Independent report

Entitlement to benefit and medical assessment within the IIDB scheme: IIAC information note

Published 19 June 2018

Backgound

This information note provides in one convenient place a summary of several recent linked investigations by the Industrial Injuries Advisory Council (IIAC) into the rules and processes used to evaluate entitlement to benefit under the Industrial Injuries Disablement Benefit (IIDB) Scheme.

More detailed commentaries and a fuller account of the council’s recommendations have been published elsewhere. A bibliography of relevant publications is provided.

The legal context

1. Employed earners can claim IIDB if they incur an occupational injury or develop a prescribed disease (PD) in the terms defined in Schedule 1 of the Social Security (Industrial Injuries) (Prescribed Diseases) Regulations 1985.

2. Assessment of their claim involves a review of their employment history, circumstances of exposure or injury, and a medical assessment of the diagnosis and of the functional impact of related impairments (‘disablement’).

3. The 1985 Regulations set out criteria by which claims for IIDB in employed earners must be tested. These include whether the claimant has the disease defined in Schedule 1 (the ‘diagnosis’ question); whether he or she has had the occupational exposure in the schedule (the ‘occupational’ question); and whether the disease can be presumed to be “due to the nature of employment” and over what time frames relative to their work history (the ‘causation’ question). Alternatively, a claim can be tested against whether a personal injury has been sustained “out of and during the course of his employment” (Social Security Act, 1975, Section 50), in which case similar questions of diagnosis, entitlement and attribution to work have to be addressed.

4. The regulations also enable decision-makers to decide that a claimant’s disease was not caused by their work and to rebut (or refuse) the claim if “the contrary is proved”.

5. A step that follows on when other matters are accepted is that of assessing the extent of disablement caused by the relevant injury or PD (called the ‘disablement’ question).

6. To support consistency and equity of decision-making at this stage, the legislation includes a schedule of Statutory Scheduled Assessments, or table of injuries (Social Security (General Benefit) Regulations 1982, Schedule 2). This describes prescribed levels of disablement for certain pre-defined categories and degrees of traumatic physical injury as a guide to decision-makers.

7. Awards to qualifying claimants may sometimes be subject to deductions, however, reflecting the opinion that a part of their disablement is non-occupational in origin. The legal basis for this is set out in several statutes and regulations including Regulation 11 of the Social Security (General Benefit) Regulations 1982.

Council inquiries

8. The council has undertaken several linked investigations into the rules and processes used to determine entitlement to benefit. Specifically, separate strands of work have looked at: the ‘causation’ question and the coverage of presumption (paragraph 3); the use of rebuttal (paragraph 4); the process of making deductions under Regulation 11 (paragraph 7); and the table of injuries, as well as the injuries and diseases covered by the Scheme (paragraph 6).

9. To inform these reviews, at one stage a sample of decided case files was audited and at two other stages IIDB statistics were analysed to understand better the scale of awards attracted by different PDs. The Medical Assessments Working Group, a limited term subgroup of the council, met on several occasions to consider the evidence. An external review was also commissioned. This Information Note summarises these inquiries and the conclusions drawn from them.

Presumption

10. ‘Presumption’ is a cardinal feature of the scheme, important to its efficiency. It allows decision-makers evaluating individual claims to presume that a disease is work-caused. This has the two-fold policy intention of: sparing claimants the burden of gathering detailed evidence to demonstrate occupational causation, especially where this could be slow, costly, and difficult; and streamlining the scheme’s administration, allowing it to be run in a simple, consistent and straightforward manner with prudent and proportionate use of public funds. By avoiding an adversarial system of individual proofs, a much higher proportion of available funds are delivered to claimants and more speedily than would be possible in, often protracted, civil proceedings.

11. The governing regulation (Social Security (Industrial Injuries) (Prescribed Diseases) Regulations 1985, Regulation 4) and related prescription schedule set out the circumstances in which attribution to work is more likely than not, based on a detailed independent scientific evaluation of the causal probabilities.

12. Before the council’s review, Regulation 4 held broadly that a scheduled PD could be presumed to be due to the nature of claimant’s work if the schedule’s occupational criteria were met and the disease developed during that employment or within a month of leaving it. However, not all PDs attracted the benefit of presumption while some had time rules of eligibility that were specific only to them. More significantly, the rule was written in the mid-twentieth century at a time when most PDs developed swiftly during employment; but many ‘long latency’ diseases now covered by the scheme (e.g. mesothelioma, other cancers) develop decades after leaving the causative employment, thus rendering the time course of “onset in the job or within a month thereafter” inappropriate in relation to them.

13. The council therefore reviewed the coverage and time limits of presumption across all of the scheme’s PDs. Following the implementation of its recommendations, the interval over which presumption should apply was legally extended in the case of 27 of the Scheme’s 71 PDs, two PDs were accorded presumption partially for the first time, and for one it was partially withdrawn. This was a necessary modernisation of an important principle in the light of current medical and scientific knowledge.

Further information can be found in:

• Presumption that a disease is due to the nature of employment: coverage and time rules (Cm 8880, London, The Stationery Office, 2014)

Rebuttal

14. A nuance of Regulation 4 is that decision-makers are given the power to rebut (refuse) a claim if proof is said to exist that the disease was not caused by a claimant’s work (“the contrary is proved”). This provision allows flexibility to reject claims where it would clearly be wrong to pay benefit – for example, those involving trivial exposures. On the other hand, rebuttal risks sacrificing some of the gains in administrative efficiency that presumption offers.

15. Importantly, also, rebuttal can be challenging to apply correctly. This last concern arises particularly in respect of diseases which, when occupationally caused, are clinically indistinguishable from the same disease caused by factors outside work. Attribution to work in a claimant with both occupational and non-occupational risk factors rests then on an assessment of causal probabilities, rather than on clinical judgement, and may be liable to errors in causal reasoning.

16. The council reviewed the application of rebuttal in its main Command paper (Cm 9030) and highlighted the ease with which such errors can arise in a technical companion paper (position paper 34).

17. ‘A cause’ of a given outcome is a factor that makes that outcome more (or less) likely; but most events in life have several causes. It is counter-intuitive but often true that a disease can be caused both by a factor outside work and by work itself in the same individual at the same time. Usually causes do not compete with one another (X or Y caused this disease) but they act together (both X and Y were responsible). Hence, proof that a non-work factor may have contributed to a disease does not exclude it also being occupationally caused and does not constitute proof to the contrary.

18. Cm 9030 gave guidance on rebuttal for all of the 71 PDs and identified many PDs for which the prescription schedule, with rare exception, should simply and automatically apply. Very often, accepting the schedule as written will offer a fairer, more consistent and appropriate basis for deciding whether a disease is due to the nature of employment, with the added potential of being resource-sparing and simpler to enact.

Further information can be found in:

• Presumption that a disease is due to the nature of employment: the role of rebuttal in claims assessment (Cm 9030, London, The Stationery Office, 2015)

• Diseases with multiple known causes and rebuttal (position paper 34, London, Corporate Document Services, 2015)

‘Other effective causes’ of disablement

19. Awards to qualifying claimants are sometimes subject to deductions made under Regulation 11 of the Social Security (General Benefit) Regulations 1982.

20. The rule is complicated (e.g. it allows an increase for interactions that cause worsening), but in essence it permits disability from so-called ‘other effective cause(s)’ to be subtracted before setting the final level of award.

21. ‘Other effective cause’ refers to a congenital defect, pre-existing injury or disease that is non-occupational in origin. However, some commissioners have held nuanced and sometimes differing views about the place for non-occupational risk factors within this framework. This has led sometimes to deductions for previous injury in claimants who have made a full recovery and completed a long, physically demanding career before developing symptoms of an otherwise qualifying PD.

22. The council’s inquiries have found some evidence of inconsistent practice. Ambiguity about the underlying principles and legal constraints, and precedents of tribunals appear gradually to have shaped practice, leading to a different treatment for claimants of some PDs and differing treatment of some risk factors.

23. A need was identified to ensure specialists charged with making decisions receive clear, evidence-based guidance on the circumstances in which it would be scientifically justifiable to deduct from the level of disability compensation in claimants with several possible causes of disease or injury.

24. In Cm 9632 the council described the principles and science that should apply. It recommended that deductions should not be made under Regulation 11 for non-occupational risk factors of PDs and injuries. However, a deduction from disability compensation can reasonably be made where the evidence shows that pre-existing disability is present from a coincident non-occupational cause.

Further information can be found in:

• Diseases with multiple known causes, occupational injuries, and medical assessment (Cm 9632, London, The Stationery Office, 2018)

The ‘table of injuries’; international comparisons

25. As highlighted in paragraph 6, a schedule (‘table of injuries’) exists for certain pre-defined types and degrees of traumatic physical injury which provides a guide to decision-makers when setting the levels of awards. The Social Security (General Benefit) Regulations, Schedule 2 was drawn up years ago for the purposes of the War Pensions Scheme. Unchanged over many decades, it does not cover every type of injury for which a claim can be made, matches somewhat poorly the pattern of injuries presenting to the Scheme by present day claimants, and covers injuries but not diseases.

26. To assess disablement in non-scheduled impairments, trained medical assessors armed with suitable guidelines extrapolate from Schedule 2, making comparisons between the effects of tissue loss listed in the Schedule and the wide variety of impairments which are the subject of modern claims.

27. Many challenges exist. It is less than straightforward, for example, to rank a chest injury relative to an injury of a limb, or to compare the effects of disease to those of injury in deciding how, say, progressive breathlessness should be ranked relative to a given instance of physical injury.

28. A basic requirement of any schedule supporting award for loss of function is that it ranks claimants equitably and in priority, such that those with the greatest losses through injury or disease receive the greatest benefit. This in turn requires that the elements in a table of injury have a logically consistent hierarchy which guarantees equity, both vertically (ranking within different degrees or severity of the same condition) and horizontally (comparison between different conditions).

29. Mindful of these complex and difficult challenges, the council used its small annual research budget to commission a review involving an international comparison of state-supported schemes that award benefit or compensation for occupational injury and occupationally-related disease. Attention was restricted to schemes which, whatever their other qualifying conditions, adopted loss of function as the primary basis for award of benefit, as the IIDB Scheme does, and which also had written schedule(s) by level and type of injury/disease to define the ranking of disablements.

30. The reviewers were asked to map the relative ranking of injuries scheduled within the IIDB scheme and to draw systematic comparisons with tables of injury or disease in other jurisdictions. Such information might be used to test whether the IIDB scheme has a similar list and coverage to other comparable schemes; how much international agreement there is regarding the relative functional impact of different types of injury; and whether the IIDB scheme is broadly in step with other similar schemes in its relative ranking of injuries or whether any classes of injury appear to be ranked anomalously.

31. The reviewers compared data from seven jurisdictions (in Denmark, Australia, Italy, Canada, Switzerland, Finland and Luxembourg). Schemes differed in terms of their organisation, provisions for assessment, ways of assessing disablement and tables of scheduled injuries (including their relative rankings). However, they shared many principles in common.

32. The review’s findings indicated that the IIDB scheme is broadly in line with international comparators that have a similar aim. Such differences in relative ranking of injury as exist are minor, and on a scale at least as comparable to that seen more generally between schemes of other jurisdictions. One significant difference is that the table of injuries contains only 55 injury types as compared with 175 in Alberta, 474 in Denmark and 1,255 in New South Wales (which cover diseases as well as injuries). An area meriting further consideration is whether the scheme would benefit from a fuller schedule, as several other countries have.

Further information can be found in:

• Stilz R, Baker A – Assessing disablement under the Industrial Injuries Disablement Benefit Scheme a critical review and international comparison, Dec 2014

• IIAC commentary on the commissioned review: Assessing disablement under the IIAC Scheme a critical review and international comparison (Dec 2014)

Other inquiries

33. Within the general work stream, published quarterly statistics on IIDB (2009 to 2011) were summarised in terms of the proportion of first diagnosed assessments awarded different levels of disablement, overall and for the principal PDs (see appendix).

34. Over half of PDs were assessed at below 14%, the general cut-point for receiving benefit, while 9.9% were at, or close to, the maximum benefit. Bursitis, tenosynovitis, hand-arm vibration syndrome, rhinitis and dermatitis attracted low levels of disability assessment, whereas major cancers were invariably assessed in the top band for award purposes. For certain PDs (pneumoconiosis, occupational asthma, diffuse pleural thickening, chronic obstructive pulmonary disease) awards were over a wider range from a low to medium scale of award.

35. The appropriateness of individual awards cannot, of course, be assessed with certainty from these summary data. However, the general pattern has so-called ‘face validity’, that is to say that it looks reasonable on the face of it. The council was reassured that claimants of the most serious diseases were awarded the highest benefits, that award levels were lower relatively for less disabling and sometimes self-limiting diseases, and that a spectrum of awards was found for diseases whose functional effects would be expected a priori to exist across a spectrum.

36. A concern sometimes raised by stakeholders at public meetings is whether awards are systematically rounded down at the 14% threshold, thereby denying claimants benefit. Published statistics are subject to rounding, but an analysis of 96,500 newly accepted claims for PDs during 2002 to 2011, which could assess degree of disablement to the nearest percentage point, provided a greater level of granularity on this question. Each of 45 PDs involving three or more cases were considered. For all but two of the PDs^{[footnote 1]} evidence was found of a spike in the number of cases assessed at 14% disability and a relative deficit of awards at 13%. The most obvious explanation for this finding is that medical assessors tend to err on the side of generosity in assessing claims that fall close to a payment trigger point. Small awards of different kinds can be aggregated (added together). The dataset did not allow an exploration of aggregated awards on either side of the payment threshold, but it seems unlikely if individual PDs spike at 14% that aggregation would result in claimants being systematically disadvantaged.

37. Evidence was also found of clustering around multiples of 5%. This probably reflects medical judgements being formulated within broad and not fine divisions of precision, supporting guidance to medical assessors favouring a degree of rounding in the final assessment. In the council’s view this is both reasonable and pragmatic.

38. Also, within this work stream, in 2013 the council conducted a small audit of decided case files. The audit was used to inform other inquiries mentioned in this note. IIAC was reassured to find few problems in relation to the ‘causation’ question although some instances involved deductions of benefit for “other effective causes” that were risk factors. In general, the reasoning behind decisions was well documented, although poorly so in a few files. Other potential inconsistencies of a minor nature were referred to the department’s policy officials.

Concluding remarks

39. The process of assessing entitlement to IIDB is complex, both in terms of the rules that are applied, and the judgements medical assessors and decision makers have to make.

40. The inquiries summarised in this note have sought to make the underlying principles as clear as possible, to aid transparency and consistency, and to ensure that decision-making is scientifically robust. Where appropriate, the rules have been modernised. Elements of the framework have been benchmarked against international comparators and other elements inspected, to gauge their reasonableness to independent scrutiny.

41. Advice has been offered to the department and other stakeholders to streamline decision-making. The council has offered to work with the department’s medical policy advisors to ensure that guidance to medical assessors reflects its advice.

42. The council believes that simplification would make an already relatively efficient system more so, and that this would be to the benefit of claimants and administrators alike.

Appendix

Industrial Injury prescribed diseases, first diagnosed all assessments, by prescribed disease and percentage assessment: June 2009 to September 2011 (list restricted to PDs assessed in the period)

		1 to 13	14 to 19	20 to 24	25 to 34	35 to 44	45 to 54	55 to 64	65 to 74	75 to 84	85 to 94	95 to 100
All prescribed diseases (n=39,100)*		54.1%	19.0%	7.5%	5.7%	2.1%	0.8%	0.3%	0.2%	0.3%	0.1%	9.9%
A6	Bursitis of the knee	87.0%	13.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%
A8	Tenosynovitis	58.8%	41.2%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%
A10	Occupational deafness	0.0%	0.0%	44.8%	37.9%	17.2%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%
A11	Vibration white finger/HAVS	97.2%	2.8%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%
A12	Carpal tunnel syndrome	78.7%	20.0%	1.3%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%
A14	Osteoarthritis of the knee in miners	62.5%	22.7%	7.7%	5.1%	1.5%	0.4%	0.1%	0.0%	0.0%	0.0%	0.0%
D1	Pneumoconiosis	25.2%	19.2%	15.9%	17.8%	7.5%	4.7%	3.3%	1.9%	2.3%	0.0%	2.3%
D3	Diffuse mesothelioma	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	100.0%
D4	Allergic rhinitis	100.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%
D5	Dermatitis	100.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%
D7	Occupational asthma	21.7%	39.1%	21.7%	13.0%	4.3%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%
D8	Carcinoma of lung with asbestosis	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	100.0%
D8A	Lung cancer, exposure to asbestos	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	0.0%	100.0%
D9	Diffuse pleural thickening	14.8%	23.5%	19.8%	22.2%	11.1%	7.4%	1.2%	0.0%	0.0%	0.0%	0.0%
D12	Chronic bronchitis and/or emphysema	4.5%	0.0%	22.7%	31.8%	22.7%	13.6%	4.5%	0.0%	0.0%	0.0%	0.0%

*The data are subject to small errors arising from the summing of published numbers, which are rounded

References

1. The 2 PDs that did not show spikes at 14% disablement were occupational deafness (PD A10) – for which there are different arrangements for payment and where the definition of the disease is effectively linked to a minimum of 20% disablement; and anaphylaxis due to latex (PD B5) for which the total number of cases was small. ↩