Participation in paid and unpaid work one year after injury and the impact of subsequent injuries for Maori: Results from a longitudinal cohort study in New Zealand.

INTRODUCTION: Indigenous populations experience greater injury burdens than non-indigenous groups. This paper investigated, for injured Maori (New Zealand's indigenous population): 1) participation in paid and unpaid work 12 months after injury, 2) whether subsequent injuries are predictive of reduced participation, and 3) if particular characteristics of subsequent injuries predict reduced participation. METHODS: The Subsequent Injury Study utilised data from the earlier Prospective Outcomes of Injury Study, a study of 2856 injured New Zealanders (including 566 Maori; 20%) who had an Accident Compensation Corporation (ACC; New Zealand's no-fault injury insurer) entitlement claim (sentinel injury). Data about subsequent injuries reported to ACC and hospital discharge data for injuries resulting in hospitalisation were also utilised. Multivariable models were used to examine if certain aspects of subsequent injury predicted either of two outcomes - reduced participation in paid, and unpaid work 12 months after a sentinel injury. RESULTS: Eligible participants were identified from the 405 Maori participants interviewed at 12 months. Thirty-two percent sustained at least one ACC subsequent injury, and 16% reported reduced participation in unpaid work. Of the eligible participants working for pay at the time of their sentinel injury, 35% reported reduced participation in paid work. Although the relationship between sustaining a subsequent injury (or not) and reduced participation in paid work was unclear (aRR 1.4, 95%CI 0.9,2.3), particular subsequent injury characteristics were identified as being independently predictive: subsequent injury resulting from an assault (aRR 2.4, 95%CI 1.2,4.9), a subsequent injury involving an entitlement claim (aRR 2.0, 95%CI 1.1,3.4), sustaining more than one subsequent injury (aRR 2.0, 95%CI 1.1,3.6), and only non-work-related subsequent injuries (aRR 1.6, 95%CI 1.0,2.7). CONCLUSIONS: Reduced participation in paid work is prevalent for Maori after an ACC entitlement claim injury. Particular characteristics of subsequent injuries after such an event impacts on participation in paid work 12 months after the sentinel injury, but the picture is less clear for unpaid work. Understanding the changes in paid and unpaid work, and the predictive characteristics of subsequent injuries for injured Maori, is important for future injury prevention strategies and supporting return to work rehabilitation programmes, specifically for Maori.

Use of alcohol intoxication codes for serious non-fatal hospitalised injury.

AIM: To determine the extent to which ICD-10 alcohol intoxication codes are used for serious hospitalised injury and the distribution of these codes according to gender, age, injury mechanism and intent, severity of injury, and whether the patient was treated in an Intensive Care Unit. DESIGN: Cross-sectional study. SETTING: New Zealand. PARTICIPANTS: All injury hospital discharges in 2010 that met specified severity criteria. MEASUREMENTS: Cases which had a measurement of BAC (Y90) coded, or only a subjective assessment of alcohol intoxication (F10.0). FINDINGS: 2.5% had a blood alcohol recorded (Y90) and a further 3% were coded as being intoxicated but there was no blood alcohol code. All factors investigated were shown to be independently associated with the assignation of codes. Notable findings were the elevated odds of an alcohol code for males, assault and the more severe injuries. CONCLUSIONS: Assessment of alcohol intoxication among seriously injured persons appears to be very uncommon. The development of a standardised instrument for clinical judgement of intoxication would be highly desirable.

Age, cohort and period effects on hip fracture incidence: analysis and predictions from New Zealand data 1974-2007.

UNLABELLED: Hip fractures are substantial problem worldwide. The increase in rate with age does not continue into very old age. Rates decline in successive birth cohorts. If the increasing trend in period effect continues, there will be a substantial increase in hip fracture incidence. INTRODUCTION: The purpose of this study is to (1) determine incidence rates for fracture neck of femur (FNF) for the period 1974-2007, (2) estimate age, cohort, and period effects, and (3) predict the burden of FNF in 2025. METHODS: Age adjusted incidence rates were estimated using New Zealand hospital discharge data for 1974-2007. Age-period-cohort modeling was used to estimate individual effects of these factors after adjusting for the other two factors. Future fracture burden was estimated under two scenarios. RESULTS: Age-adjusted rates for women increased from 1974 to 1987 whereas rates for men have increased from 1974 until 2007. Risk increased from 70 years of age but dropped among the very elderly. Period effects showed a steady increase in risk throughout 1974-2007. In contrast, the risk was lower in later cohorts. If there is no change in the period effect from 2007 we estimate a reduction in the burden of illness from FNF, especially for women. However if the period effect continues to increase, there will be substantial increases in FNF incidence, especially for men. CONCLUSIONS: The effect of population aging on FNF incidence is predictable because projections are based on an existing population. The increasing health and improvement in measures of physical status of older people through the last century, explain the decline in FNF incidence in later cohorts. The steady increase in period effect may be due to increased survival of the very frail. This burden of illness resulting from FNFs must be addressed by population based, research proven approaches to fall and fracture prevention.

Is length of stay in hospital a stable proxy for injury severity?

RESEARCH QUESTION: Is length of stay (LoS) in hospital a stable proxy for severity of injury when monitoring time trends in serious injury incidence? OBJECTIVE: To investigate whether LoS metrics (mean, median and proportion exceeding several LoS thresholds) have changed over time for injury diagnoses with known severity. DESIGN: Time series investigation. SUBJECTS AND SETTING: New Zealand population admitted to hospital for injury and discharged during the period 1989 to 1998. MAIN OUTCOME MEASURES: Interpolated median and geometric mean lengths of stay, as well as the proportion of cases that have an LoS greater than or equal to 3, 4, 7 and 14 days in hospital. METHODS: ICD-9-CM diagnoses that are approximately homogeneous in regard to severity of injury (ICD-HS diagnoses) were identified. Trends were investigated in the LoS statistics for: injury and non-injury diagnoses combined; all injury diagnoses; major body sites of injury; severity strata; and ICD-HS diagnoses. RESULTS: Almost without exception, there was a decline in the LoS statistics over time for all diagnoses, all injury diagnoses, each body site of injury investigated, severity strata, and the ICD-HS diagnoses. CONCLUSIONS: Reductions in median and geometric mean LoS over time, as well as reductions in the proportion exceeding selected LoS thresholds, were due to factors other than reductions in the incidence of serious injury; for example, changes in service delivery over time. An LoS threshold should not be used as a proxy for severity of injury if the goal is to monitor time trends in injury incidence.

Prospective outcomes of injury study.

BACKGROUND: In New Zealand (NZ), 20% of adults report a disability, of which one-third is caused by injury. No prospective epidemiological studies of predictors of disability following all-cause injury among New Zealanders have been undertaken. Internationally, studies have focused on a limited range of predictors or specific injuries. Although these studies provide useful insights, applicability to NZ is limited given the importance of NZ's unique macro-social factors, such as NZ's no-fault accident compensation and rehabilitation scheme, the Accident Compensation Corporation (ACC). OBJECTIVES: (1) To quantitatively determine the injury, rehabilitation, personal, social and economic factors leading to disability outcomes following injury in NZ. (2) To qualitatively explore experiences and perceptions of injury-related outcomes in face-to-face interviews with 15 Maori and 15 other New Zealanders, 6 and 12 months after injury. SETTING: Four geographical regions within NZ. DESIGN: Prospective cohort study with telephone interviews 1, 4 and 12 months after injury. PARTICIPANTS: 2500 people (including 460 Maori), aged 18-64 years, randomly selected from ACC's entitlement claims register (people likely to be off work for at least 1 week or equivalent). DATA: Telephone interviews, electronic hospital and ACC injury data. Exposures include demographic, social, economic, work-related, health status, participation and/or environmental factors. OUTCOME MEASURES: Primary: disability (including WHODAS II) and health-related quality of life (including EQ-5D). Secondary: participation (paid and unpaid activities), life satisfaction and costs. ANALYSIS: Separate regression models will be developed for each of the outcomes. Repeated measures outcomes will be modelled using general estimating equation models and generalised linear mixed models.

Accuracy of injury coding under ICD-10-AM for New Zealand public hospital discharges.

OBJECTIVE: To determine the accuracy in coding for principal injury diagnosis (PDx), external cause, place of occurrence, and activity codes under the Australian Modification of the International Classification of Disease, 10th Revision (ICD-10-AM) for public hospital discharges in New Zealand. METHOD: A simple random sample of 1800 injury discharges was selected from the National Minimum Dataset (NMDS) of hospital discharges from July 2001 to June 2004. Records were obtained and coded by the Senior Advisor in Clinical Coding (SACC) independently of the codes already recorded in the NMDS. RESULTS: Of injury discharges selected from the NMDS, 2% were not coded with a PDx of injury by the SACC. Fourteen percent of the PDxs and 26% of the external cause codes (E-codes V01-Y89) had inaccuracies in the first, second, or third characters. Variation in the accuracy of the PDxs and E-codes was obvious by diagnostic and E-code groupings; 22% of the place of occurrence codes (Y92) and 29% of the activity codes (Y93) were incorrect. Accuracy of the PDxs and E-codes was related to the clarity of the documentation in the medical records. CONCLUSIONS: For countries that are considering implementing ICD-10 or one of its variants, these findings provide insight into possible limitations of the classification and offer guidance on where the focus of training should be placed. For countries that have historical data coded according to ICD-10-AM, these results suggest that some specific estimates of injury and external-cause incidence may need to be treated with caution.

Improving the predictive ability of the ICD-based Injury Severity Score.

OBJECTIVE: To assess whether the use of integrated hospitalization and mortality data sources and/or the inclusion of comorbidity improve the predictive ability of the International Classification of Disease (ICD)-based Injury Severity Score (ICISS). DESIGN: Models using either the ICISS based solely on hospital discharge data or one of nine modified ICISSs as the predictor variable were assessed on their ability to predict survival using logistic regression modeling. SETTING: New Zealand. Patients or SUBJECTS: Inpatients, with an S00-T89 ICD-10-AM principal diagnosis, and fatalities, with any S00-T89 ICD-10-AM diagnosis, occurring in 2000-2003. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Models were compared in terms of their discrimination (concordance), calibration, and goodness-of-fit. RESULTS: 186 835 cases including 9968 deaths met the inclusion criterion. The modified ICISS that included both mortality data and Charlson comorbid conditions at the ICD-10-AM level had the best concordance and high calibration. Calibration curves indicated that scores using hospital discharge data only to calculate survival risk ratios underestimated mortality, whereas scores using hospital discharge and mortality data overestimated mortality. CONCLUSIONS: Valid measurement of injury severity is important for both meaningful research and surveillance and to assist in classifying information to meet specific injury policy, prevention, and control needs. This study suggests that the predictive ability of ICISS would be improved if both mortality and comorbidity data were included in its calculation.

Accuracy of injury coding under ICD-9 for New Zealand public hospital discharges.

OBJECTIVE: To determine the level of accuracy in coding for injury principal diagnosis and the first external cause code for public hospital discharges in New Zealand and determine how these levels vary by hospital size. METHOD: A simple random sample of 1800 discharges was selected from the period 1996-98 inclusive. Records were obtained from hospitals and an accredited coder coded the discharge independently of the codes already recorded in the national database. RESULTS: Five percent of the principal diagnoses, 18% of the first four digits of the E-codes, and 8% of the location codes (5th digit of the E-code), were incorrect. There were no substantive differences in the level of incorrect coding between large and small hospitals. CONCLUSIONS: Users of New Zealand public hospital discharge data can have a high degree of confidence in the injury diagnoses coded under ICD-9-CM-A. A similar degree of confidence is warranted for E-coding at the group level (for example, fall), but not, in general, at higher levels of specificity (for example, type of fall). For those countries continuing to use ICD-9 the study provides insight into potential problems of coding and thus guidance on where the focus of coder training should be placed. For those countries that have historical data coded according to ICD-9 it suggests that some specific injury and external cause incidence estimates may need to be treated with more caution.

Correct and incorrect use of child restraints: results from an urban survey in New Zealand.

This study describes the incorrect use of child restraints among car drivers with young children and examines factors that may influence their misuse. A cross-sectional survey was undertaken in supermarket car parks with car drivers travelling with children under the age of 8 years. The main measure was errors in child restraint use. Short interviews were conducted with 1113 drivers with a close inspection of the child restraints used in the vehicles. Only 4% of children were unrestrained but 64% of drivers made at least one error in restraint use. Most respondents thought using a restraint was easy, but 65% of these drivers made at least one error. Child restraints are used, but many are incorrectly fitted and/or have the child incorrectly placed in them. Correct use is a moderately complex task. Restraint systems need to be designed to minimize the opportunity for error and maximize safety.

Screening for intestinal parasites in recently arrived children from East Africa.

BACKGROUND: Intestinal parasitic carriage is common in East African populations with a wide spectrum of clinical severity. There are scant data on the rates of carriage in East African immigrants to Australia. This study describes the prevalence of and risk factors for intestinal parasite carriage among children recently arrived from East African countries. METHODS: Children aged 0-17 years, who attended an outpatient clinic, were born in East Africa and had immigrated since 1998 were eligible to participate. A single preserved stool specimen was collected for faecal microscopy, and blood tests were conducted for Strongyloides and Schistosoma serology, full blood examination and serum ferritin. RESULTS: One hundred and thirty-five children (median age 8.1 years, range 1.0-17.5) participated, of whom 133 (99%) provided a stool specimen. Parasites were detected in 50% of samples, and 18% of children carried a possibly pathogenic species. No child was symptomatic at diagnosis. Positive or equivocal serology occurred in 11% of children for Strongyloides and 2% for Schistosoma. Anaemia and iron deficiency were detected in 16% of all children. Those carrying an intestinal parasite were older (mean age 9.8 vs 7.4 years, P= 0.002) and less likely to be anaemic (odds ratio 0.37, 95% confidence interval 0.14-0.96) than those who were not carriers. CONCLUSIONS: Carriage of intestinal parasites is common among children from East Africa. Those carrying pathogenic organisms require treatment and follow up to ensure eradication. The results of this survey support the need for routine assessment of newly arrived immigrants from East Africa for intestinal parasites, anaemia and iron deficiency.

Predicting BMI in young adults from childhood data using two approaches to modelling adiposity rebound.

OBJECTIVE: To identify the age of adiposity rebound and the value of its associated BMI and examine their association with BMI at ages 18 and 21 y for males and females. DESIGN: A longitudinal study of a large cohort of people born in Dunedin, New Zealand between 1972-1973. SUBJECTS: Four hundred and seventy-four males and 448 females aged between birth and 21 y. MEASUREMENTS: BMI was derived from measurements of weight and height made when the participants were born and at intervals from age 3-21 y. RESULTS: When a random coefficients model was fitted to the data for those who had five or more measures of BMI between age 3 and age 18y, adiposity rebound occurred at 6.0 y of age for boys and 5.6y for girls. The values of BMI associated with these were 15.7 kg/m2 for boys and 15.5 kg/m2 for girls. The correlations between age at adiposity rebound and BMI at ages 18 and 21 y were between -0.72 and -0.65 for boys and -0.59 and -0.47 for girls. These were higher than those derived from fitting individual curves or from deriving the adiposity rebound from data collected up to age 11 y. The correlation between BMI at age 7y and BMI at ages 18 and 21 y were 0.70 and 0.61 for boys and 0.56 and 0.52 for girls. The correlations between measures of skeletal maturity at age 7y and adiposity rebound were statistically significant for boys but not for girls. CONCLUSIONS: BMI in early adulthood was associated with both age of adiposity rebound and BMI at that age. As the correlations between BMI at age 7 y and BMI at ages 18 and 21 y were similar in magnitude, BMI at age 7 y may be a more practical way of predicting BMI in early adulthood.

From general practitioner to family physician.

A plea for the recognition of expertise in general practice by the medical authorities of this country is made, and a scheme for the registration of a higher degree in family medicine is suggested.