Quality of life following hip fractures: results from the Norwegian hip fracture register

Patients operated due to an acute hip fracture and reported to the NHFR from 2005 to 2012 were eligible for inclusion in the present study. As of December 31, 2012 there were 63,231 hip fractures recorded in the NHFR. The four months questionnaire had been sent to 37,968 patients and the twelve months questionnaire had been sent to 30,400 patients. The response rates to the questionnaires were 54 % at four months and 49 % at twelve months. Only patients who had received and completely filled in both the four- and twelve months questionnaires were included in the study. Patients who died before time of the planned follow-up and patients with too short follow-up did not received questionnaires. Further, due to economical/administrative reasons only a randomly selected group of patients in the time period 2007-2009 received the questionnaires. A total of 29,997 patients received both questionnaires. Of these patients 10,324 (34 %) answered both questionnaires completely, and were accordingly included in the study (Fig. 1).

The baseline characteristics for responders and non-responders are presented in Table 1. The responders were statistically significant younger, healthier according to the ASA classification, and less cognitively impaired compared to the non-responders. Further, there were small, but still statistically significant differences both in type of fracture and type of surgery (Table 1).

Preoperatively, the majority of the patients reported no problems in each of the five dimensions of the EQ-5D (Table 2). Compared to their preoperative status, the proportion of patients reporting problems at four months more than doubled in the dimensions regarding mobility and self-care, and almost doubled regarding usual activities and pain/discomfort. At twelve months postoperatively there was still a marked increase of patients reporting problems in these dimensions compared to preoperatively. For the last dimension (Anxiety/depression) the changes were less evident.

When performing sub-analyses for each of the five EQ-5D dimensions including only patients with no reported problems preoperatively, there was still a high proportion of patients reporting problems after four and twelve months (Table 3). In the group of patients reporting no problems in walking preoperatively 71 % reported problems after 4 months and 58 % had problems after 12 months postoperatively. Corresponding results were found for the ability of performing self-care and for usual activities where 29 % and 53 % respectively reported problems twelve months postoperatively. As much as 60 % of the patients with no preoperative pain reported pain twelve months postoperative.

The quality of life by the EQ-5D proportions for the different fracture types is presented in Additional file 1. The patients operated due to trochanteric fractures reported statistically significant more problems preoperatively than the other fracture types. The patients operated due to a FFN reported statistically significant lesser problems at all follow-ups compared to other fracture types. Regarding anxiety and depression the differences were less evident, but still better results were reported for the FFNs. The changes in severity level from preoperative to the four months follow up for each of the dimensions of the EQ-5D and for each fracture type are shown in Fig. 2. More than half of the patients with FFN reported no changes in the severity level of each dimension at four months postoperatively compared to their preoperative quality of life. Compared to patients with FFN, a higher proportion of patients with trochanteric and in particular subtrochanteric fractures reported increased problems in all dimensions at four months postoperative. For all fracture types only a small proportion of patients reported less problems four months postoperative compared to their preoperative functional level.

Figure 3 shows the mean VAS pain from the operated hip at the two postoperative follow-ups. Differences in mean pain between the different fracture types were found at all follow-ups; i.e. patients operated for a FFN reported the lowest pain at all follow-ups compared to trochanteric and subtrochanteric fractures. For all fracture types the mean pain decreased over time. However, the mean pain after 12 months was still between 22 and 28, indicating that pain from the operated hip still may be an issue for at least some of the patients.

The youngest age group (<70 years) reported the best quality of life in all dimensions except pain/discomfort at all follow-ups compared to the older age groups [see Additional file 2]. However, even in the youngest patient group problems in all dimensions were frequent following hip fractures. After twelve months more than 56 % of the youngest patients had problems in walking, 23 % had problems with self-care, and 51 % had problems performing usual activities. The oldest age group (>80 years) reported problems most frequently. The differences between the age groups were statistically significant in all dimensions and at all follow-ups.

The strengths of our results are the high number of patients and that we present nation-wide results. The response rates of the 4 and the 12 months questionnaires were approximately 50 % for the living patients, and the response rate of patients answering both questionnaires was only 34 %. The reason for this low response rate is probably high age and high degree of comorbidity among the patients. Reminders could probably have improved the response rate. The study population represented a selected group of patients as they have all survived the first 12 months after surgery and answered the 12 months questionnaire. The results showed that they were younger and healthier than the non-responders. This is also verified when comparing the baseline characteristics of patients in the present study with earlier studies from the Norwegian Hip Fracture Register, which has reported on older and more comorbid patients [2, 29‐33]. Accordingly, one major limitation of the present study is the risk for selection bias. Thus, the results reported in this study may be a best-case scenario excluding the oldest and most comorbid patients with the expected worst quality of life. However, even if a selection bias exists, the absolute number of patients reporting problems following hip fractures was still high.

One other limitation of the study is that it was not a randomized trial and, accordingly, no matched control group. We cannot conclude that all the changes in quality of life over time were caused by the hip fracture itself. To some extent these changes were probably part of the natural life course for these old and frail patients irrespective of the fracture. The EQ-5D index score has been thoroughly validated in several studies including elderly hip fracture patients [34‐38]. As far as we know, similar validation of the EQ-5D health profiles has not been done. However, the use of EQ-5D health profiles as used in the present study is one of the recommended methods to present quality of life results according to the EuroQol group [39]. Finally, a recall bias may exist as the preoperative EQ-5D data was retrospectively recorded four months after surgery. Two studies have found moderate or good correlation when comparing recalled data and prospective data in outcome studies after arthroplasties [40, 41]. Consequently we believe we largely can trust the recalled preoperative data.