 years) emergency operations in men (Lindholt & Norman 2008). Three RCTs included a total of 86,479 men aged between 64 and 83 years randomised to an invitation to attend screening for AAA (n=43,167) or no invitation (control; n=43,312). Pooled analysis of the three ORs showed a significant reduction in emergency operations in the screened group (see SoF table in Appendix EFF-2 Section 5). The random-effect OR was 0.48 with 95% CI from 0.28 to 0.83, P=0.009.

Emergency operations in men (medium term)

The SR by Lindholt & Norman was the most recent SR assessing medium term (i.e. after 3½ to 5 years) emergency operations in men (Lindholt & Norman 2008). Four RCTs included a total of 125,576 men aged between 64 and 83 years randomised to an invitation to attend screening for AAA (n=62,729) or no invitation (control; n=62,847). Pooled analysis of the four ORs showed a significant reduction in emergency operations in the screened group (see SoF table in Appendix EFF-2 Section 5). The fixed-effect OR was 0.55 with 95% CI from 0.39 to 0.76, P=0.0003.

This research question was not assessed in any of the included literature.

NA

Return to work is assessed by Cosford et al., but the SR did not find any RCTs for this outcome (Cosford 2007). However, as this research question is also covered in the Social Aspects domain in result card SOC3, this is referred to for EFF11.

NA

This research question was not assessed in any of the included literature in this domain, but since it also is covered in the Social Aspects domain in result card SOC3, this is referred to for EFF12.

NA

This research question was not assessed in any of the included literature in this domain, but since it also is covered in the Social Aspects domain in result card SOC3, this is referred to for EFF13.

NA

Evidence issued from the basic literature search (done for the whole project) was used to assess this element. Methods for reporting clinical effectiveness data and assessment of strength of evidence are as described in Domain Methodology.

One SR was included to assess the effect of AAA screening on QoL in terms of state anxiety, depression and mental QoL (Collins 2011). This SR was determined to be of high quality (Appendix EFF-2, section 2). GRADE Summaries of findings (SoF) tables for these outcomes are shown in Appendix EFF-2 Section 5. No information on gender or age distribution was provided. Outcomes assessed were anxiety, depression and mental QoL. Anxiety was measured using STAI, the state scale of the state-trait anxiety inventory (Spielberger 1970), depression was measured using HADS, the state Hospital Anxiety and Depression Scale (Zigmond & Snait 1983), whereas mental QoL was measured using Short Form Health Survey SF-36 (Ware & Sherbourne 1992).

As this research question also is covered in the Social Aspects domain, result cards SOC1, SOC2, SOC3 and SOC4 are referred to for EFF9.

Anxiety

In the SR by Collins et al., in the one RCT that assessed anxiety, a total of 1,956 participants were randomised to an invitation to attend screening for AAA (n=1,230) or no invitation (control; n=726). Anxiety was significantly reduced in the screened group: the standard mean difference (Std.MD) was -0.12 with a 95% CI of -0.21 to -0.02 ((see SoF table in Appendix EFF-2 Section 5) P not indicated).

Depression

In the Collins et al. SR, depression was assessed in the same RCT, which included a total of 1,956 participants randomised to an invitation to attend screening for AAA (n=1,230) or no invitation (control; n=726). Depression was significantly reduced in the screened group:  the Std.MD was -0.11 with 95% CI from -0.20 to -0.02 (P was not indicated; see SoF table in Appendix EFF-2 Section 5).

Mental Quality of Life (QoL)

Mental QoL was also assessed in the RCT included in the Collins et al. SR in which a total of 1,956 participants were randomised to an invitation to attend screening for AAA (n=1,230) or no invitation (control; n=726). Mental QoL score was better in the screened group but not significantly so: Std.MD was 0.07 with 95% CI from -0.02 to 0.16 (P was not indicated; see SoF table in Appendix EFF-2 Section 5).

This research question was not assessed in any of the included literature in this domain, but since it also is covered in the Social Aspects domain (SOC), result cards SOC1, SOC2, SOC3 and SOC4 are referred to for EFF10.

NA

This research question was not assessed in any of the included literature in this domain, but since it also is covered in the Social Aspects domain (SOC), result cards SOC1, SOC2, SOC3 and SOC4 are referred to for EFF25.

NA

This research question was not assessed in any of the included literature in this domain, but since it also is covered in the Economic and Ethical Aspects domains (ECO and ETH), result cards ECO4, ETH1 and ETH7 are referred to for EFF14.

NA

The SR by Cosford et al. was the only SR to report patients’ acceptance of AAA screening programmes (Cosford 2007). This SR was determined to be of high quality (Appendix EFF-2, Section 2). However, this was not a pre-defined outcome, and the authors report acceptance rates from the RCTs included in the SR in narrative form only.

Cosford et al. reported acceptance rates ranging between 63% (Norman 2004) and 80% (Ashton 2002). In one trial the acceptance rate increased from 63% to 70% when, after randomisation, patients who were identified as too unwell or previously scanned were excluded (Norman 2004).

According to the SR, only one trial recorded acceptance rates by age (Scott 1995). In this trial men and women aged 65 accepted the invitation to screen most often (81% and 73% respectively), but acceptance decreased with age and was lowest for men and women aged 76 to 80 years (66% and 58% respectively).

As this research question also is covered in the Social Aspects domain (SOC), result card SOC5 is referred to for EFF15.

This research question was not assessed in any of the included literature in this domain, but as it also is covered in the Description and Technical Characteristics (TEC) domain, relevant result cards within TEC are referred to for EFF16.

NA

This research question was not assessed in any of the included literature.

NA

This research question was not assessed in any of the included literature.

NA

This research question was not assessed in any of the included literature.

NA

This research question was not assessed in any of the included literature.

NA

Evidence issued from the basic literature search (done for the whole project) is used to assess this element. Methods for reporting data are as described in Domain Methodology.

As no tools at the present are available for assessing the quality of reliability and agreement studies, no grading to indicate strength of evidence has been performed for these outcomes.

One SR was included to assess the variation of AAA screening interpretation in terms of variation in intra-observer repeatability and inter-observer reproducibility of infra-renal aortic diameter measurements using ultrasound (Beales 2011). This SR was determined to be of medium quality (Appendix EFF-2, Section 2).

Bland-Altman plots, a method based on the differences in observed values compared with the means of measured values was used to assess these outcomes in eight of the nine included studies (Bland & Altman 1986), whereas one study used a multilevel regression approach, i.e. generalised estimating equations (GEE) for the extraction of components of variation, separating intra-observer variation from inter-observer variation (GEE 2012). By using the GEE method, the number of assumptions for this analysis were reduced, which allowed variations to be reported in terms of standard deviations and appropriate definitions of measurement reliability derived from those standard deviations.

There were wide variations between the nine included studies in terms of numbers of measurements (from 10 to 112), participant demographics (age and gender) and types of ultrasound machine (all different). Various techniques of aortic diameter measurement techniques (calliper endpoints) were used, i.e. diameter measurement between aortic inner layers (ITI), between aortic inner and outer layers (ITO), or between aortic outer layers (OTO), and in both anteroposterior (AP) and transversal (TS) planes. Measurements were done on aneurysmal and normal aortas. In all studies, observers were blind to the results from the other observers, but they had different backgrounds in terms of discipline, grade or level of experience and training.

Intra-observer repeatability

The SR by Beales et al. was the only SR from the basic literature search that assessed intra-observer repeatability. Intra-observer repeatability was assessed using Bland-Altman plots by calculating repeatability coefficients in seven studies and using the GEE method in one study (Bland & Altman 1986; GEE 2012). Data for this outcome were not available for one of the nine included studies.

The intra-observer maximum AP mean difference ranged from 0.03 to 4.8 mm, and for TS from 0.2 to 1.9 mm. Beales et al. indicated diameter intra-observer repeatability coefficients, ranging from 1.6 to 7.5 mm for AP (and from 2.8 to 15.4 mm for TS). The National Health Service Abdominal Aneurysm Screening Programme (NAAASP 2009) suggested that 5 mm is an acceptable level of observer variation between aortic diameter ultrasound measurements. Authors suggested that aortic measurements by the same practitioner may vary significantly, but did not provide any statistical support for this statement, and the diameters (ITI, ITO or OTO) measured varied between studies. In addition, numbers of observers were few in eight of the nine included studies. It was difficult to draw a definitive conclusion from the review, but it indicated overall acceptable intra-observer repeatability.

In the studies included by Beales et al. numbers of observers ranged from 1 to 4, except for one study which had 24 observers (Hartshorne 2011). However, Hartshorne et al. included exclusively assessments of static images of aortas of different sizes, whereas the other eight studies included real-time examinations in which the relevant images to enable aortic diameter measurement were acquired. This study was nevertheless highlighted by the SR authors as being the only one that had used the GEE method. In this study, the intra-observer AP mean repeatability coefficients varied from 1.6 to 2.0 mm with individual repeatability coefficients ranging from 0.8 to 6.1 mm (TS measurements were not performed in this study), which are mainly below the acceptable level of variability of 5 mm (NAAASP 2009).

Intra-observer variability for ITI and OTO aorta diameter measurements

Hartshorne et al. was the only study that assessed possible differences in intra-observer variability according to different calliper endpoints of aortic diameter measurements (i.e. diameter measurements of ITI walls versus OTO walls), as well as according to differences in observers’ background disciplines and experience (screening technicians versus vascular sonographers). In this study, 13 screening technicians and 11 vascular sonographers examined 60 aortic static images (not live). Among the sonographers, six had more than 10 years’ experience and only one had less than 1 year of experience, whereas only two screeners had more than 10 years’ experience and five had less than one year. While all 13 screeners routinely used ITI, five sonographers used OTO and six both ITI and OTO in their routine practice. When 15 images were each measured twice in random order by all 24 observers, there was no significant difference between the mean repeatability of ITI, 1.6 mm (range 0.8-5.2 mm) and that of OTO, 2.0 mm (range 0.5-6.1 mm). For ITI, there was no significant difference between the mean repeatability of screeners, 1.7 mm (range 0.8-5.2 mm) and that of sonographers 1.4 mm (range 0.9-2.4 mm; P=0.27). For OTO, on the other hand, the mean repeatability was significantly better for sonographers at 1.4 mm (range 0.6-2.6 mm) compared with screeners, mean 2.5 mm (range 1.1-6.1 mm; P=0.037).  It was, however, not possible to ascertain, using these data, the effect of the sonographers’ longer experience since screeners, as opposed to sonographers, did not use OTO in their routine practice.

Inter-observer reproducibility

The SR by Beales et al. is the only SR from the basic literature search that assessed inter-observer reproducibility. Inter-observer reproducibility was assessed using Bland-Altman plots in eight studies and by the GEE method in one study (Bland & Altman 1986; GEE 2012).

For AP, the limits of agreement (reproducibility coefficients) for the diameter measurements ranged between -1.9 to +1.9 mm and -10.4 to +10.5 mm (all nine studies), whereas for TS, the largest limit of agreement was -5.6 to +5.2 mm (only two studies assessed TS diameters). According to Beales et al., five of the nine studies included had acceptable inter-observer reproducibility. For the study that involved 24 observers and used the GEE method (Hartshorne 2011), as opposed to the 1-4 observers in the eight others, the mean reproducibility coefficients were 3 mm (95% CI 2.4-3.6 mm) for ITI and 4.2 mm (95% CI 3.5-4.9 mm), both of which were below the acceptable level of variability of 5 mm (NAAASP 2009). Although the authors of the SR do not draw any conclusions about inter-observer reproducibility, the results indicate overall acceptable inter-observer reproducibility regardless of whether diameters are measured as ITI, OTI or OTO.

Inter-observer variability for ITI and OTO aorta diameter measurements

Hartshorne et al. was the only study that assessed possible differences in inter-observer variability according to different calliper endpoints of aortic diameter measurements (i.e. diameter measurements of inner-to-inner walls [ITI] versus outer-to-outer walls [OTO]), as well as according to differences in observers’ background disciplines and experience (screening technicians versus vascular sonographers) (Hartshorne 2011). In this study, in which 13 screening technicians and 11 vascular sonographers examined 60 images, mean reproducibility coefficient for ITI was significantly better than for OTO when measuring AP (TS was not measured in this study). Mean reproducibility coefficient was 3.0 mm (95% CI 2.4-3.6 mm) for ITI and 4.2 mm (95% CI 3.5-4.9) for OTO (P<0.05), but both remained acceptable according to NAAASP, i.e. less than 5 mm (NAAASP 2009). Hartshorne and collaborators performed a corresponding analysis, excluding observers with less than 1 year’s experience. In this group of 8 screening technicians and 10 sonographers mean reproducibility coefficients were 3.2 mm (95% CI 2.6-3.8 mm) for ITI and 3.8 mm (95% CI 3.1-4.5 mm) for OTO. It was not possible, however, to ascertain that there was no effect of background discipline, because the screening technicians, as opposed to sonographers, did not use OTO in their routine practice.

Impact of ITI and OTO on the threshold for surveillance and referral for treatment

Hartshorne et al. grouped the 60 images into four categories to assess the impact of ITI versus OTO on the threshold for surveillance and referral for treatment. Results presented in the table below (Table 1- EFF33) indicated that the ITI method would detect fewer aneurysms than using OTO.

Table 1 – EFF33 : Size categories using ITI vs size categories using OTO using 1440 measurements

<30 mm is considered normal and requires no further surveillance (adapted from Hartshorne et al. 2011)

30-45 mm is considered a small aneurysm requiring yearly assessments

45-55 mm is considered a medium large aneurysm requiring 3-monthly assessments

>55 mm is considered a medium large aneurysm requiring immediate surgery

However, as indicated earlier, this study did not assess live images, and half of the observers were screening technicians who had less experience than vascular sonographers, and who used only ITI in their practice routine. These factors meant that a definite conclusion could not be drawn based on these data about the thresholds for surveillance and referral for treatment.

This research question was not assessed in any of the included literature in this domain, but since it also is covered in the Safety domain (SAF), result card SAF3 is referred to for EFF22.

NA

This research question was not assessed in any of the included literature in this domain, but since it also is covered in the Safety domain (SAF), result card SAF3 is referred to for EFF23.

NA

This research question was not assessed in any of the included literature in this domain, but since it also is covered in the Safety and the Economic domains, result card SAF1 and relevant cards within the ECO domain are referred to for EFF24.

NA